CN110247743B - Random access method, device, equipment and storage medium - Google Patents

Abstract

The embodiment of the invention discloses a random access method, a device, equipment and a storage medium, wherein the method comprises the following steps: dividing a PRACH channel into m public RA sub-channels and n special RA sub-channels; wherein one said common RA sub-channel is used for random access of more than one UE, and one said dedicated RA sub-channel is used for random access of one UE; m and n are integers of 1 or more; and sending the configuration information of the m public RA sub-channels and the configuration information of the n special RA sub-channels to corresponding UE to finish the random access process.

Description

Random access method, device, equipment and storage medium

Technical Field

The present invention relates to a coordinated multi-point transmission technology, and in particular, to a random access method, apparatus, device, and storage medium.

Background

In a CoMP (Coordinated Multiple Points Transmission/Reception) multi-UE (User Equipment) communication system, in order to reduce mutual interference between UEs (Coordinated terminals) and non-UEs (non-Coordinated terminals), a central unit is facilitated to recognize UEs during centralized monitoring, and a PRACH (Physical Random Access Channel) is frequency division multiplexed into two RA (Random Access) subchannels and a guard interval therebetween. The two sub-channels correspond to two different Preamble root sequences respectively. The random access procedures of CoUEs and non-CoUEs are respectively carried out on different RA sub-channels, thereby avoiding the interference between the two.

The existing PRACH sub-channel division technology only solves the mutual interference between CoUEs and non-CoUEs. The problem of collision generated by different UEs in the contention-based random access process in the same RA subchannel is not solved.

Disclosure of Invention

In view of this, embodiments of the present invention provide a random access method, apparatus, device, and storage medium for solving at least one problem in the prior art, which can solve the collision problem generated by different UEs in the contention-based random access process in the same RA subchannel.

The technical scheme of the embodiment of the invention is realized as follows:

the embodiment of the invention provides a random access method, which comprises the following steps:

dividing a PRACH channel into m public RA sub-channels and n special RA sub-channels; wherein one said common RA sub-channel is used for random access of more than one UE, and one said dedicated RA sub-channel is used for random access of one UE; m and n are integers of 1 or more;

and sending the configuration information of the m public RA sub-channels and the configuration information of the n special RA sub-channels to corresponding UE to finish the random access process.

The embodiment of the invention provides a random access method, which comprises the following steps:

the UE receives the configuration information of the m public RA sub-channels and the configuration information of the n special RA sub-channels sent by the base station;

UE selects a public Preamble sequence and a special Preamble sequence, and selects a public RA sub-channel and a special RA sub-channel according to the configuration information of the m public RA sub-channels and the configuration information of the n special RA sub-channels;

and the UE sends a dedicated Preamble sequence on the selected dedicated RA sub-channel and sends a common Preamble sequence on the selected common RA sub-channel.

The embodiment of the invention provides a terminal, which comprises a memory, a processor and a computer program which is stored on the memory and can run on the processor, wherein the processor executes the program to realize the steps in the random access method of the terminal side.

The embodiment of the invention provides a base station, which comprises a memory, a processor and a computer program which is stored on the memory and can run on the processor, wherein the processor executes the program to realize the steps in the random access method of the base station side.

An embodiment of the present invention provides a computer-readable storage medium, on which a computer program is stored, where the computer program, when executed by a processor, implements the steps in the random access method on the base station side; alternatively, the computer program realizes the steps in the random access method at the terminal side when executed by the processor.

An embodiment of the present invention provides a random access apparatus, where the apparatus includes:

a dividing unit, configured to divide a PRACH channel into m public RA subchannels and n dedicated RA subchannels; wherein one said common RA sub-channel is used for random access of more than one UE, and one said dedicated RA sub-channel is used for random access of one UE;

a first sending unit, configured to send the configuration information of the m public RA subchannels and the configuration information of the n dedicated RA subchannels to corresponding UEs, so as to complete a random access procedure.

An embodiment of the present invention provides a random access apparatus, where the apparatus includes:

a second receiving unit, configured to receive configuration information of the m public RA subchannels and configuration information of the n dedicated RA subchannels sent by a base station;

a selecting unit, configured to select a common Preamble sequence and a dedicated Preamble sequence, and select a common RA subchannel and a dedicated RA subchannel according to the configuration information of the m common RA subchannels and the configuration information of the n dedicated RA subchannels;

and a second sending unit, configured to send a dedicated Preamble sequence on the selected dedicated RA subchannel, and send a common Preamble sequence on the selected common RA subchannel.

In the embodiment of the invention, a PRACH channel is divided into m public RA sub-channels and n special RA sub-channels; wherein one said common RA sub-channel is used for random access of more than one UE, and one said dedicated RA sub-channel is used for random access of one UE; m and n are integers of 1 or more; sending the configuration information of the m public RA sub-channels and the configuration information of the n special RA sub-channels to corresponding UE to complete a random access process; therefore, the problem of collision generated by different UEs in the process of contention-based random access in the same RA subchannel can be solved.

Drawings

Fig. 1A is a schematic flow chart illustrating an implementation of a random access method according to an embodiment of the present invention;

fig. 1B is a schematic diagram illustrating division of PRACH subchannels in an embodiment of the present invention;

fig. 2 is a schematic flow chart illustrating an implementation of sending MSG1 by the UE according to the embodiment of the present invention;

fig. 3 is a schematic diagram of a flow chart of implementing TA estimation at an eNB end according to an embodiment of the present invention;

fig. 4 is a schematic diagram of a flow of implementing random access after dividing PRACH subchannels in an embodiment of the present invention;

fig. 5A is a diagram illustrating a correlation peak detection result (a) of a common RA subchannel according to an embodiment of the present invention;

fig. 5B is a diagram illustrating a correlation peak detection result (B) of the common RA subchannel according to the embodiment of the present invention;

fig. 5C is a diagram illustrating the location and size of correlation peaks of RA sub-channels according to an embodiment of the present invention;

FIG. 5D is a diagram illustrating correlation peak determination (UE1) according to an embodiment of the present invention;

fig. 6 is a schematic structural diagram of a random access apparatus according to an embodiment of the present invention;

fig. 7 is a diagram of a hardware entity of a random access device according to an embodiment of the present invention.

Detailed Description

The PRACH is an access channel when the UE starts to initiate a call, and after receiving the FPACH response message, the UE sends an RRC Connection Request message on the PRACH channel according to the information indicated by the Node B to establish an RRC Connection. The UE achieves uplink access and synchronization with the LTE system through the uplink RACH.

The Preamble transmitted on the PRACH is generated by cyclic shift of Zadoff-Chu (zc) sequences, which are derived from root sequences of one or more Zadoff-Chu sequences, the sequence length is 839 or 139, and the subcarrier spacing in the PRACH is 1.25K. There are 64 preamble sequences in a cell, the network side configures the preamble sequences that can be used in the cell, and broadcasts the first ZC root sequence by using the parameter rootsequence index (root sequence index value, which is a value between 0 and 837) in SIB2, and cyclically shifts the root sequence according to a certain rule to generate a corresponding PRACH preamble sequence.

The eNodeB sends RACH-ConfigCommon (RACH common configuration information) through broadcasting SIB-2, and tells UE the grouping of Preamble, the threshold value of Msg3 size, power configuration and the like. When the UE initiates random access, a suitable Preamble is selected according to the possible Msg3 size, pathloss and the like.

CoMP refers to a plurality of geographically separated transmission points that cooperatively participate in data (PDSCH) transmission for one terminal or jointly receive data (PUSCH) transmitted by one terminal.

In a CoMP multi-UE communication system, in order to reduce mutual interference between UEs and non-UEs, it is convenient for a central unit to recognize UEs during centralized monitoring, frequency division multiplexing a PRACH channel into two RA subchannels and a guard interval therebetween. The two sub-channels correspond to two different Preamble root sequences respectively. The random access procedures of CoUEs and non-CoUEs are respectively carried out on different RA sub-channels, thereby avoiding the interference between the two.

The existing PRACH sub-channel division technology only solves the mutual interference between CoUEs and non-CoUEs. The problem of collision generated by different UEs in the contention-based random access process in the same RA subchannel is not solved.

The technical solution of the present invention is further elaborated below with reference to the drawings and the embodiments.

The present embodiment provides a random access method, which can solve the collision problem generated by different UEs in the same RA subchannel during contention-based random access, and the method is applied to a base station, where the function implemented by the method may be implemented by a processor in the base station calling a program code, and certainly the program code may be stored in a computer storage medium, and as can be seen, the base station at least includes a processor and a storage medium.

Fig. 1A is a schematic diagram of an implementation flow of a random access method according to an embodiment of the present invention, as shown in fig. 1A, the method includes:

step S101, dividing PRACH channel into m public RA sub-channels and n special RA sub-channels; wherein one said common RA sub-channel is used for random access of more than one UE, and one said dedicated RA sub-channel is used for random access of one UE; m and n are integers of 1 or more;

wherein, more than one includes one, two, three, etc., that is, the common RA subchannel can access one UE or more than two UEs, while the dedicated RA subchannel can access only one UE.

Step S102, the configuration information of the m public RA sub-channels and the configuration information of the n special RA sub-channels are sent to the corresponding UE, so as to complete the random access process.

Wherein, m is 1, n is an integer greater than or equal to 1, and n is an estimated value greater than or equal to the number of UEs performing random access simultaneously in the cell; that is, the PRACH channel is divided into one common RA subchannel and n dedicated RA subchannels by frequency division multiplexing.

Wherein a guard interval is provided between each RA subchannel of the m common RA subchannels and the n dedicated RA subchannels.

In other embodiments, the RA subchannels respectively transmit Preamble sequences generated by different ZC root sequences, the length of the common Preamble sequence is consistent with the length of the corresponding common RA subchannel, and the length of the dedicated Preamble sequence is the same as the length of the corresponding dedicated RA subchannel. That is, the length of the common Preamble sequence is consistent with the length of the common RA subchannel transmitting the common Preamble sequence, and the length of the dedicated Preamble sequence is the same as the length of the dedicated RA subchannel transmitting the dedicated Preamble sequence. The Preamble is a short for random access Preamble, that is, a random access Preamble, and is used for identifying the UE identity during random access.

Wherein, the length of each Preamble sequence needs to be less than or equal to the number of subcarriers occupied by the corresponding RA subchannel. The method is applied to a random access process based on competition in a wireless access system, or the method is applied to a random access process of a user under the condition of switching in the wireless access system; or, the method is applied to the random access process of the user under the condition that the air interface is out of step in the wireless access system. The frequency domain resources of the common RA sub-channel and the frequency domain resources of the dedicated RA sub-channel are generated statically in the contention-based random access process, and the frequency domain resources of the common RA sub-channel and the dedicated RA sub-channel can be generated dynamically or statically under the condition of switching or air interface desynchronization; in addition, in the contention-based random access process, one dedicated RA subchannel UE is selected at will, and the dedicated RA subchannel is assigned to the fixed UE for use through the indication message when the handover or the air interface is out of synchronization.

In other embodiments, when the method is applied to a contention-based random access procedure in a wireless access system, frequency domain resources of m common RA subchannels and frequency domain resources of n dedicated RA subchannels are statically generated; the sending the configuration information of the m public RA subchannels and the configuration information of the n dedicated RA subchannels to the corresponding UE includes:

and sending the configuration information of the m public RA subchannels and the configuration information of the n special RA subchannels to the UE in the cell through a broadcast message. The broadcast message also carries state information, and the state information is used for informing the UE of performing random access in the cell by using a PRACH sub-channel division mode. The state information occupies the expanded 1 bit.

In other embodiments, when the method is applied to a random access procedure of a user in a handover situation in a wireless access system, the frequency domain resources of the m common RA subchannels and the frequency domain resources of the n dedicated RA subchannels are statically or dynamically generated; the sending the configuration information of the m public RA subchannels and the configuration information of the n dedicated RA subchannels to the corresponding UE includes: and sending the configuration information of the m public RA sub-channels and the configuration information of the n special RA sub-channels to UE of users under the condition of switching in a cell through a HANDOVER COMMAND message.

In other embodiments, when the method is applied to a random access process of a user in a wireless access system under the condition of air interface desynchronization, frequency domain resources of m public RA subchannels and frequency domain resources of n dedicated RA subchannels are generated statically or dynamically; the sending the configuration information of the m public RA subchannels and the configuration information of the n dedicated RA subchannels to the corresponding UE includes: and sending the configuration information of the m public RA sub-channels and the configuration information of the n special RA sub-channels to UE under the condition of air interface desynchronization in a cell through a PDCCH Order message.

In other embodiments, the method further comprises:

step S11, receiving at least one UE special Preamble sequence sent on special RA sub channel, and public Preamble sequence sent on public RA sub channel;

step S12, if the UE with random access collision is determined by detecting the n dedicated RA subchannels and the m common RA subchannels, determining a TA value from a correlation peak of the common RA subchannel and a correlation peak of the dedicated RA subchannel of each UE of the UEs with random access collision.

In other embodiments, the determining the UE having the random access collision by detecting the n dedicated RA subchannels and the m common RA subchannels includes:

step S121, detecting a first number p1 of occupied ones of the n dedicated RA subchannels;

step S122, detecting a second number p2 of Preamble sequences with different index values in the m public RA sub-channels;

at step S123, if the first number p1 is greater than the second number p2, the UEs with random access collision are determined.

In other embodiments, the method further comprises:

step S21, receiving at least one UE special Preamble sequence sent on special RA sub channel, and public Preamble sequence sent on public RA sub channel;

step S22, finding that only one dedicated RA sub-channel is occupied by detecting the n dedicated RA sub-channels, and completing a random access procedure to the corresponding UE through the common RA sub-channel or the occupied dedicated RA sub-channel.

In other embodiments, the method further comprises:

step S31, receiving at least one UE special Preamble sequence sent on special RA sub channel, and public Preamble sequence sent on public RA sub channel;

step S32, detecting a first number p1 of the n dedicated RA sub-channels being occupied;

step S33, detecting the second number p2 of Preamble sequences with different index values in the m public RA sub-channels;

step S34, if the first number p1 is equal to the second number p2, determining that there is no access conflict; and finishing a random access process for the corresponding UE through the public RA sub-channel or the occupied special RA sub-channel.

In other embodiments, the determining the TA value from the correlation peak of the common RA subchannel and the correlation peak of the dedicated RA subchannel of each of the UEs with random access collision includes:

step S41, if the UE with random access conflict can be distinguished according to the time delay of the special RA sub-channel and the time delay of the public RA sub-channel, the correlation peak of the public RA sub-channel of each UE with random access conflict and the correlation peak of the special RA sub-channel are superposed;

step S42, determining the TA value of each UE in the UEs with random access conflict according to the superposition value and the corresponding decision threshold.

In other examples, the determining the TA value using the correlation peak of the common RA subchannel and the correlation peak of the dedicated RA subchannel for each of the UEs with random access collision includes:

if the UE with random access conflict can not be distinguished according to the time delay of the special RA sub-channel and the time delay of the public RA sub-channel, averaging the estimation results of the correlation peak of the special RA sub-channel and the correlation peak of the public RA sub-channel;

and taking the average value as the TA value of each UE in the UEs with random access collision.

The present embodiment provides a random access method, which can solve the collision problem generated by different UEs in the same RA subchannel during contention-based random access, and the method is applied to the UEs, where the functions implemented by the method may be implemented by a processor in the UE calling a program code, and certainly the program code may be stored in a computer storage medium, and as a result, the UE at least includes a processor and a storage medium.

Step S51, the UE receives the configuration information of the m public RA sub-channels and the configuration information of the n special RA sub-channels sent by the base station;

step S52, UE selects common Preamble sequence and special Preamble sequence, and selects a common RA sub-channel and a special RA sub-channel according to the configuration information of m common RA sub-channels and the configuration information of n special RA sub-channels;

step S53, the UE sends a dedicated Preamble sequence on the selected dedicated RA subchannel, and sends a common Preamble sequence on the selected common RA subchannel.

In another embodiment, the receiving, by the UE, the configuration information of the m common RA subchannels and the configuration information of the n dedicated RA subchannels sent by the base station includes:

and when the UE is in a contention-based random access process, receiving the configuration information of the m public RA sub-channels and the configuration information of the n special RA sub-channels through a broadcast message.

In another embodiment, the receiving, by the UE, the configuration information of the m common RA subchannels and the configuration information of the n dedicated RA subchannels sent by the base station includes:

and when the UE is in a random access process under the condition of switching, receiving the configuration information of the m public RA sub-channels and the configuration information of the n special RA sub-channels through a HANDOVER COMMAND message.

In another embodiment, the receiving, by the UE, the configuration information of the m common RA subchannels and the configuration information of the n dedicated RA subchannels sent by the base station includes:

and when the UE is in the random access process under the condition of air interface desynchronization, receiving the configuration information of the m public RA sub-channels and the configuration information of the n special RA sub-channels through a PDCCH Order message.

Under the conditions of multi-base station CoMP and dense UE, a plurality of UEs can send preambles with the same Index at the same time-frequency position with certain probability. For contention-based random access, its Preamble Index is randomly selected by the UE. If the indexes of the Preambles in the same time-frequency position are the same, access collision will occur, which results in extra random access delay.

In the embodiment of the invention, a PRACH channel is divided into a public RA sub-channel and n special RA sub-channels through frequency division multiplexing, and a certain guard interval is reserved between the RA sub-channels; wherein n is more than or equal to the estimated value of the number of the UE which simultaneously carries out random access in the cell. The common RA subchannel is used for random access for all UEs, and each UE individually corresponds to a different dedicated RA subchannel. And sending a Preamble sequence generated by different ZC root sequences on each RA subchannel respectively, wherein the length of the Preamble sequence is correspondingly adjusted according to the length of the divided RA subchannel. The length of the common Preamble sequence should be identical to that of the common RA subchannel, and the length of the dedicated Preamble sequence should be identical to that of the dedicated RA subchannel.

In practice, the frequency bandwidth of the common RA subchannel is greater than the frequency bandwidth of one dedicated RA subchannel.

As shown in fig. 1B, n is 3, that is, the PRACH channel is divided into one common RA subchannel and 3 dedicated RA subchannels by frequency division multiplexing, and a certain guard interval is left between RA subchannels, for example, a guard interval is left between the common RA subchannel and the dedicated RA subchannel (1), a guard interval is left between the dedicated RA subchannel (1) and the dedicated RA subchannel (2), and a guard interval is left between the dedicated RA subchannel (2) and the dedicated RA subchannel (3).

The following points need to be noted when generating the Preamble sequence: 1) generating a Preamble sequence on each RA subchannel; 2) each Preamble sequence is still generated by a ZC root sequence to ensure its correlation; 3) the length of each Preamble sequence needs to be less than or equal to the number of subcarriers occupied by the corresponding subchannel.

The technical scheme provided by the embodiment of the invention can be used for at least the following two use scenes, namely the random access process based on competition in the wireless access system and the random access process of the user under the condition of switching or air interface desynchronization in the wireless access system.

In the two scenarios, the technical scheme provided by the embodiment of the invention reduces the collision probability through the public RA sub-channel and the special RA sub-channel, thereby improving the success rate of random access and further reducing the time delay of random access. In the above two scenarios, the usage of RA subchannels may be different. In scenario 1, when the RA is generally used in a contention-based random access procedure, a common RA subchannel and a dedicated RA subchannel are generated in a frequency division multiplexing manner and in a static reservation manner at an initial stage of a system, and the RA subchannel is used in the contention-based random access procedure and notifies Users (UEs) in a cell through a broadcast message. In addition, "generally used" in scenario 1 is that the dedicated RA subchannel is not specifically targeted to a certain UE, and the user randomly selects the dedicated RA subchannel. In scenario 2, when the RA sub-channel is used for a random access procedure of a user under a handover or air interface out-of-sync condition, the usage mode of the RA sub-channel is the random access procedure of the user under the handover or air interface out-of-sync condition, and the common RA sub-channel and the dedicated RA sub-channel are generated as needed when handover or air interface out-of-sync occurs, that is, scenario 2 is temporarily allocated based on event trigger, where the event trigger includes "time when handover or air interface out-of-sync occurs". In scenario 2, the eNB may notify configuration information of a public RA subchannel and a dedicated RA subchannel through configuration information dedicated to a user, where the dedicated RA subchannel is dedicated to handover or air interface out-of-synchronization UE. The dedicated configuration information may be an ANDOVER COMMAND message in the case of handover, and may be a Physical Downlink Control Channel (PDCCH) Order message in the case of gap desynchronization.

For contention-based random access procedures, when the eNB completes the common RA subchannel and dedicated RA subchannel generation. One potential way to inform the UEs within a cell is through SIB messaging. For example, the eNB broadcasts an SIB-2 message, where the SIB-2 message includes, in addition to the configuration information, 1-bit status information (supplemental-Config) for notifying the UE of performing random access in the cell by using the PRACH subchannel division method. The 1-bit state information is 1-bit information extended on the original SIB-2 message structure. The extended SIB-2 message structure is as follows:

radioResourceConfigCommon

rach-ConfigCommon

bcch-Config

pcch-Config

prach-Config

pdsch-ConfigCommon

pusch-ConfigCommon

ul-ReferenceSignalsPUSCH

soundingRS-UL-ConfigCommon

uplinkPowerControlCommon

subchannel-Config

ue-TimersAndConstants

freqInfo

for the random access process of the user under the condition of switching or air interface desynchronization, when the eNB temporarily completes the generation of the public RA sub-channel and the special RA sub-channel according to the requirement. One potential way to inform the UE of the HANDOVER is via a HANDOVER COMMAND (HANDOVER COMMAND) message. The eNB detects the uplink desynchronization and can inform the user of the information of the public RA subchannel and the special RA subchannel through a PDCCH Order message when the downlink data is sent.

In the embodiment, the PRACH channel is divided into frequency domains, and each Preamble sequence is designed according to the divided sub-channels to allow multiple users to access the base station at the same time, so that the access success rate is increased without sacrificing access delay, thereby increasing the access capacity of the access channel. The method comprises the division of PRACH sub-channels, the design of corresponding Preamble sequences on each sub-channel, the modification of SIB-2 message structures for switching access modes and the corresponding access process. The scheme provided by the embodiment can increase the utilization rate of frequency spectrum resources, thereby improving the average access success rate and finally improving the user experience in the cell.

The following is a specific example of an LTE PRACH subchannel application.

Fig. 2 is a schematic flow chart of an implementation of sending MSG1 by a UE according to an embodiment of the present invention, and as shown in fig. 2, the method includes:

step S201, UE randomly selects a Preamble Index and determines a public Preamble sequence to be sent;

step S202, UE randomly selects a special RA sub-channel and determines a special Preamble sequence to be sent;

step S203, determining a time-frequency position for sending the Preamble according to the configuration information in the SIB-2, and determining a corresponding RA-RNTI according to the time-frequency position;

and step S204, determining the target receiving power and transmitting the MSG 1.

As can be seen from the above, the UE first selects the Preamble indexes (the UE selects two Preamble indexes from the Preamble sequence group, which are the Index value of the common Preamble sequence and the Index value of the dedicated Preamble sequence, respectively), and determines the common Preamble sequence to be transmitted. Then, a dedicated RA subchannel is selected and the dedicated Preamble sequence transmitted on this RA subchannel is determined. According to the configuration information in the SIB-2, the UE can select the PRACH resource for sending the Preamble. In addition, the time-frequency location of the Preamble can determine the value of the RA-RNTI. And finally, after the target receiving power is determined, the Preamble can be sent with proper transmitting power.

Fig. 3 is a schematic diagram of a flow for implementing TA estimation at an eNB end according to an embodiment of the present invention, and as shown in fig. 3, the flow includes:

step S301, receiving a Preamble;

step S302, checking the special RA sub-channel;

step S303, judging whether a plurality of UEs exist, if so, entering step S304, and if not, entering step S308;

step S304, checking the common RA sub-channel;

step S305, judging whether conflict occurs, if yes, going to step S306, if no, going to step S308;

step S306, the special Preamble is related to the local Preamble;

step S307, calculating the offset position of the special sub-channel, and shifting and overlapping the result of the previous step to the public sub-channel;

step S308, the public Preamble is related to the local Preamble;

step S309, TA estimation is completed.

As can be seen from the above, after the eNB receives the Preamble sent by the UE, the eNB first detects the dedicated RA subchannel. If only one special RA subchannel is occupied, the method indicates that only one UE is accessed to the eNB currently, then the common RA subchannel is used for completing a random process, and meanwhile, a Preamble sequence on the common RA subchannel is used for completing TA estimation and received power estimation. If a plurality of special RA sub-channels are found to be occupied at the same time, a plurality of UE access to the eNB at the same time frequency position, and then the common RA sub-channel is detected. If there are multiple Preamble sequences with different indexes, then the common RA subchannel can be used to complete the random access process, and the TA estimation and the received power estimation of each UE can be completed through the Preamble sequences; if there is only one Preamble sequence on the common RA subchannel, it indicates that an access collision occurs, and TA estimation and received power estimation need to be completed with the assistance of the dedicated RA subchannel.

Since the time delay of the same UE on different RA subchannels is the same, the offset between the common RA subchannel and the dedicated RA subchannel of the UE is constant. The common Preamble and the dedicated Preamble of the UE are correlated to obtain a common correlation peak and a dedicated correlation peak of the UE. The dedicated correlation peaks are shifted so that they are superimposed on the common correlation peaks. This increases the amplitude of the common correlation peak to be determined. It should be noted that the time delay is a relative time delay, and in fig. 5C, taking "the PRACH channel frequency domain length is 839 subcarriers, one common RA subchannel with alength 419, two dedicated RA subchannels with a length 205, and two guard intervals with a length 5" as an example for explanation, the time delay of the UE1 in the common RA subchannel is 0, and the time delay of the UE1 in the dedicated RA subchannel 1 is also 0; the delay for UE2 on the common RA subchannel is 40 and UE2 selects dedicated RA subchannel 2, then the delay on dedicated RA subchannel 2 is also 40.

Fig. 4 is a schematic diagram of a flow of implementing random access after dividing PRACH subchannels according to an embodiment of the present invention, and as shown in fig. 4, the random access process includes:

step S401, the eNB sends an SIB2(System Information Block 2) message; wherein, the SIB2 message carries 1bit status information to tell the UE about the RPACH sub-channel division used; the RPACH configuration information is also carried;

step S402, UE sends Preamble sequence, the process includes: (1) UE randomly selects a Preamble Index; (2) UE sends public Preamble and special Preamble respectively;

step S403, the eNB sends an RAR to the UE, and the process includes: (1) the eNB detects a dedicated RA subchannel; (2) the eNB detects a common RA subchannel; (3) the eNB carries out TA estimation; (4) the eNB allocates TC-RNTI; (5) the eNB allocates uplink resources for the MSG 3;

step S404, the UE sends MSG3 to the eNB, and the process includes: (1) UE adjusts uplink synchronization; (2) the UE sends a unique identifier of the UE;

in step S405, the eNB performs conflict Resolution (conflict Resolution), which includes: (1) eNB conflict resolution; (2) the eNB converts the TC-RNTI into a C-RNTI;

after dividing PRACH sub-channels, through a complete random access process based on competition, UE adjusts uplink synchronization after obtaining TA estimation result and completes conflict resolution.

For convenience of explanation, the multi-UE TA estimation in this case is exemplified by a case where two UEs collide. Generally, the PRACH channel is divided into a common RA subchannel with alength 419, two dedicated RA subchannels with a length 205, and two guard intervals with a length 5, taking the frequency domain length of 839 subcarriers. The common RA subchannel corresponds to a ZC root sequence oflength 419, and the dedicated channel corresponds to a ZC root sequence of length 205.

When two UEs have random access collision, the two UEs use the Preamble sequence of the same Index on the common channel. As shown in fig. 5A, since the time delays of two UEs are different, two correlation peaks are obtained after performing correlation operation with the local Preamble sequence. The eNB cannot determine which UE each correlation peak corresponds to only using information obtained from the common RA subchannel, and therefore needs to introduce information of a private channel to determine. If the time delays of the two UEs are close, the positions of the two correlation peaks will be difficult to distinguish, as shown in fig. 5B, at this time, the TAs of the two UEs may be considered to be the same, and the average value of the estimation results of the two correlation peaks is taken as the finally estimated TA value.

If the delay difference between the two UEs is large enough, the two UEs can be distinguished by using the information on the dedicated channel. As can be seen from fig. 5C, the delay of the same UE is the same over the entire PRACH channel, so the offset of the common Preamble and the dedicated Preamble of the same UE in the frequency domain is also the same. The relative offset between correlation peaks on different RA subchannels belonging to the same UE is fixed. Therefore, the receiving end can superpose the correlation peak on the corresponding correlation peak of the common RA sub-channel by shifting the correlation peak on the dedicated RA sub-channel. As shown in fig. 5D, after two correlation peaks of the UE1 are superimposed, and then the decision threshold is 500, the correlation peak belonging to the UE1 can be decided, so as to estimate the TA value of the UE 1. Similarly, the TA value of the UE2 can be obtained by the same method.

As can be seen from the above, this embodiment provides a random access scheme based on subchannel division, which is applicable to a contention-based random access procedure or a user random access procedure in case of handover/air interface loss.

(1) In the process of contention-based random access, the division and generation of sub-channels are completed in the initial stage of the system, and users in a cell are informed. And in the random access process of the user under the condition of switching/air interface desynchronizing, triggering to immediately finish the sub-channel division and generation according to a switching or air interface desynchronizing event, and informing a specific user.

(2) The sub-channel division scheme is to divide the random access channel into a public RA sub-channel and n special RA sub-channels through frequency division multiplexing, and a certain guard interval is reserved between the RA sub-channels, wherein n is greater than or equal to the estimated value of the number of the UE which performs random access simultaneously in the cell.

(3) The common RA subchannel is used for random access for all UEs, and each UE corresponds to a different dedicated RA subchannel.

(4) The length of the common Preamble sequence should be less than or equal to the length of the common RA subchannel, and the length of the dedicated Preamble sequence should be less than or equal to the length of the dedicated RA subchannel.

(5) The problem of collision when a single sub-channel is adopted for random access can be solved through the joint correlation peak detection of the public sub-channel and the special sub-channel, and the TA estimation of the UE is further completed. The specific method may be to perform correlation on the common subchannel Preamble and the dedicated subchannel Preamble of the UE respectively to obtain a common correlation peak and a dedicated correlation peak of the UE. The dedicated correlation peaks are shifted so that they are superimposed on the common correlation peaks. This increases the amplitude of the common correlation peak to be determined.

(6) In the contention-based random access procedure, the eNB may notify the intra-cell user subchannel configuration information in a manner of SIBS-2. The IB-2 message contains, in addition to the configuration information, 1-bit status information for notifying the UE to perform random access in the cell by using the PRACH subchannel division method.

(7) In the random access process of the user under the condition of switching/air interface desynchronization, the mode of informing the specific user sub-channel configuration information by the eNB may be through a HANDOVER COMMAND/PDCCH Order message.

Compared with the prior art, the embodiment has the following advantages:

(1) in the process of random access based on competition, compared with the existing single sub-channel random access mode, the collision probability can be reduced, the success rate of random access is improved, and the random access time delay is reduced.

(2) Compared with the existing single sub-channel random access mode, the random access method has stronger robustness and improves the success rate of random access in the random access process under the condition of switching/air interface desynchronizing.

(3) In the contention-based random access process, compared with the existing single sub-channel random access mode, when a plurality of UEs conflict, the TA value of each UE is still estimated by the scheme, and the original scheme cannot be used.

(4) Compared with the existing single sub-channel random access mode, the random access user capacity and the resource utilization rate can be improved due to the fact that a plurality of sub-channels are used for access. It should be noted that: a single random access procedure may require more power because the UE needs to send messages on both the common RA subchannel and the dedicated RA subchannel. The random access success rate is improved, so that the overall power change is not large.

Based on the foregoing embodiments, an embodiment of the present invention provides a random access apparatus, including a first apparatus and a second apparatus, where each unit included in the first apparatus and each module included in each unit may be implemented by a processor in a base station; each unit included in the second apparatus and each module included in each unit may be implemented by a processor in the terminal; of course, the functions performed by the processor may also be implemented by logic circuits; in implementation, the processor may be a Central Processing Unit (CPU), a Microprocessor (MPU), a Digital Signal Processor (DSP), a Field Programmable Gate Array (FPGA), or the like.

Fig. 6 is a schematic diagram of a composition structure of a random access apparatus according to an embodiment of the present invention, and as shown in fig. 6, the apparatus includes afirst apparatus 600 and a second apparatus 610, where thefirst apparatus 600 includes a dividing unit 601 and a first sending unit 602, and the second apparatus 610 includes a second receiving unit 611, a selecting unit 612, and a second sending unit 613; wherein:

a dividing unit 601, configured to divide a PRACH channel into m public RA subchannels and n dedicated RA subchannels; wherein one said common RA sub-channel is used for random access of more than one UE, and one said dedicated RA sub-channel is used for random access of one UE;

a first sending unit 602, configured to send the configuration information of the m public RA subchannels and the configuration information of the n dedicated RA subchannels to corresponding UEs, so as to complete a random access procedure.

A second receiving unit 611, configured to receive configuration information of the m common RA subchannels and configuration information of the n dedicated RA subchannels sent by the base station;

a selecting unit 612, configured to select a common Preamble sequence and a dedicated Preamble sequence, and select a common RA subchannel and a dedicated RA subchannel according to the configuration information of the m common RA subchannels and the configuration information of the n dedicated RA subchannels;

a second sending unit 613, configured to send a dedicated Preamble sequence on the selected dedicated RA subchannel, and send a common Preamble sequence on the selected common RA subchannel.

Wherein, m is 1, n is an integer greater than or equal to 1, and n is an estimated value greater than or equal to the number of UEs performing random access simultaneously in the cell; that is, the PRACH channel is divided into one common RA subchannel and n dedicated RA subchannels by frequency division multiplexing.

Wherein a guard interval is provided between each RA subchannel of the m common RA subchannels and the n dedicated RA subchannels.

In other embodiments, the RA subchannels respectively transmit Preamble sequences generated by different ZC root sequences, the length of the common Preamble sequence is consistent with the length of the corresponding common RA subchannel, and the length of the dedicated Preamble sequence is the same as the length of the corresponding dedicated RA subchannel. That is, the length of the common Preamble sequence is consistent with the length of the common RA subchannel transmitting the common Preamble sequence, and the length of the dedicated Preamble sequence is the same as the length of the dedicated RA subchannel transmitting the dedicated Preamble sequence.

Wherein, the length of each Preamble sequence needs to be less than or equal to the number of subcarriers occupied by the corresponding RA subchannel. The method is applied to a random access process based on competition in a wireless access system, or the method is applied to a random access process of a user under the condition of switching in the wireless access system; or, the method is applied to the random access process of the user under the condition that the air interface is out of step in the wireless access system.

In other embodiments, when the method is applied to a contention-based random access procedure in a wireless access system, the first transmitting unit is configured to transmit the configuration information of the m common RA subchannels and the configuration information of the n dedicated RA subchannels to UEs in a cell through a broadcast message.

The broadcast message also carries state information, and the state information is used for informing the UE of performing random access in the cell by using a PRACH sub-channel division mode.

Wherein, the state information occupies the expanded 1 bit.

In another embodiment, when the method is applied to a random access procedure of a user in a HANDOVER situation in a wireless access system, the first sending unit is configured to send the configuration information of the m common RA subchannels and the configuration information of the n dedicated RA subchannels to a UE of the user in the HANDOVER situation in a cell through a HANDOVER COMMAND message.

In other embodiments, when the method is applied to a random access procedure of a user in a wireless access system under an out-of-synchronization condition of an air interface, the first sending unit is configured to send, through a PDCCH Order message, the configuration information of the m common RA subchannels and the configuration information of the n dedicated RA subchannels to a UE in a cell under an out-of-synchronization condition of an air interface.

In other embodiments, the first apparatus further comprises:

a first receiving unit, configured to receive a dedicated Preamble sequence sent by at least one UE on a dedicated RA subchannel and a common Preamble sequence sent on a common RA subchannel;

a determining unit, configured to determine a TA value from a correlation peak of a common RA subchannel and a correlation peak of a dedicated RA subchannel for each of the UEs having a random access collision, if the UEs having the random access collision are determined by detecting the n dedicated RA subchannels and the m common RA subchannels.

In other embodiments, the first apparatus further comprises:

a first receiving unit, configured to receive a dedicated Preamble sequence sent by at least one UE on a dedicated RA subchannel and a common Preamble sequence sent on a common RA subchannel;

a first access unit, configured to detect that only one dedicated RA subchannel is occupied by detecting the n dedicated RA subchannels, and complete a random access procedure for a corresponding UE through a common RA subchannel or the occupied dedicated RA subchannel.

In other embodiments, the determining unit includes:

a first detection module for detecting a first number p1 of said n dedicated RA sub-channels that is occupied;

a second detecting module, configured to detect a second number p2 of Preamble sequences with different index values in the m common RA subchannels;

a first determining module for determining a random access collided UE if the first number p1 is greater than the second number p 2.

In other embodiments, the method further comprises:

a first receiving unit, configured to receive a dedicated Preamble sequence sent by at least one UE on a dedicated RA subchannel and a common Preamble sequence sent on a common RA subchannel;

a first detection unit for detecting a first number p1 of said n dedicated RA sub-channels that is occupied;

a second detecting unit, configured to detect a second number p2 of Preamble sequences with different index values in the m common RA subchannels;

a second access unit for determining no access collision if the first number p1 is equal to the second number p 2; and finishing the random access process for the corresponding UE through the public RA sub-channel or the occupied special RA sub-channel.

In other embodiments, the determining unit includes: a superposition module, configured to superpose a correlation peak of a common RA subchannel and a correlation peak of a dedicated RA subchannel of each UE in the UEs having a random access collision if the UEs having the random access collision can be distinguished according to a delay of the dedicated RA subchannel and a delay of the common RA subchannel;

and the second determining module is used for determining the TA value of each UE in the UEs with random access conflicts according to the superposition value and the corresponding judgment threshold.

In other embodiments, the determining unit includes:

an averaging module, configured to average the estimation results of the correlation peak of the dedicated RA subchannel and the correlation peak of the common RA subchannel if the UE with the random access collision cannot be distinguished according to the time delay of the dedicated RA subchannel and the time delay of the common RA subchannel;

a third determining module, configured to use the average value as a TA value of each UE of the UEs with random access collision.

In other embodiments, the second receiving unit is configured to receive, through a broadcast message, the configuration information of the m common RA subchannels and the configuration information of the n dedicated RA subchannels when the UE is in a contention-based random access procedure.

In another embodiment, the second receiving unit is configured to receive, through a HANDOVER COMMAND message, the configuration information of the m common RA subchannels and the configuration information of the n dedicated RA subchannels when the UE is in a random access procedure in a HANDOVER situation.

In other embodiments, the second receiving unit is configured to receive, through a PDCCH Order message, the configuration information of the m common RA subchannels and the configuration information of the n dedicated RA subchannels when the UE is in a random access process under an out-of-synchronization condition of an air interface.

The above description of the apparatus embodiments, similar to the above description of the method embodiments, has similar beneficial effects as the method embodiments. For technical details not disclosed in the embodiments of the apparatus according to the invention, reference is made to the description of the embodiments of the method according to the invention for understanding.

It should be noted that, in the embodiment of the present invention, if the random access method is implemented in the form of a software functional module and is sold or used as a standalone product, the random access method may also be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the embodiments of the present invention may be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for enabling a random access device to perform all or part of the methods according to the embodiments of the present invention. And the aforementioned storage medium includes: various media capable of storing program codes, such as a usb disk, a removable hard disk, a Read Only Memory (ROM), a magnetic disk, or an optical disk. Thus, embodiments of the invention are not limited to any specific combination of hardware and software.

Correspondingly, an embodiment of the present invention provides a terminal, including a memory, a processor, and a computer program stored in the memory and executable on the processor, where the processor implements the steps in the random access method at the terminal side when executing the program.

Correspondingly, an embodiment of the present invention provides a base station, including a memory, a processor, and a computer program stored in the memory and executable on the processor, where the processor implements the steps in the random access method on the base station side when executing the program.

Correspondingly, an embodiment of the present invention provides a computer-readable storage medium, on which a computer program is stored, where the computer program, when executed by a processor, implements the steps in the random access method on the base station side; alternatively, the computer program realizes the steps in the random access method at the terminal side when executed by the processor.

The above description of the storage medium and device embodiments is similar to the description of the method embodiments above, with similar advantageous effects as the method embodiments. For technical details not disclosed in the embodiments of the storage medium and the apparatus according to the invention, reference is made to the description of the embodiments of the method according to the invention.

It should be noted that fig. 7 is a schematic diagram of a hardware entity of a random access device in an embodiment of the present invention, as shown in fig. 7, therandom access device 700 may be a base station or a terminal, and the hardware entity of the device includes: aprocessor 701, acommunication interface 702, and a memory 703, wherein

Theprocessor 701 generally controls the overall operation of therandom access device 700.

Thecommunication interface 702 may enable the random access device to communicate with other terminals or servers over a network.

The Memory 703 is configured to store instructions and applications executable by theprocessor 701, and may also cache data to be processed or already processed by each module in theprocessor 701 and theRandom Access device 700, and may be implemented by a FLASH Memory (FLASH) or a Random Access Memory (RAM).

It should be appreciated that reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. It should be understood that, in various embodiments of the present invention, the sequence numbers of the above-mentioned processes do not mean the execution sequence, and the execution sequence of each process should be determined by its function and inherent logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention. The above-mentioned serial numbers of the embodiments of the present invention are merely for description and do not represent the merits of the embodiments.

It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

In the several embodiments provided in the present application, it should be understood that the disclosed apparatus and method may be implemented in other ways. The above-described device embodiments are merely illustrative, for example, the division of the unit is only a logical functional division, and there may be other division ways in actual implementation, such as: multiple units or components may be combined, or may be integrated into another system, or some features may be omitted, or not implemented. In addition, the coupling, direct coupling or communication connection between the components shown or discussed may be through some interfaces, and the indirect coupling or communication connection between the devices or units may be electrical, mechanical or other forms.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units; can be located in one place or distributed on a plurality of network units; some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, all the functional units in the embodiments of the present invention may be integrated into one processing unit, or each unit may be separately regarded as one unit, or two or more units may be integrated into one unit; the integrated unit can be realized in a form of hardware, or in a form of hardware plus a software functional unit.

Those of ordinary skill in the art will understand that: all or part of the steps for realizing the method embodiments can be completed by hardware related to program instructions, the program can be stored in a computer readable storage medium, and the program executes the steps comprising the method embodiments when executed; and the aforementioned storage medium includes: various media that can store program codes, such as a removable Memory device, a Read Only Memory (ROM), a magnetic disk, or an optical disk.

Alternatively, the integrated unit of the present invention may be stored in a computer-readable storage medium if it is implemented in the form of a software functional module and sold or used as a separate product. Based on such understanding, the technical solutions of the embodiments of the present invention may be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for enabling a random access device (terminal or base station, etc.) to perform all or part of the methods described in the embodiments of the present invention. And the aforementioned storage medium includes: a removable storage device, a ROM, a magnetic or optical disk, or other various media that can store program code.

The above description is only an embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive of changes or substitutions within the technical scope of the present invention, and all such changes or substitutions are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the appended claims.

Claims (24)

1. A random access method, the method comprising:

dividing a Physical Random Access Channel (PRACH) into m public Random Access (RA) sub-channels and n special RA sub-channels; wherein, one said public RA sub-channel is used for random access of more than one terminal UE, and one said special RA sub-channel is used for random access of one UE; m and n are integers of 1 or more;

sending the configuration information of the m public RA sub-channels and the configuration information of the n special RA sub-channels to corresponding UE to complete a random access process;

receiving a dedicated Preamble sequence sent by at least one UE on a dedicated RA subchannel and a common Preamble sequence sent on a common RA subchannel;

and if the UE with random access conflict is determined by detecting the n dedicated RA sub-channels and the m common RA sub-channels, determining a TA value by the correlation peak of the common RA sub-channel and the correlation peak of the dedicated RA sub-channel of each UE in the UE with random access conflict.

2. The method of claim 1, wherein m is 1 and n is an estimated value equal to or greater than a number of UEs performing random access simultaneously in a cell.

3. The method of claim 1, wherein a guard interval is provided between each of the m common RA subchannels and the n dedicated RA subchannels.

4. The method of claim 3, wherein the RA sub-channels respectively transmit Preamble sequences generated by different ZC root sequences, the length of a common Preamble sequence is consistent with that of a corresponding common RA sub-channel, and the length of a dedicated Preamble sequence is the same as that of a corresponding dedicated RA sub-channel.

5. The method of claim 3, wherein the length of each Preamble sequence is less than or equal to the number of subcarriers occupied by the corresponding RA subchannel.

6. The method according to any of claims 1 to 5, wherein the frequency domain resources of m common RA subchannels and the frequency domain resources of n dedicated RA subchannels are statically generated when the method is applied to a contention-based random access procedure in a wireless access system;

the sending the configuration information of the m public RA subchannels and the configuration information of the n dedicated RA subchannels to the corresponding UE includes:

and sending the configuration information of the m public RA subchannels and the configuration information of the n special RA subchannels to the UE in the cell through a broadcast message.

7. The method of claim 6, wherein the broadcast message further carries status information, and the status information is used to notify the UE of performing random access in the cell by using a PRACH subchannel division manner.

8. The method of claim 6, wherein the status information occupies the extended 1 bit.

9. The method according to any of claims 1 to 5, wherein the frequency domain resources of m common RA subchannels and the frequency domain resources of n dedicated RA subchannels are generated statically or dynamically when the method is applied to a random access procedure for a user in a handover situation in a wireless access system;

the sending the configuration information of the m public RA subchannels and the configuration information of the n dedicated RA subchannels to the corresponding UE includes:

and sending the configuration information of the m public RA sub-channels and the configuration information of the n special RA sub-channels to UE of a user under the condition of switching in a cell through a HANDOVER COMMAND HANDOVER COMMAND message.

10. The method according to any of claims 1 to 5, wherein when the method is applied to a random access procedure of a user in a wireless access system under an out-of-synchronization condition of an air interface, the frequency domain resources of m public RA subchannels and the frequency domain resources of n dedicated RA subchannels are generated statically or dynamically;

the sending the configuration information of the m public RA subchannels and the configuration information of the n dedicated RA subchannels to the corresponding UE includes:

and sending the configuration information of the m public RA sub-channels and the configuration information of the n special RA sub-channels to UE under the condition of air interface desynchronization in a cell through a PDCCH Order message.

11. The method according to any one of claims 1 to 5, further comprising:

receiving a dedicated Preamble sequence sent by at least one UE on a dedicated RA subchannel and a common Preamble sequence sent on a common RA subchannel;

and detecting the n special RA sub-channels to find that only one special RA sub-channel is occupied, and finishing a random access process for the corresponding UE through the common RA sub-channel or the occupied special RA sub-channel.

12. The method of claim 1, wherein the determining the UE with random access collision by detecting the n dedicated RA subchannels and the m common RA subchannels comprises:

detecting a first number p1 of the n dedicated RA subchannels that is occupied;

detecting a second number p2 of Preamble sequences with different index values in the m public RA sub-channels;

if the first number p1 is greater than the second number p2, a random access conflicting UE is determined.

13. The method according to any one of claims 1 to 5, further comprising:

receiving a dedicated Preamble sequence sent by at least one UE on a dedicated RA subchannel and a common Preamble sequence sent on a common RA subchannel;

detecting a first number p1 of the n dedicated RA subchannels that is occupied;

detecting a second number p2 of Preamble sequences with different index values in the m public RA sub-channels;

if the first number p1 is equal to the second number p2, a random access procedure is completed for the corresponding UE through the common RA sub-channel or the occupied dedicated RA sub-channel.

14. The method of claim 1, wherein determining the TA value by using the correlation peak of the common RA sub-channel and the correlation peak of the dedicated RA sub-channel of each of the UEs with random access collision comprises:

if the UE with random access conflict can be distinguished according to the time delay of the special RA sub-channel and the time delay of the common RA sub-channel, superposing the correlation peak of the common RA sub-channel of each UE with random access conflict and the correlation peak of the special RA sub-channel;

and determining the TA value of each UE in the UEs with random access conflicts according to the superposition value and the corresponding judgment threshold.

15. The method of claim 1, wherein determining the TA value by using the correlation peak of the common RA sub-channel and the correlation peak of the dedicated RA sub-channel of each of the UEs with random access collision comprises:

if the UE with random access conflict can not be distinguished according to the time delay of the special RA sub-channel and the time delay of the public RA sub-channel, averaging the estimation results of the correlation peak of the special RA sub-channel and the correlation peak of the public RA sub-channel;

and taking the average value as the TA value of each UE in the UEs with random access collision.

16. A random access method, the method comprising:

the UE receives the configuration information of the m public RA sub-channels and the configuration information of the n special RA sub-channels sent by the base station;

UE selects a public Preamble sequence and a special Preamble sequence, and selects a public RA sub-channel and a special RA sub-channel according to the configuration information of the m public RA sub-channels and the configuration information of the n special RA sub-channels;

and the UE sends a dedicated Preamble sequence on the selected dedicated RA sub-channel and sends a common Preamble sequence on the selected common RA sub-channel.

17. The method of claim 16, further comprising:

and when the UE is in a contention-based random access process, receiving the configuration information of the m public RA sub-channels and the configuration information of the n special RA sub-channels through a broadcast message.

18. The method of claim 16, further comprising:

and when the UE is in a random access process under the condition of switching, receiving the configuration information of the m public RA sub-channels and the configuration information of the n special RA sub-channels through a HANDOVER COMMAND message.

19. The method of claim 16, further comprising:

and when the UE is in the random access process under the condition of air interface desynchronization, receiving the configuration information of the m public RA sub-channels and the configuration information of the n special RA sub-channels through a PDCCH Order message.

20. A terminal comprising a memory, a processor and a computer program stored on the memory and executable on the processor, wherein the steps of the method of any one of claims 16 to 19 are carried out when the program is executed by the processor.

21. A base station comprising a memory, a processor and a computer program stored on the memory and executable on the processor, wherein the processor implements the steps of the method of any one of claims 1 to 15 when executing the program.

22. A computer-readable storage medium, on which a computer program is stored which, when being executed by a processor, carries out the steps of the method of any one of claims 1 to 15; alternatively, the computer program realizes the steps of the method of claims 16 to 19 when executed by a processor.

23. A random access apparatus, the apparatus comprising:

a dividing unit, configured to divide a PRACH channel into m public RA subchannels and n dedicated RA subchannels; wherein one said common RA sub-channel is used for random access of more than one UE, and one said dedicated RA sub-channel is used for random access of one UE;

a first sending unit, configured to send the configuration information of the m public RA subchannels and the configuration information of the n dedicated RA subchannels to corresponding UEs to complete a random access procedure;

a first receiving unit, configured to receive a dedicated Preamble sequence sent by at least one UE on a dedicated RA subchannel and a common Preamble sequence sent on a common RA subchannel;

a determining unit, configured to determine a TA value from a correlation peak of a common RA subchannel and a correlation peak of a dedicated RA subchannel for each of the UEs having a random access collision, if the UEs having the random access collision are determined by detecting the n dedicated RA subchannels and the m common RA subchannels.

24. A random access apparatus, the apparatus comprising:

a second receiving unit, configured to receive configuration information of the m public RA subchannels and configuration information of the n dedicated RA subchannels sent by a base station;

a selecting unit, configured to select a common Preamble sequence and a dedicated Preamble sequence, and select a common RA subchannel and a dedicated RA subchannel according to the configuration information of the m common RA subchannels and the configuration information of the n dedicated RA subchannels;

and a second sending unit, configured to send a dedicated Preamble sequence on the selected dedicated RA subchannel, and send a common Preamble sequence on the selected common RA subchannel.

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