CN106803782B

Movatterモバイル変換

Info

Publication number: CN106803782B
Application number: CN201510843406.0A
Authority: CN
Inventors: 张孝中; 刘燕武; 李荣泽
Original assignee: ZTE Corp
Current assignee: ZTE Corp
Priority date: 2015-11-26
Filing date: 2015-11-26
Publication date: 2020-05-29
Anticipated expiration: 2035-11-26
Also published as: JP2019503116A; CN106803782A; WO2017088515A1

Abstract

A channel rank reduction method and apparatus for a massive antenna system, the method comprising: correcting and detecting a channel of an antenna, and judging whether the channel has a fault according to a detection result; and performing channel rank reduction according to the judgment result of whether the channel has faults. The device comprises: the detection and judgment module is used for carrying out correction detection on the channel of the antenna and judging whether the channel has a fault according to a detection result; and the rank reduction processing module is used for performing channel rank reduction processing according to the judgment result of whether the channel has faults. By using the channel rank reduction method and device, when part of antennas are damaged, the fault channel can be accurately positioned, rank reduction processing is performed on the fault channel, negative effects of antenna damage are made up, and reliability and stability of a large-scale antenna system are improved.

Description

Channel rank reduction method and device for large-scale antenna system

Technical Field

The present invention relates to communication technologies, and in particular, to a channel rank reduction method and apparatus for a large-scale antenna system.

Background

In a large-scale (Massive) Multiple-Input Multiple-Output (MIMO) antenna system, due to the fact that the number of designed channels is large, 64 channels, 128 channels and even 256 channels are designed. During the operation of commercial post-outfield systems, it is difficult to avoid the failure of individual channels. It is necessary to avoid the adverse effect of some or several channel faults on the overall function and performance of the system, and to provide a method capable of ensuring the normal operation of the system.

In a Massive MIMO multi-antenna system, a Beam Forming (BF) technology is mainly utilized, and beam forming is carried out on a multi-antenna array, so that air interface channels tend to be orthogonal, and a spatial channel matrix forms more ranks, so that more user streams are obtained, and the throughput of the system is improved. The improvement of Massive MIMO system throughput mainly depends on the construction of orthogonal spatial correlation matrix, and in the technical evolution of Pre 5G, there are two modes of Time Division Duplexing (TDD) and Frequency Division Duplexing (FDD). The TDD mainly obtains a multi-stream spatial channel matrix by utilizing the reciprocity of an uplink channel and a downlink channel on the basis of an intelligent antenna technology; while FDD may be an extension of the conventional MIMO technology, and a spatial precoding matrix is used to improve the system throughput.

It can be seen that the TDD system has natural advantages in a Massive MIMO system, and when the number of antennas of a base station increases continuously, downlink reciprocity is used, uplink signals received in reverse direction of each channel are used, downlink channel characteristics are obtained through uplink channel estimation and back-stepping, and then a downlink beamforming weight is obtained through spatial matrix calculation.

If partial antenna failure or damage occurs in a Massive MIMO antenna system, the spatial matrix of multiple antennas will be destroyed, the channel matrix between multiple users may no longer be orthogonal, the mutual interference between multiple users becomes prominent, and the system performance deteriorates. This is mainly expressed in that for a common user, i.e. a user not performing beamforming, its uplink and downlink channels are independent, and if there is channel damage, interference may be added to the uplink and downlink channels; for space division users, that is, users of beamforming, the damage of the radio frequency channel not only affects the performance of downlink beamforming, but also destroys the matrix of the downlink spatial channel, and the multiple users are no longer orthogonal, and may even interfere with each other, so that the performance of downlink space division is worsened.

Therefore, there is a need to provide a method for avoiding severe system performance deterioration and enabling the base station to still operate normally when a large-scale antenna system has a part of antennas damaged.

Disclosure of Invention

In view of the above, the present invention provides the following technical solutions.

A channel rank reduction method of a large-scale antenna system comprises the following steps:

correcting and detecting a channel of an antenna, and judging whether the channel has a fault according to a detection result;

and performing channel rank reduction according to the judgment result of whether the channel has faults.

Alternatively,

the method for correcting and detecting the channel of the antenna and judging whether the channel has faults or not according to the detection result comprises the following steps:

and carrying out correction detection on the channel of the antenna for multiple times, judging whether the channel has faults or not according to the detection result of each time, if the judgment result of each time indicates that the channel has faults, determining that the channel has faults, and otherwise, determining that the channel does not have faults.

Alternatively,

the judging whether the channel has a fault according to each detection result comprises the following steps:

and judging whether the channel has faults or not according to one or more of the power, the signal-to-noise ratio and the amplitude range of the channel detected each time.

Alternatively,

judging whether the channel is a fault channel according to one or more of the power, the signal-to-noise ratio and the frequency range of the channel, including:

if one channel meets any one of the following conditions, judging that the channel has a fault, otherwise, judging that the channel does not have the fault:

the first condition is as follows: the difference between the power of the channel and the average power of all the channels is smaller than the corresponding power threshold;

and a second condition: the signal-to-noise ratio of the channel is less than the corresponding signal-to-noise ratio threshold;

and (3) carrying out a third condition: the amplitude range of the channel within the output frequency band is greater than the corresponding amplitude range threshold.

Alternatively,

if a reference channel meets any one of the first condition, the second condition and the third condition, judging that the reference channel has a fault, otherwise, judging that the reference channel does not have the fault;

if a common channel meets any one of the first condition and the second condition, judging that the common channel has a fault, otherwise, judging that the common channel does not have the fault.

Alternatively,

and performing channel rank reduction according to the judgment result of whether the channel has faults, wherein the channel rank reduction comprises the following steps:

if the reference channel has no fault, the reference channel is not subjected to rank reduction treatment;

if the reference channel has faults and the alternative reference channel has no faults, taking the alternative reference channel without faults as a new reference channel and not performing rank reduction processing on the reference channel;

if the reference channel and all the alternative reference channels have faults, reducing the rank of the reference channel, wherein the reducing the rank of the reference channel comprises the following steps: and closing the uplink channel and/or the downlink channel with faults in the reference channel, and closing the beam forming function of the large-scale antenna system.

Alternatively,

if the reference channels in the two directions do not have faults, the rank reduction of the reference channels is not carried out;

if the reference channel in at least one direction has faults and all the alternative reference channels in the direction have faults, reducing the rank of the reference channel;

if the reference channel in at least one direction has faults and the alternative reference channels in each direction with the faults of the reference channel have no faults, taking the alternative reference channel without the faults in each direction as a new reference channel in the direction without reducing the rank of the reference channel;

wherein the two directions refer to an uplink direction and a downlink direction, and the reference channel rank reduction comprises: and closing the uplink channel and/or the downlink channel with faults in the reference channel, and closing the beam forming function of the large-scale antenna system.

Alternatively,

the channel rank reduction processing according to the judgment result of whether the channel has faults comprises the following steps:

and for each common channel with the fault, closing the uplink channel and the downlink channel of the common channel.

Alternatively,

for each common channel with a fault:

when the common channel is used for the beamforming service, closing an uplink channel and a downlink channel of the common channel;

and when the common channel is not used for the beamforming service, if the uplink channel of the common channel fails, closing the uplink channel, and if the downlink channel of the common channel fails, closing the downlink channel of the common channel.

Alternatively,

the upward channel for closing the common channel comprises: setting the uplink antenna correction weight of the common channel to 0;

the downstream channel for closing the common channel includes: and setting the downlink antenna correction weight value of the common channel to be 0.

Alternatively,

after judging whether the channel has a fault, the method further comprises the following steps: counting the number of channels with faults;

firstly, judging whether the number is greater than or equal to a corresponding number threshold;

if yes, the beam forming function of the large-scale antenna system is closed, and the uplink channel and the downlink channel with faults are closed;

if not, respectively performing rank reduction processing on the reference channel and the common channel.

A channel rank reduction apparatus of a massive antenna system, comprising:

the detection and judgment module is used for carrying out correction detection on the channel of the antenna and judging whether the channel has a fault according to a detection result;

and the rank reduction processing module is used for performing channel rank reduction processing according to the judgment result of whether the channel has faults.

Alternatively,

the detection and judgment module corrects and detects the channel of the antenna and judges whether the channel has faults according to the detection result, and the method comprises the following steps: and carrying out correction detection on the channel of the antenna for multiple times, judging whether the channel has faults or not according to the detection result of each time, if the judgment result of each time indicates that the channel has faults, determining that the channel has faults, and otherwise, determining that the channel does not have faults.

Alternatively,

the detecting and judging module judges whether the channel has a fault according to each detection result, and the detecting and judging module comprises: and judging whether the channel has faults or not according to one or more of the power, the signal-to-noise ratio and the amplitude range of the channel detected each time.

Alternatively,

the detecting and judging module judges whether the channel is a fault channel according to one or more of the power, the signal-to-noise ratio and the frequency range of the channel, and comprises the following steps: if one channel meets any one of the following conditions, judging that the channel has a fault, otherwise, judging that the channel does not have the fault:

Alternatively,

the detecting and judging module judges whether the channel is a fault channel according to one or more of the power, the signal-to-noise ratio and the frequency range of the channel, and comprises the following steps:

Alternatively,

the rank reduction processing module performs channel rank reduction processing according to the judgment result of whether the channel has faults, and the processing method comprises the following steps:

if the reference channel and all the alternative reference channels have faults, informing the rank reduction processing module to reduce the rank of the reference channel;

the rank reduction processing module performs reference channel rank reduction, and comprises: and closing the uplink channel and/or the downlink channel with faults in the reference channel, and closing the beam forming function of the large-scale antenna system.

Alternatively,

if the reference channel in at least one direction has faults and all the alternative reference channels in the direction have faults, informing the rank reduction processing module to reduce the rank of the reference channel;

Alternatively,

the rank reduction processing module performs channel rank reduction processing according to the judgment result of whether the channel has faults, and the processing method comprises the following steps: and for each common channel with the fault, closing the uplink channel and the downlink channel of the common channel.

Alternatively,

the rank reduction processing module performs channel rank reduction processing according to the judgment result of whether the channel has faults, and the processing method comprises the following steps: for each common channel with a fault: when the common channel is used for the beamforming service, closing an uplink channel and a downlink channel of the common channel; and when the common channel is not used for the beamforming service, if the uplink channel of the common channel fails, closing the uplink channel, and if the downlink channel of the common channel fails, closing the downlink channel of the common channel.

Alternatively,

the step of closing the uplink channel of the common channel by the rank reduction processing module comprises the following steps: setting the uplink antenna correction weight of the common channel to 0; the step of closing the downlink channel of the common channel by the rank reduction processing module comprises the following steps: and setting the downlink antenna correction weight value of the common channel to be 0.

Alternatively,

the detection judging module is also used for counting the number of the channels with faults;

the rank reduction processing module performs channel rank reduction processing according to the judgment result of whether the channel has faults, and the processing method comprises the following steps: firstly, judging whether the number is greater than or equal to a corresponding number threshold: if yes, the beam forming function of the large-scale antenna system is closed, and the uplink channel and the downlink channel with faults are closed; if not, respectively performing rank reduction processing on the reference channel and the common channel.

According to the channel rank reduction method and device for the large-scale antenna system, when partial antennas are damaged, the fault channel can be accurately positioned, rank reduction processing is performed on the fault channel, negative effects of antenna damage are made up, and reliability and stability of the large-scale antenna system are improved.

Drawings

FIG. 1 is a flow chart of a channel rank reduction method according to an embodiment of the present invention;

FIG. 2 is a block diagram of a channel rank reduction apparatus according to an embodiment of the present invention;

FIG. 3 is a mapping diagram of a 64 antenna system according to an exemplary embodiment of the present invention;

FIG. 4 is a flow chart illustrating an exemplary lane failure determination of the present invention;

FIG. 5 is a flow diagram illustrating an example of a reference channel de-ranking process of the present invention;

FIG. 6 is a flow diagram illustrating an example of a common channel rank reduction process;

FIG. 7 is a flow diagram illustrating an exemplary two reference channel rank reduction process of the present invention;

fig. 8 is a diagram illustrating an example four common channel joint rank reduction of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that the embodiments and features of the embodiments in the present application may be arbitrarily combined with each other without conflict.

Example one

The large-scale antenna system of this embodiment is exemplified by a Massive MIMO system of TDD. As shown in fig. 1, the channel rank reduction method of the large-scale antenna system of the embodiment includes:

step 110, performing correction detection on a channel of an antenna, and judging whether the channel has a fault according to a detection result;

and 120, performing channel rank reduction according to the judgment result of whether the channel has faults.

In order to keep the amplitude and phase consistent among the antenna channels in a large-scale antenna system, antenna correction is needed. Without antenna calibration, the performance of beamforming is affected and the ideal beamforming effect is not achieved. In the correction process, correction detection is needed, and channel calibration is carried out according to the detection result. If the detection result indicates that the channel is damaged, the channel rank reduction processing is performed according to the judgment result of whether the channel has a fault.

The antenna herein includes a physical antenna and a corresponding radio frequency channel (referred to as a channel for short), and a channel corresponding to a physical antenna includes an uplink channel and a downlink channel. Taking a large-scale antenna system arranged in a base station as an example, the receiving direction of the base station is an uplink direction, and an uplink channel is a radio frequency receiving channel of the base station; the base station transmitting direction is a downlink direction, and a downlink channel is a radio frequency transmitting channel of the base station.

In this context, from the perspective of antenna calibration, the channels of the antenna in the large-scale antenna system are divided into a reference channel and a common channel, the reference channel is a basis for calibrating other channels, and the channels except the reference channel are common channels. The reference channel can be divided into an uplink reference channel and a downlink reference channel, which are used as the basis for uplink calibration and downlink calibration of other channels, respectively. A special channel in the common channels is called an alternative reference channel, and the set of alternative reference channels can be called an alternative reference channel pool.

Herein, as not more specifically defined and specifically explained, the correction detection of one channel (including the reference channel and the normal channel), including the correction detection of the upstream channel and the downstream channel of the channel, determines whether the channel has a fault, including determining whether the upstream channel and the downstream channel of the channel have a fault. If not stated otherwise, a failure is detected in at least one of the upstream and downstream lanes of a lane, i.e., the lane is considered to have a failure.

In thestep 110, the channel of the antenna is corrected and detected, when it is determined whether the channel has a fault according to the detection result, in order to obtain more sample data, improve the accuracy of the channel fault determination module, and avoid misdetermination caused by some abnormality or emergency, in this embodiment, the channel of the antenna is corrected and detected for multiple times, and whether the channel has a fault is determined according to the detection result of each time, if the channel has a fault according to each determination, it is determined that the channel has a fault, otherwise, it is determined that the channel has no fault. The number of corrections is not limited by the present invention.

At each correction, it can be determined whether the channel has a fault according to one or more of the power, signal-to-noise ratio and amplitude range of the channel, but not limited to.

Specifically, the following judgment conditions may be adopted:

if a channel meets any one of the following one or more conditions (any one includes multiple conditions), judging that the channel has a fault, otherwise, judging that the channel does not have the fault:

The first condition is judgment according to a power calibration criterion, and the second condition is judgment according to a signal-to-noise ratio criterion. In this embodiment, in consideration of the difference between the reference channel and the normal channel, the criterion of the third condition, i.e., the channel flatness criterion, is added to the reference channel. Specifically, if a reference channel meets any one of the first condition, the second condition and the third condition, judging that the reference channel has a fault, otherwise, judging that the reference channel does not have the fault; if a common channel meets any one of the first condition and the second condition, judging that the common channel has a fault, otherwise, judging that the common channel does not have the fault.

In thestep 120, when performing the channel rank reduction processing according to the judgment result of whether the channel has the fault, the rank reduction processing is divided into the rank reduction processing for the reference channel and the rank reduction processing for the common channel.

When the reference channel fails, a new reference channel can be selected from the candidate reference channels without the failure, and the original reference channel is no longer used as the reference channel for channel calibration.

Specifically, the rank reduction processing on the reference channel includes:

if the reference channel and all the alternative reference channels have faults, reducing the rank of the reference channel; wherein the reference channel rank reduction comprises: and closing the uplink channel and/or the downlink channel with faults in the reference channel, and closing the beam forming function of the large-scale antenna system. After the beamforming function of the large-scale antenna system is turned off, the channel in the direction where the reference channel has no fault may not be turned off.

In terms of channel calibration, if there is no fault in the reference channel or a new reference channel is selected, the calibration of the normal channel can be continued. If the reference channel and all the alternative reference channels have faults, the normal channel is not calibrated. However, the normal channel with the fault can still be subjected to the rank reduction processing. And when the alternative reference channel is not selected as the reference channel, performing rank reduction according to the common channel. After a new reference channel is selected, the reference channel with the fault can be used as a common channel for rank reduction.

The Massive MIMO system of TDD needs to consider reciprocity of an uplink channel and a downlink channel in the same channel, and the uplink reference channel and the downlink reference channel need to be in one reference channel.

Specifically, there are two ways for the rank reduction processing of the common channel:

first, for each normal channel with a failure, the upstream channel and the downstream channel of the normal channel are closed.

The method is simple, and the uplink channel and the downlink channel of the common channel are closed no matter the common channel with the fault is the uplink channel fault, or the downlink channel fault, or both the uplink channel and the downlink channel have the fault, so that the common channel does not participate in data transmission and beam forming any more.

Secondly, for each common channel with faults, when the common channel is used for beamforming service (such as being allocated to an air separation user), closing an uplink channel and a downlink channel of the common channel without distinguishing the uplink channel fault and the downlink channel fault; when the normal channel is not used for beamforming service (for example, the normal channel is allocated to a non-space division user, or the beamforming function of the whole system is turned off), the uplink channel fault and the downlink channel fault are respectively subjected to rank reduction, that is, the uplink channel of the normal channel is turned off if the uplink channel of the normal channel is faulty, and the downlink channel of the normal channel is turned off if the downlink channel of the normal channel is faulty.

In this way, when the common channel is not used for beamforming service, if there is only channel failure in one direction, the channel in the other direction can also be used. However, the adjustment needs to be performed in real time according to whether the common channel is used for the beamforming service, and the processing is relatively complex.

In this embodiment, the closing the uplink channel of the common channel includes: setting the uplink antenna correction weight of the common channel to 0; the downstream channel for closing the common channel includes: and setting the downlink antenna correction weight value of the common channel to be 0. However, other ways of closing the passage may be used in the present invention.

The present embodiment further provides a channel rank reduction apparatus for a large-scale antenna system, as shown in fig. 2, including:

the detection andjudgment module 10 is used for performing correction detection on the channel of the antenna and judging whether the channel has a fault according to a detection result;

and the rankreduction processing module 20 is configured to perform rank reduction processing on the channel according to a determination result of whether the channel has a fault.

Alternatively,

Example two

The large-scale antenna system of this embodiment is exemplified by a Massive MIMO system of FDD. The present embodiment is basically the same as the channel rank reduction method in the first embodiment, except that channel reciprocity does not need to be considered in an FDD system, so that when performing rank reduction processing on a reference channel, an uplink reference channel and a downlink reference channel may be respectively processed, specifically:

in this embodiment, performing channel rank reduction processing according to a determination result of whether a channel has a fault includes:

wherein, the two directions refer to an uplink direction and a downlink direction, and the reference channel rank reduction mode comprises: and closing the uplink channel and/or the downlink channel with faults in the reference channel, and closing the beam forming function of the large-scale antenna system.

the present embodiment of the present invention provides a method for performing channel rank reduction processing by a rank reduction processing module according to a determination result of whether a channel has a fault, including:

EXAMPLE III

The large-scale antenna system of this embodiment may be a Massive MIMO system of FDD or TDD. The channel rank reduction method of the embodiment adds the processing of counting the number of the fault channels on the basis of the two-channel rank reduction method of the embodiment one or the embodiment two, and adopts a rank reduction processing mode when the number of the fault channels is too large, and adopts the rank reduction processing mode of the embodiment one or the embodiment two when the number of the fault channels is not too large.

Specifically, after determining whether the channel has a fault, the present embodiment counts the number of channels having a fault; and the channel rank reduction treatment is carried out according to the judgment result of whether the channel has faults, and the method comprises the following steps: firstly, judging whether the number is greater than or equal to a corresponding number threshold;

if so, closing the beamforming function of the large-scale antenna system, and closing the uplink channel and the downlink channel with faults (at this time, the closing of the uplink channel and the closing of the downlink channel are also processed respectively);

if not, performing rank reduction processing on the reference channel and the common channel respectively, and adopting a rank reduction processing mode in the first embodiment or the second embodiment.

Correspondingly, the detection and judgment module in the channel rank reduction device of the embodiment is further used for counting the number of channels with faults; and the rank reduction processing module performs channel rank reduction processing according to the judgment result of whether the channel has faults, and the processing method comprises the following steps: firstly, judging whether the number is greater than or equal to a corresponding number threshold: if yes, the beam forming function of the large-scale antenna system is closed, and the uplink channel and the downlink channel with faults are closed; if not, respectively performing rank reduction processing on the reference channel and the common channel.

The following is further described by way of examples in several applications.

Example 1

The present example uses the inter-channel differences and the received signals of the channels to determine whether a channel is corrupted. Whether the channel is a faulty channel can be determined by combining a power criterion, a signal-to-noise ratio criterion, a channel flatness criterion, and the like, but the method is not limited thereto. The present example distinguishes between different channels and different functions for rank reduction.

As shown in fig. 3, the large-scale antenna system of this example has 64 antennas, and the antennas are arranged and numbered regularly, and the 64 antennas include antennas with two polarization directions.

In the design of antenna calibration, it is assumed that channel 0 is a default reference channel for uplink and downlink calibration, and simultaneously, according to the order of antenna arrangement and the relative position relationship in practical application,

channels

16, 32 and 48 are selected as standby reference channels, and these reference channels constitute a reference channel pool (the selection of reference channels depends on the antenna arrangement and the radio frequency complete machine model, and the selection of reference channels may be different for different radio frequency complete machines, and the reference channel pool is generally made into an entire table and stored in system equipment). And the other channels use the reference channel as a reference during correction, and the amplitude-phase characteristics of the other channels are consistent with those of the reference channel after correction.

In the channel rank reduction method of the large-scale antenna system of the present example, the process of determining whether the channel has a fault is as follows, and fig. 4 can be seen:

this example uses different judgment methods for the reference channel and the normal channel. As an example, for the reference channel, the failure judgment is performed based on the following

criteria

1, 2, and 3, and for the normal channel, the failure judgment is performed based on the

criteria

1 and 2. .

Judgment based on criterion 1:

and calculating the difference between the power of each channel and the average power of all channels according to the antenna data received by the correction detection, if the difference is smaller than a corresponding power threshold value DeltaP1, considering that the signal received by the channel is too weak and is possibly noise or a signal leaked from other channels, and judging that the channel does not meet the power calibration criterion, otherwise, judging that the channel meets the power calibration criterion.

For example: a total of 3 channels, wherein the received power of 2 channels is 15, and the received power of 1 channel is 2; the average power of all channels is 10.6 assuming DeltaP1 is set to-3. Then the difference between the power of the 2 channels with the power of 15 and the average power of all the channels is 4.4, which is greater than the threshold-3, and the 2 channels are judged to meet the power calibration criterion; and the difference between the power of the channel with the power of 2 and the average power of all the channels is-8.6, and if the difference is less than the threshold of-3, the channel is judged not to meet the power calibration criterion.

Judgment based on criterion 2:

and estimating the signal-to-noise ratio of each channel according to the antenna data received by correction detection, if the signal-to-noise ratio of a certain channel is smaller than the corresponding threshold value SNR1, judging that the channel does not meet the signal-to-noise ratio criterion, and if not, judging that the channel meets the signal-to-noise ratio criterion.

Judgment based on criterion 3:

according to the antenna data received by correction detection, the amplitude of the channel in the output frequency band is calculated, whether the amplitude range (namely the difference between the maximum amplitude value and the minimum amplitude value) of the channel in the output frequency band is smaller than a set amplitude range threshold value DeltaA or not is judged, if yes, the channel is judged to meet the channel flatness criterion, and if not, the channel is judged not to meet the channel flatness criterion.

For a reference channel, if the reference channel does not satisfy any one of the above 3 criteria (including not satisfying multiple ones at the same time), the reference channel is determined to be a failed channel. For a common channel, if the common channel does not meet any one of the

criteria

1 and 2, the common channel is determined to be a fault channel.

It should be noted that, the power, the signal-to-noise ratio, and the amplitude range of the uplink channel and the downlink channel in one channel (including the reference channel and the normal channel) may be different, so when the above criteria are applied to determine whether the reference channel and the normal channel have a fault, the uplink channel or the downlink channel therein is determined separately. If there is a failure in at least one of the upstream and downstream lanes of a lane, the lane is considered to have a failure, unless otherwise specified.

For a channel with a fault, a corresponding bit (bit) may be set to False on the antenna bitmap, which indicates that the channel has a fault or fails. There may be 2 antenna bitmaps, one for indicating whether each uplink channel is faulty, and the other for indicating whether each downlink channel is faulty.

In this example, channel rank reduction processing is performed according to a determination result of whether the channel has a fault, and includes reference channel rank reduction processing and normal channel rank reduction processing.

The rank reduction process for the reference channel can be seen in fig. 5, which includes:

if the reference channel has no fault, the rank reduction processing of the reference channel is not carried out, and the process is finished;

if the reference channel has a fault, judging whether an undetermined alternative reference channel exists in the alternative reference channel pool:

if not, indicating that the reference channel and all the alternative reference channels have faults, performing rank reduction processing on the reference channel, and ending; the rank reduction processing of the reference channel comprises: and closing the uplink channel and/or the downlink channel with faults in the reference channel, and closing the functions related to beam forming of the system.

If yes, selecting one alternative reference channel from the alternative reference channels which are not judged by the alternative reference channel pool to carry out fault judgment:

if the alternative reference channel has no fault, taking the alternative reference channel as a new reference channel, not performing reference channel rank reduction processing, and ending;

and if the alternative reference channel has faults, returning to the step of judging whether the alternative reference channel which is not judged still exists in the alternative reference channel pool or not.

For rank reduction processing on a normal channel, see fig. 6, in this example, for a normal channel with a fault, it is first determined whether the normal channel is used for beamforming service:

if yes, performing rank reduction processing on the uplink channel and the downlink channel independently, namely: if the uplink channel fails, reducing the rank of the uplink channel independently; and if the downlink channel fails, the downlink channel is singly reduced in rank.

If not, the uplink channel and the downlink channel are subjected to combined rank reduction, namely, the rank reduction is carried out on the corresponding uplink channel and the corresponding downlink channel as long as one fault exists in the uplink channel and the downlink channel. The above-mentioned rank reduction for the channel in a certain direction may be to turn off the channel in the direction, for example, to set the Antenna calibration weight (AC) of the channel in the direction to 0.

Example two

The present example illustrates reference channel rank reduction based on the 64-antenna system in example one (fig. 3).

The rank reduction steps for the reference channel of this example are:

the first step is as follows: judging whether the default reference channel 0 is invalid or not according to the data received by the antenna correction detection, if so, turning to the second step, and if not, turning to the third step;

the second step is that: the rank reduction processing of the reference channel is not carried out, the correction of other channels is continued, and the process is finished;

the third step: selecting an undetermined standby reference channel from the reference channel pool, and if the standby reference channel is selected, switching to the fourth step, otherwise, switching to the sixth step when all the standby reference channels fail;

the order of the alternate reference channel selected isalternate reference channel 16,alternate reference channel 32, and finallyalternate reference channel 48.

Fourthly, judging whether the alternative reference channel has faults or not, and returning to the third step if the alternative reference channel has faults; if no fault exists, switching to the fifth step;

the fifth step: ending the rank reduction processing of the reference channel, selecting the standby reference channel as the reference channel for subsequent antenna correction calculation, continuing the correction of other channels, and ending;

and sixthly, performing rank reduction treatment on the reference channel.

In the first step, the present example performs 16 times of correction detection and determination, and if the reference channel 0 is determined to be faulty 16 times, it is determined that the reference channel 0 is faulty. In the process of determining whether the reference channel is faulty, 3 conditions in the first embodiment need to be determined, and as an example, the threshold may be taken as follows:

the power threshold DeltaP1 of the condition one is-5 db;

the signal-to-noise ratio threshold SNR1 of condition two is 20 DB;

the channel flatness threshold DeltaA of the condition three is 1 DB;

in this example, uplink and downlink access is independent, no uplink and downlink association is required, and channel reciprocity is not required. The rank reduction process for reference channel failure distinguishes between uplink reference channel and downlink reference channel, as can be seen in fig. 7.

Firstly, correction detection and fault judgment are carried out on the uplink reference channel and the alternative uplink reference channels, and if the uplink reference channel and all the alternative uplink reference channels have faults, the rank reduction of the reference channels is carried out. Otherwise, performing correction detection and fault judgment on the downlink reference channel and all the alternative downlink reference channels, if the uplink reference channel and all the alternative uplink reference channels have faults, reducing the rank of the reference channel, and otherwise, storing the correction weights of the uplink reference channel and the downlink reference channel. And continuing subsequent processing.

According to the above procedure, if the 64-antenna system shown in fig. 3 fails in the uplink and/or downlink channels of channel 0,channel 16,channel 32 andchannel 48, the beamforming function of the large-scale antenna system is turned off, and at this time, the base station cannot use beamforming in TM7 or TM8 mode. However, even if the base station cannot perform beamforming related application, the base station may still perform normal Lte mode operations such as TM2 and TM3, and the base station cell may still continue normal services.

Example three

This example relates to rank reduction processing for common channels not used for beamformed traffic, including:

the first step is as follows: respectively carrying out correction detection on an uplink channel and a downlink channel according to the uplink correction flow and the downlink correction flow;

the second step is that: carrying out fault judgment on an uplink channel and a downlink channel;

the third step: and performing rank reduction processing on the uplink channel and the downlink channel with faults.

Wherein the correction detection and judgment are performed for the common channel, and the correction detection and judgment are also performed 16 times. If the channel is judged to be fault through 16 times of correction detection and judgment, the channel is judged to have fault. .

In the process of judging whether the common channel is faulty, the 2 criteria of the first embodiment are used, wherein the threshold can be valued in the following manner:

the power threshold DeltaP2 of the condition one is-10 db;

the SIGNAL-to-NOISE RATIO (SNR) threshold SNR2 of the condition two is 15 DB;

if the common channel is judged to be in fault, the users distributed to the common channel need to be distinguished to carry out different rank reduction processing. Because the uplink and downlink antennas reduce the rank, the performance of the beamforming user is directly influenced.

If the common channel is allocated to the user without beamforming, the rank reduction processing of the uplink channel and the downlink channel is independent and not related to each other, as follows:

if the uplink channel is in fault, setting the antenna correction weight of the uplink channel to be 0;

and if the downlink channel is in fault, setting the antenna correction weight of the downlink channel to be 0.

Therefore, if only the uplink channel fails, the downlink of the base station cannot be influenced, and the broadcast coverage of the downlink 64 antennas and the downlink power transmission of the 64 antennas can be ensured in the downlink direction of the base station; if only the downlink channel fails, the uplink of the base station is not affected. In the uplink direction of the base station, the base station can receive the combined gain of 64 antennas of the user, and the uplink receiving performance of the base station is ensured.

Example four

The present example relates to rank reduction processing for common channels of beamformed traffic.

For space division users, that is, users needing beamforming, the rank reduction processing needs special consideration. In the example, Massive MIMO of a TDD system is taken as an example, and Massive MIO of TDD mainly obtains more channel information of users through a large number of receiving antennas by utilizing spatial uplink and downlink reciprocity, so that more users can perform space division multiplexing, the uplink and downlink throughput of a base station is improved, and the commercial value of Massive MIMO is realized.

The judgment of the common channel fault in this example is the same as that in the third example, but the processing of the uplink and downlink channel faults is different, and can be seen in fig. 8:

setting the uplink antenna correction weight and the downlink antenna correction weight of a common channel to be 0 when the uplink channel of the channel fails;

setting the correction weight of a downlink antenna and the correction weight of an uplink antenna of a common channel to be 0 when the downlink channel of the common channel fails;

example 1: and judging the uplink channel fault of thechannel 2 according to the uplink correction processing, wherein the uplink correction weight of thechannel 2 needs to be set to be 0 at the moment. The downlink channel ofchannel 2 is normal, and the corresponding downlink antenna correction weight is calculated.

However, due to the failure of the uplink channel of thechannel 2, the uplink antenna calibration weight is set to 0, and then the data received by thechannel 2 is invalid data, and the air interface information received by the corresponding channel cannot be obtained. In the embodiment, the SRS is used for calculating the channel estimation, and the channel estimation of thechannel 2 is all 0; according to the reciprocity of the uplink and downlink channels, the uplink can only obtain the new information of 63 channels, and the downlink only has the beamforming weight of 63 channels.

At this time, the downlink channel of thechannel 2 should not send data signals, otherwise, the beamforming direction is damaged, and the beamforming performance is deteriorated. When the space division is carried out by multiple users, the orthogonality among the multiple users is damaged, and the performance is more seriously reduced. Therefore, in this case, the antenna rank reduction also needs to set the downlink antenna calibration weight ofchannel 2 to 0, which is equivalent to turning off the downlink channel ofchannel 2.

Example 2: and if the downlink channel of thechannel 60 fails, setting the correction weight of the downlink antenna of thechannel 60 to 0. If the uplink channel of thechannel 60 is normal, the uplink antenna calibration weights of thechannel 60 are obtained.

If the uplink antenna calibration weight of thechannel 60 is not set to 0, the uplink channel of thechannel 60 is not turned off. When calculating the downlink beamforming weight by using the uplink channel estimation, the weight calculation is performed according to the antenna matrix of 64 antennas, and when the downlink of the antenna is actually beamformed, only 64 antennas transmit signals together according to the corresponding beamforming weight, and the downlink is the correct and expected directional direction. And if the downlink channel of thechannel 60 is faulty, the correction weight of the downlink antenna is set to 0, and the beam corresponding to the antenna cannot be sent, so that the beam forming direction of the other 63 antennas deviates from the originally expected direction when the antennas are transmitted over the air interface, and the beam forming effect cannot be achieved.

Therefore, in this case, the uplink antenna calibration weight of thechannel 60 needs to be set to 0, uplink channel estimation is obtained through 63 receiving channels in uplink, and then the channel estimation of the 63 channels is used to calculate the downlink beamforming weight, so that the downlink beamforming can achieve the desired effect.

Example four

This example relates to rank reduction processing when the number of damaged channels is up to a certain number in a large-scale (massive) antenna.

In this example, the faulty channel is determined by antenna calibration and detection, and then the number of faulty antennas is determined, and corresponding rank reduction processing is performed, including:

selecting all the reference channels and the alternative reference channels with faults through antenna correction detection and judgment, counting the number of the reference channels and recording the number as M;

selecting all the failed common channels through antenna correction detection and judgment, and counting the data and recording the data as N;

if the number of faulty antennas M + N does not reach the corresponding number threshold T, i.e., M + N < T, the rank reduction processing is performed on the reference channel and the normal channel respectively as described in the third example above;

if the number of the failed antennas M + N reaches the threshold T of the number of the damaged antennas, namely M + N is larger than or equal to T, the number of the damaged antennas is considered to be excessive, the array antenna model of Massive MIMO is damaged, the beam forming function of the large-scale antennas is closed at the moment, the base station is only enabled to operate in other normal Lte modes such as TM2 and TM3, and the conventional service of the base station is ensured. Meanwhile, for the channel with the fault, the damage of the upper and lower channels is distinguished, and the single rank reduction treatment is carried out, namely:

when the uplink channel of the channel fails, setting the uplink antenna correction weight of the channel to 0, namely performing uplink channel rank reduction;

and when the downlink channel of the channel fails, setting the downlink antenna correction weight of the channel to be 0, namely performing downlink channel rank reduction.

In this embodiment, if all the antennas are damaged, the base station cannot work normally, and at this time, the base station reports to the background to alarm, and the base station needs to stop working, and can continue working after maintenance personnel perform maintenance or replacement processing. The reduced rank processing scheme of the embodiment is also possible to encounter in practical application, and provides a better guarantee for the reliability of a large-scale antenna system.

By the method and the device, the antenna failure occurs in practical outfield commercial use, and the normal service and basic functions of the base station can be ensured in a non-beam forming scene; in a beamforming scene, the function of beamforming of the base station cannot be affected by channel damage, and the space division performance of the base station can be ensured. The method is of great importance for MassiveMIMO of a large-scale antenna system, on one hand, the reliability and the robustness of a commercial product are improved, and on the other hand, the operation and maintenance cost of the product is also reduced.

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. Through the above description of the embodiments, those skilled in the art will clearly understand that the method of the above embodiments can be implemented by software plus a necessary general hardware platform, and certainly can also be implemented by hardware, but in many cases, the former is a better implementation manner. Based on such understanding, the technical solutions of the embodiments of the present invention may be substantially or partially embodied in the form of a software product, where the computer software product is stored in a storage medium (e.g., a read-only Memory/Random-Access Memory (ROM), a magnetic disk, an optical disk), and includes several instructions for enabling a terminal device (e.g., a mobile phone, a computer, a server, or a network device) to execute the methods according to the embodiments of the present invention.

The above description is only a preferred embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications of equivalent structures and equivalent processes, which are made by using the contents of the present specification and the accompanying drawings, or directly or indirectly applied to other related technical fields, are included in the scope of the present invention.

Claims

1. A channel rank reduction method of a large-scale antenna system comprises the following steps:

performing channel rank reduction processing according to the judgment result of whether the channel has faults;

wherein, the channel rank reduction processing is carried out according to the judgment result of whether the channel has faults, and the method comprises the following steps:

2. The method of claim 1, wherein:

3. The method of claim 2, wherein:

4. The method of claim 3, wherein:

5. The method of claim 4, wherein:

6. The method of claim 1, wherein:

and performing channel rank reduction according to the judgment result of whether the channel has faults, and further comprising:

and if the reference channel has faults and the alternative reference channel has no faults, taking the alternative reference channel without faults as a new reference channel and not performing rank reduction processing on the reference channel.

7. The method of claim 1, wherein:

the channel rank reduction processing is performed according to the judgment result of whether the channel has the fault, and the method further comprises the following steps:

8. The method of claim 1, wherein:

for each common channel with a fault:

9. The method of claim 7 or 8, wherein:

10. The method of any of claims 1-8, wherein:

11. A channel rank reduction method of a large-scale antenna system comprises the following steps:

if the reference channel in at least one direction of the uplink direction and the downlink direction has faults and all the alternative reference channels in the direction have faults, reducing the rank of the reference channel, wherein the reducing the rank of the reference channel comprises the following steps: and closing the uplink channel and/or the downlink channel with faults in the reference channel, and closing the beam forming function of the large-scale antenna system.

12. The method of claim 11, wherein:

and if the reference channel in at least one direction has faults and the alternative reference channels in each direction with the faults of the reference channel have no faults, taking the alternative reference channel without the faults in each direction as a new reference channel in the direction without reducing the rank of the reference channel.

13. A channel rank reduction apparatus of a massive antenna system, comprising:

the rank reduction processing module is used for carrying out channel rank reduction processing according to the judgment result of whether the channel has faults;

14. The apparatus of claim 13, wherein:

15. The apparatus of claim 14, wherein:

16. The apparatus of claim 15, wherein:

17. The apparatus of claim 16, wherein:

18. The apparatus of claim 13, wherein:

the said processing module of rank reduction carries on the rank reduction of the channel according to the judged result whether the said channel has faults, also include:

19. The apparatus of claim 13, wherein:

the said processing module of rank reduction carries on the rank reduction of the channel according to the judged result whether the said channel has faults, also include: and for each common channel with the fault, closing the uplink channel and the downlink channel of the common channel.

20. The apparatus of claim 13, wherein:

the said processing module of rank reduction carries on the rank reduction of the channel according to the judged result whether the said channel has faults, also include: for each common channel with a fault: when the common channel is used for the beamforming service, closing an uplink channel and a downlink channel of the common channel; and when the common channel is not used for the beamforming service, if the uplink channel of the common channel fails, closing the uplink channel, and if the downlink channel of the common channel fails, closing the downlink channel of the common channel.

21. The apparatus of claim 19 or 20, wherein:

22. The apparatus of any of claims 13-20, wherein:

the rank reduction processing module performs channel rank reduction processing according to the judgment result of whether the channel has faults, and the processing method comprises the following steps: firstly, judging whether the number is greater than or equal to a corresponding number threshold; if yes, the beam forming function of the large-scale antenna system is closed, and the uplink channel and the downlink channel with faults are closed; if not, respectively performing rank reduction processing on the reference channel and the common channel.

23. A channel rank reduction apparatus of a massive antenna system, comprising:

the channel rank reduction processing module performs channel rank reduction processing according to the judgment result of whether the channel has faults, and the channel rank reduction processing method comprises the following steps:

24. The apparatus of claim 23, wherein: