201101709 六、發明說明： 【發明所屬之技術領域】 [0001]本發明涉及無線通訊領域，尤其涉及—種多載波干擾消 除電路及使用其的訊號收發系統。 【先前技射ί】 剛在無線收«統巾，當訊號發送電馳由軌通道傳送 訊號至訊號接收電路時，訊號接收電路必須知道訊號的 起始與結束，才能正確解調訊號。但是通訊通道產生的 延遲效應，以及訊號發送電路與訊號接收電路的振盪器 頻率不匹配，都會產生多載波頻率偏移的現象，這將加 大訊號解調的難度，進而造成通訊系統的錯誤率大增。 其中尤以頻率偏移所造成的多載波間干擾對通訊系統效 能影響最為嚴重。 闺目刚’隨著多媒體日益發展，錢網路需要傳輸的訊號 已經不再是單純的語音或文字，而更多的是具聲光效果 的圖文資訊，例如行動電話的語音影像傳輸，無線區域 網（Wireless Local Area Network，WLAN)的高速 資料傳輸等服務專案，這都必須依靠高速傳輸速率才可 以達成。因此，作為無線高速傳輸的主流技術正交頻分 複用（Orthogonal Frequency Division Multiplexing ’ 0FDM) 技術扮演的角 色愈趨 重要， 而克服 OFDM系統收發端之間的頻率偏移所造成的多載波間干擾 效應更是需要一個快速且精確的多載波頻率估測裝置來 改善系統效能。然而，實際情況下，此類多載波頻率估 測裝置接收到的多載波訊號往往會受到其他系統的強訊 098121975 表單編號A0101 第4頁/共24頁 0982037355-0 201101709 [0004] [0005] Ο [0006]BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the field of wireless communications, and more particularly to a multi-carrier interference cancellation circuit and a signal transmission and reception system using the same. [Previous technology] When the signal is sent to the signal receiving circuit, the signal receiving circuit must know the start and end of the signal to correctly demodulate the signal. However, the delay effect generated by the communication channel and the mismatch between the signal transmission circuit and the oscillator frequency of the signal receiving circuit may cause multi-carrier frequency offset, which will increase the difficulty of signal demodulation and cause the error rate of the communication system. Great increase. Among them, the multi-carrier interference caused by the frequency offset has the most serious impact on the performance of the communication system. With the development of multimedia, the signal that the money network needs to transmit is no longer a simple voice or text, but more of a graphic information with sound and light effects, such as voice image transmission of mobile phones, wireless. Service projects such as high-speed data transmission of the Wireless Local Area Network (WLAN) must be achieved by relying on high-speed transmission rates. Therefore, as the mainstream technology of wireless high-speed transmission, the role of Orthogonal Frequency Division Multiplexing (OFDM) technology becomes more and more important, and overcomes the inter-carrier interference caused by the frequency offset between the transceiver terminals of the OFDM system. The effect is a need for a fast and accurate multi-carrier frequency estimation device to improve system performance. However, in actual situations, the multi-carrier signals received by such multi-carrier frequency estimation devices are often subject to strong signals from other systems. 098121975 Form No. A0101 Page 4 of 24 Page 0982037355-0 201101709 [0004] [0005] [0006]
GG
[0007] 098121975 號干擾，若不先行消除該干擾訊號，就會導致後續多載 波頻率估測的精確度受到影響，使得OFDM系統效能得不 到應有的提升。 【發明内容】 有鑒於此，需提供一種多載波干擾消除電路，能消除多 載波訊號中的干擾訊號，以利於進行多載波頻率偏移估 測。 此外，還需提供一種訊號收發系統，能消除多載波訊號 中的干擾訊號，以利於進行多載波頻率偏移估測。 本發明一實施方式所提供的多載波干擾消除電路，用於 消除多載波訊號中的干擾訊號，其中多載波訊號包括第 一訓練序列。多載波干擾消除電路包括訓練序列產生電 路、第一乘法器、第二乘法器、移相電路、缓衝器及加 法電路。訓練序列產生電路用於產生第二訓練序列，第 二訓練序列與第一訓練序列正交。第一乘法器用於將多 載波訊號附上第二訓練序列，以得到新多載波訊號。第 二乘法器用於將第一乘法器輸出的新多載波訊號附上第 二訓練序列，以得到干擾訊號。移相電路用於轉換第二 乘法器輸出的干擾訊號的相位，以獲得干擾訊號的相反 數。緩衝器用於緩存多載波訊號。加法電路用於將緩衝 器所緩存的多載波訊號附上干擾訊號的相反數，以消除 干擾訊號。 本發明一實施方式所提供的訊號收發系統，包括訊號發 送電路、多載波干擾消除電路、頻率偏移估測電路及訊 號接收電路。訊號發送電路用於將多載波訊號附上第一 表單編號A0101 第5頁/共24頁 0982037355-0 201101709 訓練序列再送出。多载波干擾消除電路用於經由通訊通 道從訊號發送電路接收附上第一訓練序列的多载波气號 ，並消除其他系統對多載波訊號的干擾訊號。頻率偏移 估測電路用於估測已消除干擾訊號的多載波訊號的頻率 偏移。訊號接收電路用於接收頻率偏移估測電路所輸出 的多載波訊號。其中，多載波干擾消除電路包括訓練序 列產生電路、第一乘法器、第二乘法器、移相電路、緩 衝器及加法電路。訓練序列產生電路用於產生第二訓練 序列’第二訓練序列與第一訓練序列正交。第一乘法器 用於將多載波訊號附上第二訓練序列，以得到新多载波 λ號。第一乘法器用於將第一乘法器輸出的新多載波訊 號附上第二訓練序列，以得到干擾訊號。移相電路用於 轉換第一乘法器輸出的干擾訊號的相位，以獲得干擾訊 號的相反數。緩衝器用於緩存多載波訊號。加法電路用 於將緩衝器所緩存的多載波訊號附上干擾訊號的相反數 ’以消除干擾訊號。 [〇〇〇8]藉由以下對具體實施方式詳細的描述並結合附圖，將可 輕易的瞭解上述内容及此項發明之技術效果。 【實施方式】 [〇〇〇9]請參閱圖1，所示為本發明訊號收發系統10_實施方式的 模組圖。 [〇〇1〇]訊號收發系統10包括訊號發送電路12、通訊通道13、多 載波干擾消除電路14、頻率偏移估測電路16及訊號接收 電路18。在本實施方式中，訊號發送電路12將多載波訊 號 098121975 表單編號Α0101 第6頁/共24頁 0982037355-0 201101709 s(n) 經由通訊通道13發送給訊號接收電路18，此時，多載波 訊號 經過通訊通道13已成為多載波訊號 r(w) Ο 。在本實施方式中，多載波訊號為正交頻分複用（Orthogonal Frequency Division Multiplexing， OFDM)訊號，通訊通道13為加性白高斯雜訊（Additive White Gaussion Noise，AWGN)通道。 [0011] 在本實施方式中，訊號發送電路12與訊號接收電路18的 多載波訊號 ❹[0007] Interference No. 098121975, if the interference signal is not eliminated first, the accuracy of the subsequent multi-carrier frequency estimation will be affected, and the performance of the OFDM system will not be improved as expected. SUMMARY OF THE INVENTION In view of the above, it is desirable to provide a multi-carrier interference cancellation circuit that can eliminate interference signals in a multi-carrier signal to facilitate multi-carrier frequency offset estimation. In addition, a signal transceiving system is needed to eliminate interfering signals in multi-carrier signals for multi-carrier frequency offset estimation. A multi-carrier interference cancellation circuit according to an embodiment of the present invention is configured to eliminate interference signals in a multi-carrier signal, wherein the multi-carrier signal includes a first training sequence. The multicarrier interference cancellation circuit includes a training sequence generating circuit, a first multiplier, a second multiplier, a phase shifting circuit, a buffer, and an adding circuit. The training sequence generation circuit is operative to generate a second training sequence that is orthogonal to the first training sequence. The first multiplier is configured to attach the multi-carrier signal to the second training sequence to obtain a new multi-carrier signal. The second multiplier is configured to attach the second multi-carrier signal output by the first multiplier to the second training sequence to obtain an interference signal. The phase shifting circuit is used to convert the phase of the interference signal output by the second multiplier to obtain the opposite of the interference signal. The buffer is used to buffer the multi-carrier signal. The adding circuit is used to add the opposite of the interference signal to the multi-carrier signal buffered by the buffer to eliminate the interference signal. A signal transceiving system according to an embodiment of the present invention includes a signal transmitting circuit, a multi-carrier interference canceling circuit, a frequency offset estimating circuit, and a signal receiving circuit. The signal transmitting circuit is used to attach the multi-carrier signal to the first form number A0101. Page 5 of 24 0982037355-0 201101709 The training sequence is sent again. The multi-carrier interference cancellation circuit is configured to receive the multi-carrier air number with the first training sequence from the signal transmitting circuit via the communication channel, and eliminate the interference signal of the other system to the multi-carrier signal. The frequency offset estimation circuit is used to estimate the frequency offset of the multi-carrier signal from which the interference signal has been cancelled. The signal receiving circuit is configured to receive the multi-carrier signal output by the frequency offset estimation circuit. The multi-carrier interference cancellation circuit includes a training sequence generating circuit, a first multiplier, a second multiplier, a phase shifting circuit, a buffer, and an adding circuit. Training sequence generation circuitry is operative to generate a second training sequence. The second training sequence is orthogonal to the first training sequence. The first multiplier is used to attach the multi-carrier signal to the second training sequence to obtain a new multi-carrier λ number. The first multiplier is configured to attach the new multi-carrier signal output by the first multiplier to the second training sequence to obtain an interference signal. The phase shifting circuit is configured to convert the phase of the interference signal output by the first multiplier to obtain the opposite of the interference signal. The buffer is used to buffer the multi-carrier signal. The summing circuit is operative to append the multi-carrier signal buffered by the buffer to the opposite of the interfering signal to eliminate the interfering signal. The above and the technical effects of the invention will be readily understood by the following detailed description of the embodiments and the accompanying drawings. [Embodiment] [〇〇〇9] Please refer to Fig. 1, which is a block diagram of an embodiment of a signal transmitting and receiving system 10_ of the present invention. The signal transmitting and receiving system 10 includes a signal transmitting circuit 12, a communication channel 13, a multi-carrier interference canceling circuit 14, a frequency offset estimating circuit 16, and a signal receiving circuit 18. In the present embodiment, the signal transmitting circuit 12 transmits the multi-carrier signal 098121975 form number Α0101 page 6/24 pages 0982037355-0 201101709 s(n) to the signal receiving circuit 18 via the communication channel 13, at this time, the multi-carrier signal After the communication channel 13 has become a multi-carrier signal r (w) Ο. In this embodiment, the multi-carrier signal is an Orthogonal Frequency Division Multiplexing (OFDM) signal, and the communication channel 13 is an Additive White Gaussian Noise (AWGN) channel. [0011] In the present embodiment, the multi-carrier signal of the signal transmitting circuit 12 and the signal receiving circuit 18
與 r(n) 之間存在本地振盪器不匹配而造成的頻率偏移 ε ，並且受到其他系統的干擾訊號，訊號接收電路18所接 收的多載波訊號 098121975 表單編號Α0101 第7頁/共24頁 0982037355-0 201101709 r(n) 等於訊號發送電路12所發射的訊號 乘上頻率偏移所造成的相位旋轉及加上雜訊 η(ή) 、其他系統的干擾訊號 /(Μ) ，具體如（1)式 [0012] .·ε·η s(ri)eJ N +/?(«) + /(/?) (1) [0013] 其中j表示虛數，N為多載波訊號的多載波個數， η(ή) 為複數白色高斯雜訊，其期望值（mean)為0，變異數 (variance)為 ，且實部與虛部互為獨立。 [0014] 訊號發送電路12用於將多載波訊號 098121975 表單編號Α0101 第8頁/共24頁 0982037355-0 201101709 J(W) 附上第一訓練序列 Φ) 並經由通訊通道13送出。在本實施方式中，訊號發送電 路12藉由乘法器將多載波訊號 〇 與第一訓練序列 C⑻ 相乘，以將多載波訊號 J<M) 附上一串第一訓練序列 〇 c(n) ，即訊號發送電路12所傳送出去的多載波訊號為 Φ) 〇 [0015] 多載波干擾消除電路14用於經由通訊通道13從訊號發送 098121975 表單編號 A0101 第 9 頁/共 24 頁 0982037355-0 201101709 電路12接收附上一串第一訓練序列 Φ) 的多載波訊號 r(n) ，並消除其他系統對多載波訊號 r(n) 的干擾訊號 J⑻ 。在本實施方式中，多載波干擾消除電路1 4經由通訊通 道13從訊號發送電路12接收附上第一訓練序列後的多載 波訊號。訊號發送電路12附上第一訓練序列 Φ) 後所傳送的多載波訊號 Φ) 經過AWGN通道後可表示成： [0016] r(n)- c(n)ej('2n'^'n+eQ^ + n{n) +1(η) 098121975 表單編號A0101 第10頁/共24頁 0982037355-0 (2)201101709 [0017] 其中， c(«) 為統計獨立的M-ary相移鍵控（Phase Shift Keying， PSK)訊號，且 Ο 〇 [0018] [0019] 098121975There is a frequency offset ε caused by the local oscillator mismatch with r(n), and is interfered by other systems. The multi-carrier signal received by the signal receiving circuit 18 is 098121975 Form No. 1010101 Page 7 of 24 0982037355-0 201101709 r(n) is equal to the phase rotation caused by the signal transmitted by the signal transmitting circuit 12 multiplied by the frequency offset and the noise η(ή), the interference signal of other systems/(Μ), such as ( 1) Formula [0012] .·ε·η s(ri)eJ N +/?(«) + /(/?) (1) [0013] where j represents an imaginary number and N is the number of multicarriers of the multicarrier signal , η(ή) is a complex white Gaussian noise, the expected value (mean) is 0, the variance is (variance), and the real part and the imaginary part are independent of each other. [0014] The signal transmitting circuit 12 is configured to send the multi-carrier signal 098121975 form number Α0101 page 8/24 pages 0982037355-0 201101709 J(W) with the first training sequence Φ) and send it via the communication channel 13. In this embodiment, the signal transmitting circuit 12 multiplies the multi-carrier signal 〇 by the first training sequence C(8) by the multiplier to attach the multi-carrier signal J<M) to the first training sequence 〇c(n) That is, the multi-carrier signal transmitted by the signal transmitting circuit 12 is Φ) 〇 [0015] The multi-carrier interference canceling circuit 14 is used to transmit from the signal via the communication channel 13 098121975 Form No. A0101 Page 9 of 24 0982037355-0 201101709 The circuit 12 receives the multi-carrier signal r(n) with a series of first training sequences Φ) and eliminates the interference signal J(8) of the other system to the multi-carrier signal r(n). In the present embodiment, the multi-carrier interference canceling circuit 14 receives the multi-carrier signal after the first training sequence is attached from the signal transmitting circuit 12 via the communication channel 13. The multi-carrier signal Φ transmitted after the signal transmission circuit 12 is attached with the first training sequence Φ) can be expressed after the AWGN channel: [0016] r(n)-c(n)ej('2n'^'n+ eQ^ + n{n) +1(η) 098121975 Form No. A0101 Page 10 of 24 0982037355-0 (2) 201101709 [0017] where c(«) is a statistically independent M-ary phase shift keying (Phase Shift Keying, PSK) signal, and Ο 〇 [0018] [0019] 098121975
A 為未知的初始相位， Δ/ = ε Ν 為正規化頻率偏移。此時，根據teeter，s雜訊近似理 論，可將（2)式改寫成： (3) 令.n(n) = v(n)~ q(n)+ ju(n) ，其中 表單編號A0101 第11頁/共24頁 0982037355-0 2 201101709 V(M) 也是複數白色高斯雜訊，變異數為A is the unknown initial phase, and Δ/ = ε Ν is the normalized frequency offset. At this time, according to the teeter, s noise approximation theory, the equation (2) can be rewritten as: (3) Let .n(n) = v(n)~ q(n)+ ju(n) , where the form number A0101 Page 11 of 24 0982037355-0 2 201101709 V(M) is also a complex white Gaussian noise with a variance of
。將 v(«) 代入（3 )，可得到 [0020] [0021] [1+ν(η)]ο(η)βΛ2πΑ/·η+^ +1 (η) =[(1+^(^) + j ·Μ(η)]α(η)ΘΚ2π Α/ κ+θΰ) + I(η) = ο(η)βΛ2π Α^+θΌ) + 1{η) (4) 其中， R = ^[〇· + ^(^))2 + u(n)2 ㈣紐-1!；」⑷] 1 + q(n) 此％，因多载波干擾消除電路丨4所接收的多載波訊號 098121975 表單蝙號A0101 第12頁/共24頁 0982037355-0 201101709 γ(«) 處於高訊雜比的條件下，雜訊功率很小，所以（4)式可近 似成 [0022] Ο [(1 + q(n) + j u{n)\:{n)eJ('2n^f n+8ii) +1(η) ,-/tan-1[々⑷] = ^(1+ q(n)f + u(nf e 1+咖+/(/z) e c⑻Δ/ MV.tan_1[wW] + /⑻ « c(n)eJi2ft A/n+e〇)eJ u(f,) + I(n) e ♦)严△，吟"⑽+ /⑻ (5) [0023] 其中， var(M ⑻）= —var(v⑻）= 2 σ 2 η 2 Ο [0024] 由（5 )式可知，當複數白色高斯雜訊近似成相位雜訊時， 多載波干擾消除電路14所接收的多載波訊號 r(n) 可表示成第一訓練序列 c⑻ 旋轉相位加上干擾訊號 098121975 表單編號A0101 第13頁/共24頁 0982037355-0 201101709 J(«) [0025] ，即： (6) π'^ίη+ ^ + + /(κ) [0026] 閱圖2，為圖i所示的多載波干擾消除電路i4的具體 電路圖在本貝施方式中，多載波干擾消除電路η包括 訓練序列產生電路14〇、第一乘法器⑷、第二乘法器 142移相電路143、緩衝器144及加法電路145。 [0027] 訓練序列產生電路140用於產生帛二訓練序列 办⑻ ’其中第二訓練序列 Κη) 與第一訓練序列 Φ) 呈現正交關係，且 [0028] 098121975 第一乘法器 表單編號ΑΟ】〇】. Substituting v(«) into (3) gives [0020] [1+ν(η)] ο(η)βΛ2πΑ/·η+^ +1 (η) =[(1+^(^) + j ·Μ(η)]α(η)ΘΚ2π Α/ κ+θΰ) + I(η) = ο(η)βΛ2π Α^+θΌ) + 1{η) (4) where R = ^[〇 · + ^(^))2 + u(n)2 (4) New-1!;"(4)] 1 + q(n) This %, multi-carrier signal received by multi-carrier interference cancellation circuit 丨4 098121975 Form bat number A0101 Page 12 of 24 0982037355-0 201101709 γ(«) Under the condition of high signal-to-noise ratio, the noise power is very small, so (4) can be approximated as [0022] Ο [(1 + q(n ) + ju{n)\:{n)eJ('2n^f n+8ii) +1(η) , -/tan-1[々(4)] = ^(1+ q(n)f + u(nf e 1+咖+/(/z) e c(8)Δ/ MV.tan_1[wW] + /(8) « c(n)eJi2ft A/n+e〇)eJ u(f,) + I(n) e ♦) △,吟"(10)+ /(8) (5) where var(M (8))= —var(v(8))= 2 σ 2 η 2 Ο [0024] From (5), when the complex white Gaussian When the signal is approximated to phase noise, the multi-carrier signal r(n) received by the multi-carrier interference cancellation circuit 14 can be expressed as the first training sequence c(8), the rotation phase plus the interference signal 098121975, the form number A0101 Page 13 of 24 page 0982037355-0 201101709 J(«) [0025] , ie: (6) π'^ίη+ ^ + + /(κ) [0026] Read Figure 2, which is shown in Figure i Specific circuit diagram of carrier interference cancellation circuit i4 In the present embodiment, the multi-carrier interference cancellation circuit η includes a training sequence generation circuit 14A, a first multiplier (4), a second multiplier 142 phase shift circuit 143, a buffer 144, and addition. Circuit 145. [0027] The training sequence generating circuit 140 is configured to generate a second training sequence (8) 'where the second training sequence Κn) and the first training sequence Φ) exhibit an orthogonal relationship, and [0028] 098121975 first multiplier form number ΑΟ] 〇】
ία用於將多载波干擾消除 苐Μ頁/共24頁 電路14所接收的多 0982037355-0 201101709 載波訊號 r(«) 附上第二訓練序列 b(n) ，以得到新多載波訊號 y{n) 〇 。在本實施方式中，第一乘法器141將第二訓練序列Ία is used to add the multi-carrier interference cancellation page/total 24 page circuit 14 to receive the multi-0982037355-0 201101709 carrier signal r(«) with the second training sequence b(n) to obtain the new multi-carrier signal y{ n) 〇. In the present embodiment, the first multiplier 141 will be the second training sequence.
Kn) 與多載波訊號 r(M) 相乘，可得 〇 [〇〇29] y(n) = b(n)· + b^n). /(w) (7) [0030] 因第二訓練序列Kn) Multiply the multi-carrier signal r(M) to obtain 〇[〇〇29] y(n) = b(n)· + b^n). /(w) (7) [0030] Training sequence
Kn) 與第一訓練序列 Φ) 098121975 表單編號 Α0101 第 15 頁/共 24 頁 0982037355-0 201101709 呈現正交關係，所以（7)式可轉換為 y(n) = b(n)-I(n) [0031] 第二乘法器142用於將第一乘法器141輸出的新多載波訊 號 y{n) 附上第二訓練序列 办(《) 。在本實施方式中，第二乘法器142將第二訓練序列Kn) and the first training sequence Φ) 098121975 Form number Α0101 page 15 / 24 page 0982037355-0 201101709 presents an orthogonal relationship, so (7) can be converted to y(n) = b(n)-I(n [0031] The second multiplier 142 is configured to attach the new multi-carrier signal y{n) output by the first multiplier 141 to the second training sequence ("). In this embodiment, the second multiplier 142 will be the second training sequence.
Kn) 與新多載波訊號 y⑻ 相乘，由於 b(n)2 =1 ，可得 [0032] ? y{n)-b{n) - \b(n) Ί(η) = I(η) (8) 098121975 表單編號A0101 第16頁/共24頁 0982037355-0 201101709 [0033] 此時，可知第二乘法器142輸出的即為其他系統對 r(n) 的干擾訊號 /(M) 〇 [0034] Ο 移相電路143用於轉換第二乘法器輸出的干擾訊號 /(M) 的相位，以獲得干擾訊號的相反數 -/(M) 〇 [0035] ❹ 緩衝器144用於緩存多載波干擾消除電路14所接收的多載 波訊號 r(n) [0036] 加法電路14 5用於將移相電路14 3所輸出的 —/⑻ 附加到緩衝器144所輸出的 r⑻ 098121975 表單編號A0101 第17頁/共24頁 0982037355-0 201101709 ，以消除干擾訊號 /(M) 。在本實施方式中，加法電路145藉由加法器將（6)式與 移相電路143所輸出的 -/⑻ 相加，可得 [0037] [0038] z{n) = +1 (η)-I (η) (9) 此時，由（9)式可知，已將多載波干擾消除電路14所接收 的多載波訊號 r(n) 中的干擾訊號 /⑻ 消除，多載波干擾消除電路14所輸出的多載波訊號 Z⑻ 已經不包括干擾訊號 /⑻ 098121975 表單編號A0101 第18頁/共24頁 0982037355-0 201101709 [0039] [0040] 〇 [0041] [0042] Ο [0043] [0044] [0045] 頻率偏移估測電路1 6用於估測經多載波干擾消除電路14 消除干擾訊號的多載波訊號 的頻率偏移。 訊號接收電路18用於接收頻率偏移估測電路1 6所輸出的 多載波訊號。 本發明實施方式所提供的多載波干擾消除電路14及使用 其的訊號收發系統10採用簡單的乘法、移相以及加法等 電路’成功地消除了多載波訊號中的干擾訊號，從而大 大提升後續多載波頻率估測的精確度，有效提升OFDM技 術的傳輸效率。 綜上所述，本發明符合發明專利要件，爰依法提出專利 申請。惟’以上所述者僅為本發明之較佳實施例，舉凡 熟悉本案技藝之人士，在爰依本案發明精神所作之等效 修飾或變化，皆應包含於以下之申請專利範圍内。 【圖式簡單說明】 圖1為本發明訊號收發系統一實施方式的模組圖。 圖2為圖1所示的多載波干擾消除電路一實施方式的具體 電路圖。 【主要元件符號說明】 訊號收發系統 098121975 表單編號A0101 第19頁/共24頁 0982037355-0 201101709 [0046] 訊號發送電路12 [0047] 多載波干擾消除電路14 [0048] 頻率偏移估測電路1 6 [0049] 訊號接收電路18 [0050] 訓練序列產生電路140 [0051] 第一乘法器141 [0052] 第二乘法器142 [0053] 移相電路14 3 [0054] 缓衝器144 [0055] 加法電路145 098121975 表單編號A0101 第20頁/共24頁 0982037355-0Kn) multiplied by the new multi-carrier signal y(8). Since b(n)2 =1, we can get [0032] y{n)-b{n) - \b(n) Ί(η) = I(η) (8) 098121975 Form No. A0101 Page 16 of 24 0982037355-0 201101709 [0033] At this time, it can be seen that the second multiplier 142 outputs the interference signal /(M) of other systems to r(n). 0034] 移 Phase shift circuit 143 is used to convert the phase of the interference signal /(M) output by the second multiplier to obtain the opposite of the interference signal -/(M) 〇[0035] 缓冲器 Buffer 144 is used to buffer the multi-carrier The multi-carrier signal r(n) received by the interference cancellation circuit 14 [0036] The addition circuit 14 5 is for appending the -/(8) output from the phase shifting circuit 14 3 to the r(8) output from the buffer 144. 098121975 Form No. A0101 No. 17 Page / Total 24 pages 0982037355-0 201101709 to eliminate interference signals / (M). In the present embodiment, the adding circuit 145 adds the equation (6) to -/(8) output from the phase shifting circuit 143 by the adder, and obtains [0037] [0038] z{n) = +1 (η) -I (η) (9) At this time, it is known from equation (9) that the interference signal /(8) in the multicarrier signal r(n) received by the multicarrier interference canceling circuit 14 has been cancelled, and the multicarrier interference canceling circuit 14 The output multi-carrier signal Z(8) does not include the interference signal/(8) 098121975 Form No. A0101 Page 18/24 pages 0982037355-0 201101709 [0040] [0040] [0041] [0042] Ο [0043] [0044] The frequency offset estimation circuit 16 is configured to estimate the frequency offset of the multi-carrier signal by which the multi-carrier interference cancellation circuit 14 cancels the interference signal. The signal receiving circuit 18 is configured to receive the multi-carrier signal output by the frequency offset estimating circuit 16. The multi-carrier interference cancellation circuit 14 and the signal transceiving system 10 using the same according to the embodiments of the present invention successfully eliminate the interference signals in the multi-carrier signal by using simple multiplication, phase shifting and addition circuits, thereby greatly improving the subsequent multi-carrier signals. The accuracy of carrier frequency estimation effectively improves the transmission efficiency of OFDM technology. In summary, the present invention complies with the requirements of the invention patent and submits a patent application according to law. However, the above description is only the preferred embodiment of the present invention, and equivalent modifications or variations made by those skilled in the art will be included in the following claims. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of an embodiment of a signal transceiving system according to the present invention. Fig. 2 is a detailed circuit diagram of an embodiment of the multicarrier interference canceling circuit shown in Fig. 1. [Description of Main Components] Signal Transceiver System 099121975 Form No. A0101 Page 19/24 pages 0982037355-0 201101709 [0046] Signal Transmitting Circuit 12 [0047] Multi-Carrier Interference Cancellation Circuit 14 [0048] Frequency Offset Estimation Circuit 1 [0049] Signal receiving circuit 18 [0050] Training sequence generating circuit 140 [0051] First multiplier 141 [0052] Second multiplier 142 [0053] Phase shifting circuit 14 3 [0054] Buffer 144 [0055] Addition circuit 145 098121975 Form number A0101 Page 20 / Total 24 page 0982037355-0
| Application Number | Priority Date | Filing Date | Title |
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| TW98121975ATWI474628B (en) | 2009-06-30 | 2009-06-30 | Multi-carrier interference eliminating circuit and signal transceiving system employing the same |
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| TW98121975ATWI474628B (en) | 2009-06-30 | 2009-06-30 | Multi-carrier interference eliminating circuit and signal transceiving system employing the same |
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| TW201101709Atrue TW201101709A (en) | 2011-01-01 |
| TWI474628B TWI474628B (en) | 2015-02-21 |
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| TW98121975ATWI474628B (en) | 2009-06-30 | 2009-06-30 | Multi-carrier interference eliminating circuit and signal transceiving system employing the same |
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