TWI794001B - Radio frequency self-interference elimination method for full-duplex wireless receiver - Google Patents
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Abstract
本發明為一種全雙工無線接收機之射頻消除自我干擾方法,包括建立一射頻不完美聯合訊號模型。輸入主路訊號與輔路訊號至射頻不完美聯合訊號模型中,以合成產生不完美輸出訊號。根據射頻不完美聯合訊號模型及不完美輸出訊號,對主路訊號與該輔路訊號之通道濾波響應進行估測,以取得主路訊號及輔路訊號之通道濾波響應參數。根據主路訊號及輔路訊號之通道濾波響應參數,補償射頻不完美聯合訊號模型之通道濾波響應,並估算測出預補償參數,以補償不完美輸出訊號。本發明能估測出訊號中的預補償參數,以解決收發機訊號洩漏的問題,提升訊號傳遞效益。The invention is a radio frequency self-interference elimination method of a full-duplex wireless receiver, which includes establishing a radio frequency imperfect combined signal model. Input the main channel signal and the auxiliary channel signal to the RF imperfect joint signal model to synthesize an imperfect output signal. According to the RF imperfect joint signal model and the imperfect output signal, estimate the channel filter response of the main channel signal and the auxiliary channel signal, so as to obtain the channel filter response parameters of the main channel signal and the auxiliary channel signal. According to the channel filter response parameters of the main channel signal and the auxiliary channel signal, the channel filter response of the RF imperfect joint signal model is compensated, and the pre-compensation parameters are estimated to compensate for the imperfect output signal. The invention can estimate the pre-compensation parameters in the signal, so as to solve the problem of signal leakage of the transceiver and improve the efficiency of signal transmission.
Description
本發明係有關一種訊號傳輸技術,特別是指一種全雙工無線接收機之射頻消除自我干擾方法。 The invention relates to a signal transmission technology, in particular to a radio frequency self-interference elimination method of a full-duplex wireless receiver.
訊號傳輸時,相同的頻帶上若同時進行發送和接收,會導致嚴重的自我干擾,因此為解決上述問題,現今的無線通訊都是以半雙工的形式傳送。但無線全雙工傳送可提升更高的頻譜使用效率,因此如何消除全雙工無線接收機的自我干擾,對於全雙工無線接收機來說是至關重要的問題。 During signal transmission, if simultaneous transmission and reception are performed on the same frequency band, it will cause serious self-interference. Therefore, in order to solve the above problems, today's wireless communications are transmitted in the form of half-duplex. However, wireless full-duplex transmission can improve higher spectrum utilization efficiency, so how to eliminate the self-interference of the full-duplex wireless receiver is a crucial issue for the full-duplex wireless receiver.
無線傳收機在同時發射與接收訊號時,自身發射訊號環回進入接收端,其中微波發射和反射是自我干擾引發的原因之一。近年來為了克服此問題,提出方法有天線分離、天線消除、類比消除和數位消除等方法。但上述這些方法,礙於天線分離與天線消除,易受到天線與天線間隔的距離,及可用物理設備的空間限制。 When the wireless transceiver transmits and receives signals at the same time, the self-transmitting signal loops back into the receiving end, and microwave transmission and reflection are one of the reasons for self-interference. In order to overcome this problem in recent years, methods such as antenna separation, antenna cancellation, analog cancellation and digital cancellation have been proposed. However, these methods mentioned above are easily limited by the distance between antennas and the space of available physical devices due to antenna separation and antenna elimination.
有鑑於此,本發明遂針對上述習知技術之缺失,提出一種全雙工無線接收機之射頻消除自我干擾方法,以有效克服上述之該等問題。 In view of this, the present invention proposes a radio frequency self-interference elimination method for a full-duplex wireless receiver to effectively overcome the above-mentioned problems.
本發明之主要目的在提供一種全雙工無線接收機之射頻消除自我干擾方法,其能估測出訊號中的通道濾波響應以及預補償參數,以解決收發機訊號洩漏的問題,提升收發機間的隔離度性能,提升訊號傳遞效益。 The main purpose of the present invention is to provide a radio frequency self-interference elimination method for a full-duplex wireless receiver, which can estimate the channel filter response and pre-compensation parameters in the signal, so as to solve the problem of transceiver signal leakage and improve the communication between transceivers. Excellent isolation performance to improve signal transmission efficiency.
本發明之另一目的在提供一種全雙工無線接收機之射頻消除自我干擾方法,其能估測出訊號中的振幅(In-phase,I)不平衡參數及相位(Quadrature,Q)不平衡參數的問題,以對訊號進行補償,提升訊號傳遞效益。 Another object of the present invention is to provide a radio frequency self-interference elimination method for a full-duplex wireless receiver, which can estimate the amplitude (In-phase, I) imbalance parameter and phase (Quadrature, Q) imbalance in the signal The problem of parameters is used to compensate the signal and improve the efficiency of signal transmission.
為達上述之目的,本發明係提供一種全雙工無線接收機之射頻消除自我干擾方法,包括下列步驟,建立一射頻不完美聯合訊號模型。輸入主路訊號與輔路訊號至射頻不完美聯合訊號模型中,以將主路訊號與輔路訊號合成,產生不完美輸出訊號。根據射頻不完美聯合訊號模型及不完美輸出訊號,利用最小平方法或最小均方法對主路訊號與輔路訊號之通道濾波響應進行估測,以取得主路訊號之通道濾波響應參數及輔路訊號之通道濾波響應參數。根據主路訊號之通道濾波響應參數及輔路訊號之通道濾波響應參數,補償射頻不完美聯合訊號模型之通道濾波響應,以估算測出預補償參數。利用預補償參數補償不完美輸出訊號。 In order to achieve the above purpose, the present invention provides a radio frequency self-interference elimination method for a full-duplex wireless receiver, which includes the following steps to establish a radio frequency imperfect combined signal model. Input the main channel signal and the auxiliary channel signal to the RF imperfect joint signal model to synthesize the main channel signal and the auxiliary channel signal to generate an imperfect output signal. According to the RF imperfect joint signal model and the imperfect output signal, use the least square method or the least average method to estimate the channel filter response of the main channel signal and the auxiliary channel signal, so as to obtain the channel filter response parameters of the main channel signal and the channel filter response parameters of the auxiliary channel signal. Channel filter response parameters. According to the channel filter response parameters of the main channel signal and the channel filter response parameters of the auxiliary channel signal, the channel filter response of the radio frequency imperfect joint signal model is compensated to estimate and measure the pre-compensation parameters. Compensate for imperfect output signals using precompensation parameters.
在本實施例中,射頻不完美聯合訊號模型表示為:
在本實施例中,利用最小平方法或最小均方法對主路訊號與該輔路訊號之通道濾波響應進行估測之步驟中,係使用最小均方法(Least Mean Square,LMS)對主路訊號與輔路訊號之通道濾波響應進行估測,包括下列步驟,首先將不完美輸出訊號帶入最小均方法式,表示為:
J LMS =avg{e[n]e *[n]}
其中
在本實施例中,根據主路訊號之通道濾波響應參數及輔路訊號之通道濾波響應參數,補償射頻不完美聯合訊號模型之通道濾波響應,並估算測出預補償參數之步驟更包括,加入預補償代數至射頻不完美聯合訊號模型,以建立理想射頻聯合訊號模型。帶入主路訊號之通道濾波響應參數及輔路訊號之通道濾波響應參數至理想射頻聯合訊號模型中,以估測出預補償參數。 In this embodiment, according to the channel filter response parameters of the main channel signal and the channel filter response parameters of the auxiliary channel signal, the step of compensating the channel filter response of the radio frequency imperfect joint signal model, and estimating and measuring the precompensation parameters further includes: Compensate algebraically to the RF imperfect joint signal model to create an ideal RF joint signal model. Bring the channel filter response parameters of the main channel signal and the channel filter response parameters of the auxiliary channel signal into the ideal radio frequency joint signal model to estimate the pre-compensation parameters.
在本實施例中,理想射頻聯合訊號模型表示為:
在本實施例中,帶入主路訊號之通道濾波響應參數及輔路訊號之通道濾波響應參數至理想射頻聯合訊號模型中,以估測出預補償參數之步驟更包括:將轉換為矩陣形,表示為:c M =-C A q A q A 為q A (n)的向量表示,C A 為該c A (n)的常對角矩陣(Toeplitz)表示;使用偽逆矩陣(Pseudoinverse)轉換q A ,以估測出預補償參數,偽逆矩陣的q A 表示為:q A =-(C A H C A )-1 C A H c M 。 In this embodiment, the step of bringing the channel filter response parameters of the main channel signal and the channel filter response parameters of the auxiliary channel signal into the ideal radio frequency joint signal model to estimate the precompensation parameters further includes: Converted to a matrix form, expressed as: c M =- C A q A q A is the vector representation of q A ( n ), C A is the constant diagonal matrix (Toeplitz) representation of the c A ( n ); using pseudo-inverse The matrix (Pseudoinverse) transforms q A to estimate the pre-compensation parameters, and the q A of the pseudo-inverse matrix is expressed as: q A =-( C A H C A ) -1 C A H c M .
在本實施例中,在根據射頻不完美聯合訊號模型及不完美輸出訊號,對主路訊號與輔路訊號之通道濾波響應進行估測,以取得主路訊號之通道濾波響應參數及輔路訊號之通道濾波響應參數之步驟中,更包括對主路訊號與輔路訊號的振幅(In-phase,I)不平衡參數及相位(Quadrature,Q)不平衡參數,及主路訊號與該輔路訊號的振幅通道的振幅通道濾波響應參數,以及主路訊號與該輔路訊號的相位通道的相位通道濾波響應參數進行估測。 In this embodiment, according to the RF imperfect joint signal model and the imperfect output signal, the channel filter responses of the main channel signal and the auxiliary channel signal are estimated to obtain the channel filter response parameters of the main channel signal and the channel of the auxiliary channel signal In the step of filtering response parameters, the amplitude (In-phase, I) unbalance parameter and phase (Quadrature, Q) unbalance parameter of the main channel signal and the auxiliary channel signal, and the amplitude channel of the main channel signal and the auxiliary channel signal are also included. The amplitude channel filter response parameters of the main channel signal and the phase channel filter response parameters of the phase channels of the main channel signal and the auxiliary channel signal are estimated.
在本實施例中,射頻不完美聯合訊號模型表示為:
在本實施例中,對主路訊號與輔路訊號的振幅通道的振幅通道濾波響應參數,以及主路訊號與輔路訊號的相位通道的相位通道濾波響應參數進行估測之步驟中,係使用最小均方法(Least Mean Square,LMS)進行估測,包括下列步驟,將不完美輸出訊號帶入最小均方法式,表示為:J LMS =avg{e[n]e *[n]}其中
在本實施例中,根據通道濾波響應參數,補償射頻不完美聯合訊號模型之通道濾波響應,並估算測出預補償參數之步驟更包括對主路訊號與輔路訊號的振幅通道的振幅預補償參數,以及相位通道的相位預補償參數進行估測,其步驟更包括,加入振幅預補償代數及相位預補償代數至射頻不完美聯合訊號模型,以建立理想射頻聯合訊號模型。帶入振幅通道濾波響應參數、相位通道濾波響應參數、振幅不平衡參數及相位不平衡參數至理想射頻聯合訊號模型中,以估測出振幅預補償參數及相位預補償參數。 In this embodiment, according to the channel filter response parameters, the channel filter response of the RF imperfect joint signal model is compensated, and the step of estimating and measuring the pre-compensation parameters further includes the amplitude pre-compensation parameters of the amplitude channels of the main channel signal and the auxiliary channel signal , and the phase precompensation parameters of the phase channel are estimated, and the steps further include adding amplitude precompensation algebra and phase precompensation algebra to the radio frequency imperfect joint signal model to establish an ideal radio frequency joint signal model. Bring the amplitude channel filter response parameters, phase channel filter response parameters, amplitude imbalance parameters and phase imbalance parameters into the ideal radio frequency joint signal model to estimate the amplitude precompensation parameters and phase precompensation parameters.
在本實施例中,理想射頻聯合訊號模型表示為:
在本實施例中,帶入振幅通道濾波響應參數、相位通道濾波響應參數、振幅不平衡參數及相位不平衡參數至理想射頻聯合訊號模型中,以估測出振幅預補償參數及相位預補償參數之步驟更包括,將理想射頻聯合訊號模型轉換為矩陣,其表示為:
底下藉由具體實施例詳加說明,當更容易瞭解本發明之目的、技術內容、特點及其所達成之功效。 In the following detailed description by means of specific embodiments, it will be easier to understand the purpose, technical content, characteristics and effects of the present invention.
1:收發機 1: Transceiver
10:主路訊號發射器 10: Main road signal transmitter
12:輔路訊號發射器 12: Auxiliary road signal transmitter
14:參數估測器 14: Parameter Estimator
16:線性濾波器 16: Linear filter
18:切換器 18:Switcher
20:主路濾波器 20: Main road filter
22:輔路濾波器 22: Auxiliary channel filter
24:訊號接收器 24: Signal receiver
S10~S18:步驟 S10~S18: Steps
第一圖係為本發明方法應用之收發機系統示意圖。 The first figure is a schematic diagram of a transceiver system where the method of the present invention is applied.
第二圖係為本發明之方法流程圖。 The second figure is a flow chart of the method of the present invention.
第三圖係為本發明之訊號預補償前後比較頻譜圖。 The third figure is a comparison spectrum diagram before and after the signal pre-compensation of the present invention.
第四圖係為本發明另一實施例之訊號預補償前後比較頻譜圖。 The fourth figure is a comparison spectrum diagram before and after signal pre-compensation according to another embodiment of the present invention.
本實施例能估測出訊號中的通道濾波響應及預補償參數,以解決收發機訊號洩漏的問題,提升收發機間的隔離度性能,提升訊號傳遞效益。 This embodiment can estimate the channel filter response and pre-compensation parameters in the signal, so as to solve the problem of transceiver signal leakage, improve the isolation performance between transceivers, and improve the efficiency of signal transmission.
說明本實施例之方法如何達到上述之功效,首先請參照第一圖,以說明本實施例之方法所應用之收發機的系統架構圖,如圖所示,收發機1包括一主路訊號發射器10、一輔路訊號發射器12、一參數估測器14、一線性濾波器16、一切換器18、一主路濾波器20、一輔路濾波器22及一訊號接收器24。
Describe how the method of this embodiment achieves the above-mentioned effects. First, please refer to the first figure to illustrate the system architecture diagram of the transceiver used in the method of this embodiment. As shown in the figure, the
在本實施例中,主路訊號發射器10及輔路訊號發射器12輸出的訊號為相位偏移調變(Quadrature Phase-Shift Keying,QPSK)訊號。主路濾波器20設有消除主路訊號之通道濾波響應的通道濾波響應參數c M (n)。輔路濾波器22設有消除輔路訊號之通道濾波響應的通道濾波響應參數c A (n)。參數估測器14為處理器,用以估測主路濾波器20及輔路濾波器22的通道濾波響應參數c M (n)、c A (n)及線性濾波器16內的預補償代數q A (n)。
In this embodiment, the signals output by the main
主路訊號發射器10發送已知訓練主路訊號x M (n),主路訊號x M (n)帶有通道濾波響應參數c M (n),透過主路濾波器20補償通道濾波響應參數c M (n)後發射出補償後的主路訊號x SI (n)。輔路訊號發射器12發出已知訓練碼輔路訊號x A (n),輔路訊號x A (n)也帶有通道濾波響應參數c A (n),透過輔路濾波器22補償通道濾波響應參數c A (n)後發射出補償後的輔路訊號。
The main
訊號接收器24接收洩漏的補償後主路訊號x SI (n)及補償後輔路訊號後混合。此時若補償後輔路訊號能剛好屬於補償後主路訊號x SI (n)的反向信號,則可完美的消除洩漏的訊號,但若補償後輔路訊號無法完美的消除洩漏的補償後主路訊號,就會產生不完美輸出訊號。因此,若此參數估測器14能估算出準確的預補償參數,將有助於補償後主路訊號完全消除洩漏回訊號接收器24的主路訊號補償後主路訊號x SI (n),提升收發機的訊號收發性能。
The
收發機1應用在估測線性濾波器16的預補償代數q A (n)時,首先操作主路訊號發射器10發送主路訊號x M (n),經過主路濾波器20濾除主路訊號的通道濾波響應後發射出。同時切換器18切換使輔路訊號發射器12發出輔路訊號x A (n)不經由線性濾波器16,直接經過輔路濾波器22濾除輔路訊號的通道濾波響應後發射出。此時部分主路訊號與輔路訊號洩漏至訊號接收器,令補償後主路訊號x SI (n)與補償後輔路訊號混合進入到參數估測器14,以估測出預補償代數q A (n)後,提供給線性濾波器16補償訊號。
When the
當要對傳輸出去的訊號補償時,切換器18再進行切換,使輔路訊號進入到線性濾波器16,以補償輔路訊號,當輔路訊號輸出時,即能有效補償補償後主路訊號x SI (n),以發射完美訊號。
When it is necessary to compensate the transmitted signal, the
接著說明本實施例全雙工無線接收機之射頻消除自我干擾方法,透過本方法能估測出主路濾波器20的主路訊號之通道濾波響應參數c M (n),輔路濾波器22的輔路訊號之通道濾波響應參數c A (n),以及線性濾波器16內的預補償代數q A (n)。全雙工無線接收機之射頻消除自我干擾方法詳述如下。
Next, the radio frequency self-interference elimination method of the full-duplex wireless receiver of the present embodiment is described. Through this method, the channel filter response parameter c M ( n ) of the main channel signal of the
首先進入步驟S10,建立一射頻不完美聯合訊號模型。接著進入步驟S12,輸入主路訊號與輔路訊號至參數估測器14的射頻不完美聯合訊號模型中,以將主路訊號與輔路訊號合成,產生不完美輸出訊號。其中射頻不完美聯合訊號模型表示為式(1):
接著進入步驟S14,參數估測器14先估測主路濾波器20的主路訊號之通道濾波響應參數c M (n),輔路濾波器22的輔路訊號之通道濾波響應參數c A (n)。該步驟係根據射頻不完美聯合訊號模型及不完美輸出訊號,利用最小平方法或最小均方法對主路訊號與輔路訊號之通道濾波響應進行估測,以取得主路訊號之通道濾波響應參數及輔路訊號之通道濾波響應參數。在本實施例中,估測主路訊號之通道濾波響應參數及輔路訊號之通道濾波響應參數可使用最小平方法(Least Square,LS)、最小均方法(Least Mean Square,LMS)、遞迴最小平方法(Recursive Least Squares,RLS)、歸一化最小均方法(Normalized Least Mean Squares,NLMS)或比例歸一化最小均方法(Proportionate Normalized Least Mean Square,PNLMS)等演算法進行估測。
Then enter step S14, the
使用最小平方法(Least Square,LS)估測主路訊號之通道濾波響應參數及輔路訊號之通道濾波響應參數之步驟,詳述如下。以最小平方法(LS)來說,透過測量誤差平均值為0,使其計算出匹配的函數曲線並求得最小殘差平方和的總和。 The steps of estimating the channel filter response parameters of the main channel signal and the channel filter response parameters of the auxiliary channel signal using the least square method (Least Square, LS) are described in detail as follows. In terms of the least square method (LS), by measuring the average value of the error to be 0, it can calculate the matching function curve and obtain the sum of the minimum residual square sum.
將不完美輸出訊號r(n)轉換以矩陣r表示式(2):
接著利用最小平方法的代價函數式,估測主路訊號之通道濾波響應參數及輔路訊號之通道濾波響應參數。此法則代價函數表示為式(4):
求得與為預估值與之向量,以帶入主路濾波器20及輔路濾波器22作為主路訊號之通道濾波響應參數c M (n),輔路訊號之通道濾波響應參數c A (n)使用補償訊號。
obtain and is an estimated value and The vector is brought into the
說明使用最小均方法(Least Mean Square,LMS)估測主路訊號之通道濾波響應參數及輔路訊號之通道濾波響應參數之步驟。詳細來說,相較於LS方法以固定的濾波器設計,在無線通訊中,對於估測誤差可隨環境與時間自動調整等化器參數,適應性等化器更能滿足此需求,在此說明最小均方法如何運用迭代的方式得出適應性濾波響應值。 Describe the steps of estimating the channel filter response parameters of the main channel signal and channel filter response parameters of the auxiliary channel signal using the Least Mean Square (LMS) method. In detail, compared with the LS method with a fixed filter design, in wireless communication, the parameters of the equalizer can be automatically adjusted with the environment and time for the estimation error, and the adaptive equalizer can better meet this demand. Here Explain how the least mean method uses an iterative method to obtain the adaptive filter response value.
首先將不完美輸出訊號帶入最小均方法式,表示為式(6):J LMS =avg{e[n]e *[n]} (6)其中誤差值表示為式(7):
使用遞迴最小平方法(recursive least squares,RLS)估測主路訊號之通道濾波響應參數及輔路訊號之通道濾波響應參數之步驟,係將不完美輸出訊號帶入遞迴最小平方法式,以求得主路訊號之通道濾波響應參數及輔路訊號之通道濾波響應參數。詳細來說,RLS方法以其出色的性能與更快的收斂性聞名,遞迴最小平方法也是一種適應性濾波器算法,利用已知迭代橫向濾波器係數計算下一個時刻的迭代橫向濾波器係數。 The step of estimating the channel filter response parameters of the main channel signal and the channel filter response parameters of the auxiliary channel signal using the recursive least squares method (recursive least squares, RLS) is to bring the imperfect output signal into the recursive least squares method to obtain The channel filter response parameters of the main channel signal and the channel filter response parameters of the auxiliary channel signal are obtained. In detail, the RLS method is known for its excellent performance and faster convergence. The recursive least squares method is also an adaptive filter algorithm that uses known iterative transversal filter coefficients to calculate the iterative transversal filter coefficients at the next moment. .
遞迴最小平方法式之代價函數式表示為式(13):
同LMS方法,皆須配合環境的狀況手動調整找出合適的變數λ與δ。 Similar to the LMS method, it is necessary to manually adjust to find the appropriate variables λ and δ according to the environmental conditions.
說明使用歸一化最小均方法(Normalized Least Mean Squares,NLMS)估測主路訊號之通道濾波響應參數及輔路訊號之通道濾波響應參數之步驟,係將不完美輸出訊號帶入歸一化最小均方式,以求得該主路訊號之該通道濾波響應參數及該輔路訊號之該通道濾波響應參數。詳細步驟如下。 Explain the steps of using the Normalized Least Mean Squares (NLMS) method to estimate the channel filter response parameters of the main channel signal and the channel filter response parameters of the auxiliary channel signal, which is to bring the imperfect output signal into the normalized least mean squares method to obtain the channel filter response parameter of the main channel signal and the channel filter response parameter of the auxiliary channel signal. The detailed steps are as follows.
由LMS方法得知,估測方法須手動調整變數μ,人工調整的參數較不易精確,因此提出NLMS方法使輸入訊號的功率歸一化,以確保演算法能穩定並解決此問題。 According to the LMS method, the estimation method needs to manually adjust the variable μ , and the manually adjusted parameters are not easy to be accurate. Therefore, the NLMS method is proposed to normalize the power of the input signal to ensure the stability of the algorithm and solve this problem.
NLMS的誤差值表示為式(18):
預估的主路通道與輔路通道的通道濾波響應參數與,用矩陣形式表示成,x M (n)與x A (n)用矩陣形式表示成X=[x M (n)x A (n)]。 Estimated channel filter response parameters of the main channel and auxiliary channel and , expressed in matrix form as , x M ( n ) and x A ( n ) are expressed in matrix form as X=[ x M ( n ) x A ( n )].
接著歸一化最小均方式之代價函數式,如式(19):
使用比例歸一化最小均方法(proportionate normalized least mean square,PNLMS)對主路訊號與輔路訊號之通道濾波響應進行估測。比例歸一化最小均方法與NLMS相比,在反射波路徑稀疏時,PNLMS具有非常快的初始收斂與追蹤,若脈衝響應較為分散時,PNLMS的收斂速度就不及NLMS,由上述得知PNLMS易受到環境所影響。
歸一化最小均方法的代價函數表示為式(24):
在上述步驟S14通過最小平方法、最小均方法、遞迴最小平方法、歸一化最小均方法或比例歸一化最小均方法估測出主路訊號之通道濾波響應參數及輔路訊號之通道濾波響應參數後,即可提供主路濾波器20及輔路濾波器22使用,濾除主路訊號與輔路訊號中的通道濾波響應。
In the above step S14, the channel filter response parameters of the main channel signal and the channel filter of the auxiliary channel signal are estimated by the least square method, the least mean method, the recursive least square method, the normalized least mean method or the proportional normalized least mean method After responding to the parameters, it can be provided to the
進入步驟S16估測預補償參數。步驟S16係參數估測器14根據主路訊號之通道濾波響應參數及輔路訊號之通道濾波響應參數,補償射頻不完美聯合訊號模型之通道濾波響應,以估算測出預補償參數。
Go to step S16 to estimate the pre-compensation parameters. Step S16 is that the
詳細來說,參數估測器14在估算預補償參數時,先加入預補償代數至射頻不完美聯合訊號模型,以建立理想射頻聯合訊號模型。其中理想射頻聯合訊號模型表示為式(30):
接著帶入上述步驟S14估測出的主路訊號之通道濾波響應參數及輔路訊號之通道濾波響應參數至理想射頻聯合訊號模型中,以估測出預補償參數。其演算步驟係將轉換為矩陣形,表示為式(31):c M =-C A q A (31)q A 為q A (n)的向量表示,C A 為c A (n)的托普利茲(Toeplitz)矩陣表示。接著使用偽逆矩陣(Pseudoinverse)轉換q A ,以估測出預補償參數q A (n),偽逆矩陣的q A 表示為式(32):q A =-(C A H C A )-1 C A H c M (32) Then, the channel filter response parameters of the main channel signal and the channel filter response parameters of the auxiliary channel signal estimated in the above step S14 are brought into the ideal RF joint signal model to estimate the pre-compensation parameters. Its calculation steps will be Converted to matrix form, expressed as formula (31): c M =- C A q A (31) q A is the vector representation of q A ( n ), C A is the Toeplitz of c A ( n ) matrix representation. Then use the pseudo-inverse matrix (Pseudoinverse) to convert q A to estimate the pre-compensation parameter q A ( n ). The pseudo-inverse matrix q A is expressed as formula (32): q A =-( C A H C A ) - 1 C A H c M (32)
最後進入步驟S18,利用預補償參數補償不完美輸出訊號。透過上述方法即可得到主路訊號之通道濾波響應參數c M (n),輔路訊號之通道濾波響應參數c A (n)以及預補償參數q A ,故本實施例可將上述補償參數提供給能消除射頻洩漏之收發機1,以有效補償不完美輸出訊號。
Finally, enter step S18, using the pre-compensation parameters to compensate the imperfect output signal. The channel filter response parameter c M ( n ) of the main channel signal, the channel filter response parameter c A ( n ) of the auxiliary channel signal and the pre-compensation parameter q A can be obtained through the above method, so this embodiment can provide the above compensation parameters to
在補償不完美輸出訊號時,主路訊號發射器10發射主路訊號x M (n)經過主路濾波器20,以濾除主路訊號的通道濾波響應。同時輔路訊號發射器12發射輔路訊號x A (n),此時切換器18切換輔路訊號x A (n)進入線性濾波器16,以透過線性濾波器16的預補償參數q A 來補償輔路訊號,其再進入到輔路濾波器22,以補償輔路訊號的通道濾波響應。因此帶有預補償參數的輔路訊號就能完全消除部分洩漏的主路訊號,達到主動射頻洩漏消除之技術。
When compensating the imperfect output signal, the main
請參照第三圖,其為經本實施例所應用之方法所產生的實驗數據比較頻譜圖,藉由10兆赫(MHz)的單載波訊號可從頻譜圖上直接觀測本實施例之方法所估測預補償參數q A 是否有效抑制洩漏的主路訊號,且可透過計算執行主動射頻消除前後強度比值。由第四圖能明顯看出預補償前洩漏的主路訊號明顯突出,但預補償後已完全被削除。 Please refer to the third figure, which is a comparison spectrogram of experimental data generated by the method applied in this embodiment. The 10 megahertz (MHz) single carrier signal can be directly observed from the spectrogram and estimated by the method of this embodiment Whether the pre-compensation parameter q A effectively suppresses the leaked main channel signal, and can be calculated by calculating the intensity ratio before and after active radio frequency cancellation. From Figure 4, it can be clearly seen that the leaked main channel signal is prominent before pre-compensation, but it has been completely eliminated after pre-compensation.
然而本發明除了上述實施例所示,可針對通道濾波響應及不完美輸出訊號進行補償之外,更可針對寬頻射頻不完美因此進行補償,在本實施例中,寬頻射頻不完美因子所指的是,當基頻訊號經由射頻發送時,需要經過振幅/相位(In-phase/Quadrature,I/Q)調變器將訊號載送至高頻,其伴隨著射頻元件與震盪電路的誤差,因此產生振幅不平衡及相位不平衡,也就是IQ不平衡。因此,本實施例更針對射頻具有IQ不平衡情境下,與通道濾波響應共存,此響應將會併入IQ不平衡進行聯合估測,詳述如下。 However, in addition to the above embodiment, the present invention can compensate for channel filter response and imperfect output signal, and can also compensate for broadband radio frequency imperfections. In this embodiment, the broadband radio frequency imperfection factor refers to Yes, when the baseband signal is sent through the radio frequency, it needs to pass through the amplitude/phase (In-phase/Quadrature, I/Q) modulator to carry the signal to the high frequency, which is accompanied by the error of the radio frequency component and the oscillator circuit, so Amplitude imbalance and phase imbalance are generated, that is, IQ imbalance. Therefore, this embodiment is more aimed at the coexistence of channel filter response and IQ imbalance in the situation where the radio frequency has IQ imbalance, and the response will be incorporated into the IQ imbalance for joint estimation, as detailed below.
本實施例所應用的系統架構以及主要步驟流程與上述實施例相同,故說明本實施例時,仍以第一圖與第二圖配合說明。唯一不同在於主路濾波器20與輔路濾波器22增加了補償訊號的主路訊號與輔路訊號的振幅(In-phase,I)不平衡參數及相位(Quadrature,Q)不平衡參數,
及主路訊號與輔路訊號的振幅通道的振幅通道濾波響應參數,以及主路訊號與輔路訊號的相位通道的相位通道濾波響應參數。
The system architecture and main steps of this embodiment are the same as those of the above-mentioned embodiments, so when describing this embodiment, the first and second figures are still used for illustration. The only difference is that the
本實施例在估測參數時亦與上述實施例相同,在參數估測器14中進行參數估測。首先進步驟S10,在參數估測器14中建立一射頻不完美聯合訊號模型。輸入主路訊號與輔路訊號至射頻不完美聯合訊號模型中,以將主路訊號與輔路訊號合成,產生不完美輸出訊號。其中射頻不完美聯合訊號模型表示為式(33):
進入步驟S14,參數估測器14根據射頻不完美聯合訊號模型及不完美輸出訊號,利用最小平方法或最小均方法對主路訊號與輔路訊號之通道濾波響應進行估測,以取得主路訊號之通道濾波響應參數及輔路訊號之通道濾波響應參數。在本實施例中,參數估測器14更對主路訊號與輔路訊號的振幅(In-phase,I)不平衡參數及相位(Quadrature,Q)不平衡參數,及主路訊號與輔路訊號的振幅通道的振幅通道濾波響應
參數,以及主路訊號與輔路訊號的相位通道的相位通道濾波響應參數進行估測。
Entering step S14, the
本實施例中估測主路訊號與輔路訊號的振幅通道的振幅通道濾波響應參數,以及主路訊號與輔路訊號的相位通道的相位通道濾波響應參數可使用最小平方法(LS)、最小均方法(LMS)、遞迴最小平方法(RLS)、歸一化最小均方法(NLMS)或比例歸一化最小均方法(PNLMS)進行估測。 In this embodiment, the least square method (LS) and the least average method can be used to estimate the amplitude channel filter response parameters of the amplitude channel of the main channel signal and the auxiliary channel signal, and the phase channel filter response parameters of the phase channel of the main channel signal and the auxiliary channel signal. (LMS), recursive least squares (RLS), normalized least mean (NLMS) or proportional normalized least mean (PNLMS).
首先說明使用最小平方法(Least Square,LS)對主路訊號與輔路訊號的振幅通道的振幅通道濾波響應參數,以及主路訊號與輔路訊號的相位通道的相位通道濾波響應參數進行估測之方法。 Firstly, the method of estimating the amplitude channel filter response parameters of the amplitude channels of the main channel signal and the auxiliary channel signal and the phase channel filter response parameters of the phase channel of the main channel signal and the auxiliary channel signal by using the least square method (Least Square, LS) .
針對未知的主路通道與輔路通道的通道濾波響應參數h M,±(n)與h A,±(n),將接收訊號r(n)改為矩陣r表示,採用最小平方法,以Least Square(LS)方法來說,透過測量誤差平均值為0,使其計算出匹配的函數曲線並求得最小殘差平方和的總和。將不完美輸出訊號轉換以矩陣表示為式(34):
使用最小均方法(Least Mean Square,LMS)對主路訊號與輔路訊號的振幅通道的振幅通道濾波響應參數,以及主路訊號與輔路訊號的相位通道的相位通道濾波響應參數進行估測之方法詳述如下。 Using the Least Mean Square (LMS) method to estimate the amplitude channel filter response parameters of the amplitude channel of the main channel signal and the auxiliary channel signal, and the phase channel filter response parameters of the phase channel of the main channel signal and the auxiliary channel signal. described below.
相較於LS方法以固定的濾波器設計,在無線通訊中,對於估測誤差可隨環境與時間自動調整等化器參數,適應性等化器更能滿足此需求,在此介紹最小平方法如何運用迭代的方式得出適應性濾波響應值。 Compared with the LS method with a fixed filter design, in wireless communication, the parameters of the equalizer can be automatically adjusted according to the environment and time for the estimation error, and the adaptive equalizer can better meet this demand. The least square method is introduced here. How to use the iterative method to obtain the adaptive filter response value.
最小均方法之代價函數如式(38):
J LMS =avg{e[n]e *[n]} (38)其中誤差值e[n]表示為式(39):
對上式(38)各代價函數微分,以估測出該主路訊號之該通道濾波響應參數,及該輔路訊號之該通道濾波響應參數,並簡化成式(41):
使用遞迴最小平方法(recursive least squares,RLS)對主路訊號與輔路訊號的振幅通道的振幅通道濾波響應參數,以及主路訊號與輔路訊號的相位通道的相位通道濾波響應參數進行估測,係將不完美輸出訊號帶入遞迴最小平方法式,以求得主路訊號之通道濾波響應參數及該輔路訊號之該通道濾波響應參數。詳細來說,RLS方法以其出色的性能與更快的收斂性聞名,遞迴最小平方法也是一種適應性濾波器算法,利用已知迭代橫向濾波器係數計算下一個時刻的迭代橫向濾波器係數。
遞迴最小平方法之價函數如式(42):
使用歸一化最小均方法(Normalized Least Mean Squares,MLMS)對主路訊號與輔路訊號的振幅通道的振幅通道濾波響應參數,以及主路訊號與輔路訊號的相位通道的相位通道濾波響應參數進行估測。其係將不完美輸出訊號帶入歸一化最小均方式,以求得主路訊號之通道濾波響應參數及輔路訊號之通道濾波響應參數。詳細來說,由LMS方 法得知,估測方法須手動調整變數μ,人工調整的參數較不易精確,因此提出NLMS方法使輸入訊號的功率歸一化,以確保演算法能穩定並解決此問題。 Use the normalized least mean method (Normalized Least Mean Squares, MLMS) to estimate the amplitude channel filter response parameters of the amplitude channel of the main channel signal and the auxiliary channel signal, and the phase channel filter response parameters of the phase channel of the main channel signal and the auxiliary channel signal. Measurement. It brings the imperfect output signal into the normalized minimum average method to obtain the channel filter response parameters of the main channel signal and the channel filter response parameters of the auxiliary channel signal. In detail, from the LMS method, it is known that the estimation method must manually adjust the variable μ , and the manually adjusted parameters are not easy to be accurate. Therefore, the NLMS method is proposed to normalize the power of the input signal to ensure the stability of the algorithm and solve this problem. .
NLMS的誤差值表示為式(47):
使用比例歸一化最小均方法對主路訊號與輔路訊號的振幅通道的振幅通道濾波響應參數,以及主路訊號與輔路訊號的相位通道的相位通道濾波響應參數進行估測。與NLMS相比,在反射波路徑稀疏時,PNLMS具有非常快的初始收斂與追蹤,若脈衝響應較為分散時,PNLMS的收斂速度就不及NLMS,由上述得知PNLMS易受到環境所影響。
比例歸一化最小均方法之代價函數表示為式(53):
P(n)=I-G(n-1)X(n)[X T (n)G(n-1)X(n)]-1 X T (n)
其中誤差值e[n]及主路訊號與輔路訊號的振幅通道的振幅通道濾波響應參數,以及主路訊號與輔路訊號的相位通道的相位通道濾波響應參數表示為式(57):
上述步驟S14通過最小平方法、最小均方法、遞迴最小平方法、歸一化最小均方法或比例歸一化最小均方法估測出主路訊號與輔路訊號的振幅通道的振幅通道濾波響應參數,以及主路訊號與輔路訊號的相位通道的相位通道濾波響應參數進行估測後,即可提供主路濾波器20及輔路濾波器22使用,濾除主路訊號與輔路訊號中的IQ不平衡及通道濾波響應。
The above step S14 estimates the amplitude channel filter response parameters of the amplitude channels of the main channel signal and the auxiliary channel signal by the least square method, the least mean method, the recursive least square method, the normalized least mean method or the proportional normalized least mean method , and the phase channel filter response parameters of the phase channel of the main channel signal and the auxiliary channel signal are estimated, and can be used for the
接著估測預補償參數。參步驟S16,根據主路訊號之通道濾波響應參數及輔路訊號之通道濾波響應參數,補償射頻不完美聯合訊號模型之通道濾波響應,以估算測出預補償參數。在本實施例中係對主路訊號與輔路訊號的振幅通道的振幅預補償參數,以及相位通道的相位預補償參數進行估測。參數估測器14在估算預補償參數時,會加入振幅預補償代數及相位預補償代數至射頻不完美聯合訊號模型,以建立理想射頻聯合訊號模型。其中理想射頻聯合訊號模型表示為,式(58):
接著帶入上述步驟S14估測出的振幅通道濾波響應參數、相位通道濾波響應參數、振幅不平衡參數及相位不平衡參數至理想射頻聯合訊號模型中,以估測出振幅預補償參數及相位預補償參數。詳細來說,將理想射頻聯合訊號模型轉換為矩陣,其表示為式(59):
最後進入步驟S18,利用振幅預補償參數及相位預補償參數,補償不完美輸出訊號。透過上述方法即可得到主路訊號與輔路訊號的振幅(In-phase,I)不平衡參數及相位(Quadrature,Q)不平衡參數,及主路訊號與輔路訊號的振幅通道的振幅通道濾波響應參數、,以及主路訊號與輔路訊號的相位通道的相位通道濾波響應參數、進行估測,以及振幅預補償參數w 1、相位預補償參數w 2,故本實施例可將上述補償參數提供給能消除射頻洩漏之收發機,以有效補償不完美輸出訊號。 Finally, enter step S18, using amplitude pre-compensation parameters and phase pre-compensation parameters to compensate the imperfect output signal. Through the above method, the amplitude (In-phase, I) unbalance parameter and phase (Quadrature, Q) unbalance parameter of the main channel signal and the auxiliary channel signal, and the amplitude channel filter response of the amplitude channel of the main channel signal and the auxiliary channel signal can be obtained parameter , , and the phase channel filter response parameters of the phase channel of the main channel signal and the auxiliary channel signal , Estimated, amplitude pre-compensation parameter w 1 , phase pre-compensation parameter w 2 , so this embodiment can provide the above compensation parameters to the transceiver capable of eliminating radio frequency leakage, so as to effectively compensate the imperfect output signal.
在補償不完美輸出訊號時,主路訊號發射器10發射主路訊號x M (n)經過主路濾波器20,以濾除主路訊號的振幅(In-phase,I)不平衡參數及相位(Quadrature,Q)不平衡參數,及主路訊號的振幅通道的振幅通道濾波響應參數,及主路訊號的相位通道的相位通道濾波響應參數。同時輔路訊號發射器12發射輔路訊號x A (n),此時切換器18切換輔路訊號x A (n)進入線性濾波器16,以透過線性濾波器16的振幅預補償參數w 1、相位預補償參數w 2來補償輔路訊號,其再進入到輔路濾波器22,以濾除輔路訊號的振幅(In-phase,I)不平衡參數及相位(Quadrature,Q)不平衡參數,及輔路訊號的振幅通道的振幅通道濾波響應參數,及輔路訊號的相位通道的相位通道濾波響應參數。因此帶有預補償參數的輔路訊號就能完全消除部分洩漏的主路訊號,達到主動射頻洩漏消除之技術。
When compensating the imperfect output signal, the main
請參照第四圖,其為經本實施例所應用之方法所產生的實驗數據比較頻譜圖,藉由10兆赫(MHz)的單載波訊號可從頻譜圖上直接觀測本實施例之方法所估測預振幅預補償參數w 1、相位預補償參數w 2是否有效抑制洩漏的主路訊號,且可透過計算執行主動射頻消除前後強度比值。由第四圖能明顯看出預補償前洩漏的主路訊號明顯突出,但預補償後已完全被削除。 Please refer to the fourth figure, which is a comparison spectrogram of experimental data generated by the method applied in this embodiment. The 10 megahertz (MHz) single carrier signal can be directly observed from the spectrogram and estimated by the method of this embodiment Whether the pre-amplitude pre-compensation parameter w 1 and the phase pre-compensation parameter w 2 can effectively suppress the leaked main channel signal can be calculated by calculating the intensity ratio before and after active radio frequency cancellation. From Figure 4, it can be clearly seen that the leaked main channel signal is prominent before pre-compensation, but it has been completely eliminated after pre-compensation.
綜上所述,本發明能估測出訊號中的通道濾波響應以及預補償參數,以解決收發機訊號洩漏的問題,提升收發機間的隔離度性能,提升訊號傳遞效益。同時能估測出訊號中的IQ不平衡的問題,以補償訊號,提升訊號傳遞效益。 To sum up, the present invention can estimate the channel filter response and pre-compensation parameters in the signal, so as to solve the problem of transceiver signal leakage, improve the isolation performance between transceivers, and improve the efficiency of signal transmission. At the same time, it can estimate the IQ imbalance problem in the signal to compensate the signal and improve the efficiency of signal transmission.
唯以上所述者,僅為本發明之較佳實施例而已,並非用來限定本發明實施之範圍。故即凡依本發明申請範圍所述之特徵及精神所為之均等變化或修飾,均應包括於本發明之申請專利範圍內。 The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the scope of the present invention. Therefore, all equivalent changes or modifications based on the features and spirit described in the scope of the application of the present invention shall be included in the scope of the patent application of the present invention.
S10~S18:步驟 S10~S18: steps
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Citations (5)
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US20080008258A1 (en) * | 2006-07-05 | 2008-01-10 | Yasuhiko Tanabe | Wireless receiving apparatus and method |
US20090213944A1 (en) * | 2008-02-25 | 2009-08-27 | Grant Stephen J | Receiver Parametric Covariance Estimation for Precoded MIMO Transmissions |
TW201724818A (en) * | 2015-12-24 | 2017-07-01 | 元智大學 | United estimation pre-compensation method for solving imperfection in downstream transmission system capable of transmitting a more perfect signal by compensating for a receiving signal in advance on a transmitting end |
US20170353288A1 (en) * | 2015-07-16 | 2017-12-07 | LGS Innovations LLC | Self-Interference Channel Estimation System and Method |
US20200351072A1 (en) * | 2012-05-13 | 2020-11-05 | Amir Keyvan Khandani | Full duplex wireless transmission with self-interference cancellation |
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Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20080008258A1 (en) * | 2006-07-05 | 2008-01-10 | Yasuhiko Tanabe | Wireless receiving apparatus and method |
US20090213944A1 (en) * | 2008-02-25 | 2009-08-27 | Grant Stephen J | Receiver Parametric Covariance Estimation for Precoded MIMO Transmissions |
US20200351072A1 (en) * | 2012-05-13 | 2020-11-05 | Amir Keyvan Khandani | Full duplex wireless transmission with self-interference cancellation |
US20170353288A1 (en) * | 2015-07-16 | 2017-12-07 | LGS Innovations LLC | Self-Interference Channel Estimation System and Method |
TW201724818A (en) * | 2015-12-24 | 2017-07-01 | 元智大學 | United estimation pre-compensation method for solving imperfection in downstream transmission system capable of transmitting a more perfect signal by compensating for a receiving signal in advance on a transmitting end |
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