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CN-122026941-A - Transmitter leakage signal suppression method and suppression circuit for multichannel transceiver

CN122026941ACN 122026941 ACN122026941 ACN 122026941ACN-122026941-A

Abstract

The invention discloses a transmitter leakage signal suppression method and a suppression circuit of a multichannel transceiver. The invention opens the multi-channel transmitting channels of the transmitter one by one, but not partially or completely simultaneously, and designs a self-adaptive leakage modeling and counteracting mechanism based on the known transmitting baseband sequence by matching with the transimpedance amplification and analog-digital conversion of each channel receiving channel of the receiver. The self-adaptive estimation of the emission leakage component is realized by performing correlation processing on the received signal and the emission baseband sequence by fully utilizing the known and reproducible characteristics of the emission baseband sequence in the radar, and corresponding compensation signals are generated for cancellation. When one path of transmitting channel is opened, the aim of iterative cancellation of the leakage signal of the transmitter is achieved. Therefore, under the condition that the performance of the receiving front end is basically not affected, the leakage signal of the transmitter carried in the radio wave received by the receiver can be restrained, and the accuracy of radio wave ranging or speed measuring is greatly improved.

Inventors

  • HU YIZHE
  • DENG JUNCHENG

Assignees

  • 中国科学技术大学

Dates

Publication Date
20260512
Application Date
20260408

Claims (10)

  1. 1. A method for transmitter leakage signal suppression in a multi-channel transceiver, comprising: starting multiple paths of transmitting channels of a transmitter one by one; The transmission signal R i (t) which is newly added along with the time t and is changed due to the opening of any ith transmission channel carries the leakage signal of the corresponding transmission channel, and a digital receiving sequence S i (n) with a transmission leakage component is formed after transimpedance amplification and analog-digital conversion, wherein n represents the nth sampling moment for sampling R i (t); Designing a digital compensation sequence C i (n) according to known transmission baseband sequences P i (n) and S i (n), wherein C i (n)=A i (k i )•P i (n) is made, ,A i (k i )=A i (k i -1)+μ•f(S i (n)•P i (n)),A i (k i )、A i (k i -1) is the iteration weight of the kth i time and the kth i -1 time of iteration when C i (n) is constructed, A i (0) is the initial iteration weight, mu is the iteration step size, f () is a symbol function or an equivalent mapping function, judging whether the sampling amplitude of S i (n) is smaller than the minimum sampling effective bit of the analog-to-digital conversion, if yes, outputting the current C i (n), starting a next transmission channel, otherwise, returning to the previous step to perform the next iteration on C i (n); C i (n) is subjected to digital-to-analog conversion and transconductance amplification to form an analog compensation signal C i (t) which is negatively fed back to R i (t),S i (n) to form a digital receiving sequence with the cancellation of the emission leakage component At this time, the transmission signal R (t) and the corresponding digital receiving sequence S (n) received by each receiving channel of the receiver are respectively: , 。
  2. 2. the method for transmitter leakage signal suppression of a multi-channel transceiver of claim 1, the method is characterized in that the initial iteration weight defaults to 0.
  3. 3. The method of transmitter leakage signal suppression for a multi-channel transceiver of claim 1, wherein the transimpedance amplification is implemented by a transimpedance amplifier; and/or the analog-to-digital conversion is realized by an analog-to-digital converter ADC.
  4. 4. The method of transmitter leakage signal suppression for a multi-channel transceiver of claim 1, wherein the digital-to-analog conversion is implemented by a digital-to-analog converter DAC; and/or, the transconductance amplification is realized by a transconductance amplifier; And/or the negative feedback is realized by a subtracter.
  5. 5. A radio wave distance or speed measuring method of PMCW car radar, characterized in that it samples the transmitter leakage signal suppressing method of the multi-channel transceiver according to any one of claims 1 to 4, suppresses the transmitter leakage signal carried in the radio wave received by the receiver, and suppresses the processed radio wave for distance or speed measurement of the radio wave.
  6. 6. A transmitter leakage signal suppression circuit for a multichannel transceiver, comprising: The self-adaptive suppression processor is used for starting multiple transmission channels of the transmitter one by one and designing a digital compensation sequence C i (n) according to a known transmission baseband sequence P i (n) and a digital receiving sequence S i (n); S i (t) is a transmission signal R i (t) which is newly added due to the opening of any ith transmission channel and changes along with time t, carries leakage signals of corresponding transmission channels, forms a digital receiving sequence with a transmission leakage component after transimpedance amplification and analog-to-digital conversion, and n represents an nth sampling time for sampling R i (t); C i (n) is that C i (n)=A i (k i )•P i (n) is made, ,A i (k i )=A i (k i -1)+μ•f(S i (n)•P i (n)),A i (k i )、A i (k i -1) in the formula is respectively the iteration weight of the kth i and the kth i -1 iteration when C i (n) is constructed, A i (0) is the corresponding initial iteration weight, mu is the iteration step length, f () is a symbol function or an equivalent mapping function, whether the sampling amplitude of S i (n) is smaller than the minimum sampling valid bit of the analog-to-digital conversion is judged, if yes, the current C i (n) is output, the next transmission channel is started, and otherwise, the next iteration is carried out on the C i (n) by returning to the previous step; a digital-to-analog converter for digital-to-analog converting C i (n) to form an analog compensation signal C i (t); A transconductance amplifier for transconductance amplifying C i (t), A subtracter for negatively feeding back C i (t) after transconductance amplification to R i (t),S i (n) to form a digital receiving sequence with cancellation of the emission leakage component At this time, the transmission signal R (t) and the corresponding digital receiving sequence S (n) received by each receiving channel of the receiver are respectively: , 。
  7. 7. the transmitter leakage signal suppression circuit of the multi-channel transceiver of claim 6, wherein the initial iteration weight defaults to 0.
  8. 8. The transmitter leakage signal suppressing circuit of a multi-channel transceiver of claim 6, wherein the digital-to-analog converter is a digital-to-analog converter of 6 bits binary codes + bits hot codes.
  9. 9. The transmitter leakage signal suppressing circuit of a multi-channel transceiver of claim 6, wherein the transconductance amplifier is a transconductance amplifier with a low pass filter.
  10. 10. A multi-channel transceiver comprising a multi-channel transmitter and a multi-channel receiver, each receive channel of the receiver comprising: a transimpedance amplifier for transimpedance amplifying a transmission signal R i (t) which is coupled with a leakage signal and changes with time t; An analog-to-digital converter for analog-to-digital converting the transimpedance-amplified R i (t) and forming a transmission sequence S i (n) having a transmission leakage component, n representing an nth sampling time at which the R i (t) is sampled; Characterized by further comprising: The transmitter leakage signal suppressing circuit of a multi-channel transceiver as claimed in any one of claims 6 to 9, wherein the output of the analog-to-digital converter is negative fed back to the input of the transimpedance amplifier after the transmitter leakage signal is suppressed.

Description

Transmitter leakage signal suppression method and suppression circuit for multichannel transceiver Technical Field The present invention relates to a method for suppressing a transmitter leakage signal and a suppressing circuit thereof, and more particularly, to a method for suppressing a transmitter leakage signal of a multi-channel transceiver and a suppressing circuit thereof, a method for measuring a radio wave distance or a speed of PMCW car radars using the suppressing method, a multi-channel transceiver using the suppressing circuit, and a multi-transmission multi-reception radar system using the multi-channel transceiver. Background PMCW the automobile radar can be applied to PMCW multi-transmission multi-reception radar systems, and distance measurement or speed measurement of radio waves can be achieved according to the transmitted and received wireless signals. PMCW (Phase-Modulated Continuous Wave, phase-coded continuous wave) radar is a continuous wave radar system that is Phase modulated by a pseudo-random code (PRN/PN code). The basic idea is to modulate a high-speed pseudo-random sequence onto the carrier phase, to achieve distance measurement by correlation processing (correlation), and to obtain velocity information by doppler processing. Compared with the traditional FMCW radar, PMCW has the advantages of strong anti-interference capability, support of MIMO orthogonal coding, high distance resolution and the like, and therefore, the method is widely focused in the new generation of 4D imaging automobile millimeter wave radar. In PMCW multiple-transmit multiple-receive radar systems, multiple transmit channels operate simultaneously or quasi-simultaneously, and transmit signals leak to receive channels under high power, wide bandwidth conditions through multiple paths such as insufficient antenna isolation, on-chip parasitic coupling, package interconnection, substrate coupling, and the like, forming transmit leakage interference. The leakage signal has the characteristics of large amplitude and strong correlation, and a remarkable correlation peak value is easy to form at a receiving end, so that weak target echo is submerged, and the dynamic range and detection performance of the system are reduced. In the prior art, aiming at the problem of emission leakage in PMCW radar transceivers, a leakage suppression scheme based on baseband correlation cancellation, namely a single-channel baseband transmitter leakage suppression circuit, has been proposed. The scheme utilizes the known transmitting baseband signal to carry out correlation operation on the signal output by the mixer in a receiving link, and the cancellation of the transmitting leakage component is realized by carrying out weighted duplication on the transmitting baseband sequence and injecting the weighted duplication into a mixer output node or a post-stage baseband processing path. The method enables leakage components highly correlated with a transmission sequence to be effectively restrained in a baseband domain through correlation and integration operation, and target echo signals are reserved. The scheme has the advantages that the inner part of the inhibition loop route receiving channel is self-closed, no extra radio frequency isolation device is needed, the structure is relatively simple, the working mechanism is clear, the amplitude and phase errors to a certain extent can be self-adaptively compensated, and the scheme is suitable for single-shot multi-shot application scenes. However, this scheme essentially relies on correlation modeling and weighted cancellation of the single path transmit baseband signal, and when multiple transmitters are present in the system to operate simultaneously, the baseband sequences, amplitudes, phases, and leakage path characteristics of the different transmit channels are independent of each other, and the leakage signal superimposed at the receiving end no longer satisfies the single correlation model assumption. Under the multi-transmission multi-reception radar architecture, the scheme is difficult to effectively distinguish and independently inhibit multi-transmission leakage at the same time, so that the inhibition effect is obviously reduced, and even the normal operation cannot be realized. Therefore, the applicability of this type of approach in multi-channel PMCW radar transceivers is significantly limited. In order to solve the problem of simultaneous leakage of multiple paths of transmission signals in a multiple-transmission multiple-reception radar system, a multi-channel radio frequency front-end transmitter leakage suppression circuit which is a multi-channel transmission leakage suppression scheme is also provided in the prior art. The scheme introduces copies of multipath emission signals into a receiver architecture, models and counteracts leakage components of all emission channels at a radio frequency or intermediate frequency front end, and therefore simultaneous su