A signal demodulation method, medium, chip, circuit, device and equipment

Abstract

The application relates to the technical field of radar demodulation, and discloses a signal demodulation method, a medium, a chip, a circuit, a device and equipment. The signal demodulation method comprises the following steps: determining a target angle according to echo signals received through different receiving channels; generating compensation signals of transmission signals of each transmission channel according to the target angle and a phase relationship between the transmission signals of the different transmission channels; and compensating the echo signals received by each receiving channel according to the compensation signals, so as to determine a demodulation signal corresponding to a situation that each transmission channel corresponds to a transmission channel sequence when the receiving signal energy is maximum. The signal demodulation can be efficiently and reliably performed.

Description

Technical Field

[0001] This application relates to the field of radar demodulation technology, and in particular to a signal demodulation method, medium, chip, circuit, device and equipment. Background Technology

[0002] In DDM (Doppler-Division Multiplexing) modulation, the received signals from different transmitting channels targeting the same object in the echo signal will have a specific inter-pulse Doppler frequency relationship, thus allowing the determination of the correspondence between the signal and the antenna. DDM and FDM (Frequency-Division Multiplexing) have similar characteristics, but because inter-pulse phase modulation has a larger time scale than intra-pulse frequency modulation, DDM modulation is easier to implement (and offers other signal-level advantages), making it an important development direction for signal modulation in radar.

[0003] However, the demodulation of DDM modulated transmitted signals at the receiver is currently not efficient or reliable enough. Summary of the Invention

[0004] This application provides a signal demodulation method, medium, chip, circuit, device, and equipment that can perform signal demodulation efficiently and reliably.

[0005] According to some embodiments of this application, a first aspect of this application provides a signal demodulation method, including: determining a target angle based on echo signals received through different receiving channels; generating a compensation signal for the transmitted signal of each transmitting channel based on the phase relationship between the target angle and the transmitted signals transmitted through different transmitting channels; and compensating the echo signals received by each receiving channel based on the compensation signal to determine the demodulation signal corresponding to the transmitting channel sequence when the received signal energy of each transmitting channel is at its maximum.

[0006] In some embodiments, generating a transmission signal compensation signal for each transmission channel based on the phase relationship between the target angle and the transmission signals transmitted through different transmission channels includes: generating a compensation signal for each transmission channel based on the transmission signal of the target transmission channel, according to the phase relationship between the target angle and the transmission signals transmitted through different transmission channels.

[0007] In some embodiments, the step of compensating the echo signals received by each receiving channel according to the compensation signal to determine the demodulated signal corresponding to the transmission channel sequence when the received signal energy is at its maximum includes: compensating the echo signals received by each receiving channel according to the compensation signal corresponding to the target transmission channel to determine the demodulated signal corresponding to the target transmission channel when the received signal energy is at its maximum; and determining the demodulated signals corresponding to other transmission channels besides the target transmission channel according to the phase relationship between the demodulated signal corresponding to the target transmission channel and the transmission signals transmitted by different transmission channels.

[0008] In some embodiments, the target transmission channel is a transmission channel in which the transmitted signal is not modulated.

[0009] In some embodiments, generating the compensation signal for each transmission channel based on the transmission signal of the target transmission channel according to the phase relationship between the target angle and the transmission signals transmitted by different transmission channels includes: determining the phase offset that each transmission channel needs to compensate for based on the phase relationship between the target angle and the transmission signals transmitted by different transmission channels, and generating the compensation signal for each transmission channel based on the transmission signal of the target transmission channel.

[0010] In some embodiments, the step of generating the compensation signal for each transmission channel based on the target transmission channel, determined according to the phase offset to be compensated for by each transmission channel based on the phase relationship between the target angle and the transmission signals transmitted through different transmission channels, is achieved by the following expression: comp[tx]=e^[-j×φ(tx+tone_{candidate},θ)]; where comp[tx] is the compensation signal corresponding to the transmission channel with the sequence number tx, tone_{candidate} is the transmission channel offset determined according to the phase relationship between the transmission signals transmitted through different transmission channels, and θ is the target angle.

[0011] In some embodiments, the step of compensating the echo signals received by each receiving channel according to the compensation signal to determine the demodulated signal corresponding to the transmission channel sequence when the received signal energy of each transmitting channel is at its maximum includes: performing fast Fourier transform, multiplication, and inverse fast Fourier transform on the compensation signal and the echo signals received by each receiving channel in the transmission channel dimension to generate the demodulated signal corresponding to the transmission channel sequence when the received signal energy of each transmitting channel is at its maximum.

[0012] In some embodiments, the fast Fourier transform, multiplication, and inverse fast Fourier transform of the compensation signal and the echo signals received by each receiving channel in the transmit channel dimension are implemented by the following expression: convolution(comp[tx], sig[tx, rx]) = ifft(fft_{tx}(comp[tx])×fft_{tx}(sig[tx, rx])); where convolution(comp[tx], sig[tx, rx]) is the demodulated signal corresponding to the transmit channel with index tx in the receive channel with index rx, comp[tx] is the compensation signal corresponding to the transmit channel with index tx, sig[tx, rx] is the signal portion of the signal transmitted by the transmit channel with index tx applied to the echo signal received by the receive channel with index rx, and ifft(fft_{tx}) is the signal portion of the echo signal received by the receive channel with index rx. (comp[tx])×fft_{tx}(sig[tx, rx])) performs an inverse Fast Fourier Transform on the result of fft_{tx}(comp[tx])×fft_{tx}(sig[tx, rx]), fft_{tx}(comp[tx]) performs a Fast Fourier Transform on the comp[tx] signal in the transmit channel dimension, and fft_{tx}(sig[tx, rx]) performs a Fast Fourier Transform on the sig[tx, rx] signal in the transmit channel dimension.

[0013] In some embodiments, the transmitted signals from the different transmission channels are phase-modulated based on Doppler multiplexing.

[0014] In some embodiments, the phase of the transmitted signals from the different transmission channels changes linearly in a stepwise manner.

[0015] In some embodiments, the phase of the transmitted signals from the different transmission channels is modulated at 0° or 180°, and the periods of the phase modulation sequences are unequal and factored to each other, and the period sequences of the phase modulation sequences of any two transmission channels are orthogonal.

[0016] According to some embodiments of this application, a second aspect of this application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the signal demodulation method as described in any of the preceding claims.

[0017] According to some embodiments of this application, a third aspect of this application also provides a radar chip, including: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to perform the signal demodulation method as described in any of the preceding claims.

[0018] According to some embodiments of this application, a fourth aspect of this application also provides an integrated circuit, including a radio frequency module, an analog signal processing module, and a digital signal processing module connected in sequence; the radio frequency module is used to transmit a detection signal in Doppler multiplexing (DDM) mode through multiple transmitting antennas and to receive echo signals through multiple receiving antennas; the analog signal processing module is used to down-convert the echo signals to obtain intermediate frequency (IF) signals; and the digital signal processing module is used to perform analog-to-digital conversion on the IF signals to obtain digital signals, and to perform the following processing on the digital signals: determining a target angle based on the echo signals received through different receiving channels; generating a compensation signal for the transmitted signals of each transmitting channel based on the phase relationship between the target angle and the transmitted signals transmitted through different transmitting channels; and compensating the echo signals received by each receiving channel based on the compensation signal to determine the demodulated signal corresponding to the transmitting channel sequence when the received signal energy of each transmitting channel is at its maximum.

[0019] According to some embodiments of this application, a fifth aspect of this application also provides a wireless device, including: a carrier; an integrated circuit as described above, disposed on the carrier; an antenna, disposed on the carrier, or the antenna and the integrated circuit are integrated into a single device disposed on the carrier; wherein the integrated circuit is connected to the antenna and is used to transmit the detection signal and / or receive the echo signal.

[0020] According to some embodiments of this application, a sixth aspect of this application also provides a terminal device, including: a device body; and a wireless device as described above disposed on the device body; wherein the wireless device is used for target detection to provide reference information to the operation of the device body.

[0021] The technical solution provided in this application embodiment has at least the following advantages: After determining the target angle based on the echo signals received through different receiving channels, compensation signals for the transmitted signals of each transmitting channel are generated based on the phase relationship between the target angle and the transmitted signals transmitted through different transmitting channels. This compensates for the echo signals received by each receiving channel, thereby enabling the demodulation signals corresponding to each transmitting channel to be determined by using the order of the transmitting channels corresponding to the maximum received signal energy as a constraint condition, thus achieving efficient and reliable signal demodulation. Attached Figure Description

[0022] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0023] Figure 1 This is a Doppler spectrum of the echo signal received after DDM modulation according to one embodiment of this application; Figure 2 This is a flowchart of a signal demodulation method provided in another embodiment of this application; Figure 3 This is a schematic diagram of the structure of an electronic device provided in another embodiment of this application; Figure 4 This is a schematic diagram of the integrated circuit provided in another embodiment of this application. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the various embodiments of this application will be described in detail below with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been presented in the various embodiments of this application to enable readers to better understand this application. However, the technical solutions claimed in this application can be implemented even without these technical details and various changes and modifications based on the following embodiments.

[0025] The division of the following embodiments is for ease of description and should not constitute any limitation on the specific implementation of this application. The various embodiments can be combined with and referenced by each other without contradiction.

[0026] Radar measures the spatial parameters of a target, such as range, velocity, and angle, by transmitting and receiving electromagnetic signals. Angle measurement is typically achieved through the signal phase relationship between multiple antenna elements. The more antenna elements, the higher the angle measurement quality. A radar antenna array includes transmitting and receiving antennas. Using MIMO (Multiple-In Multiple-Out) technology, M×N sets of received signals can be obtained by combining M transmitting antennas and N receiving antennas, resulting in M×N equivalent antenna elements, thus improving the angle measurement quality.

[0027] Therefore, a key aspect of signal processing at the receiver is establishing the correspondence between the M×N signal components obtained from the N receiving antennas and the M transmitting antennas, thereby correctly interpreting the signal. This is especially crucial when the transmitting channel is modulated using DDM. Specifically, it involves determining the correspondence between each signal in any set of signal peaks sig[tone, rx] measured by the receiving antennas and each transmitting antenna, where tone represents the tone-th signal in a set and has no specific physical meaning, and rx is the sequence number of the receiving channel.

[0028] For example, when DDM modulation is achieved in four transmission channels with the following phases, the following results are obtained based on a zero-velocity target: Figure 1 The Doppler spectrum of the received echo signal is shown below: Transmit channel TX0: 0deg, 0deg, 0deg, 0deg, ... (at this time the phase step is 0°); Transmit channel TX1: 0deg, 45deg, 90deg, 135deg, ... (the phase step is 45° at this time); Transmit channel TX2: 0deg, 90deg, 180deg, 270deg, ... (the phase step is 90° at this time); Transmit channel TX3: 0deg, 135deg, 270deg, 45deg, ... (the phase step is 135° at this time).

[0029] At this point, since the target velocity is 0, the unmodulated transmitted signal TX0 appears at the zero-frequency position, i.e. Figure 1 The leftmost signal peak is located at the center of the spectrum. The phase steps of the transmitted signals TX1, TX2, and TX3 are 45°, 90°, and 135°, respectively, corresponding to 1 / 8, 2 / 8, and 3 / 8 of the circle. Therefore, the corresponding signals in the Doppler spectrum of TX1, TX2, and TX3 appear at 1 / 8, 2 / 8, and 3 / 8 of the maximum frequency, respectively. The frequency interval between each pair of adjacent transmit channels (TX) is 1 / 8, while there are no peaks formed by target reflection at frequencies of 4 / 8, 5 / 8, 6 / 8, and 7 / 8. At this point, the demodulation of the DDM-modulated transmitted signal at the receiver resolves the correspondence between the eight sets of signals (four of which are actually non-functional signals) and the four transmit antennas.

[0030] However, in reality, on the one hand, the target usually has a certain speed, and the speed is unknown, thus... Figure 1The overall signal will be translated along the horizontal axis based on the target velocity, but the exact amount of translation is uncertain, i.e., the frequency corresponding to the transmission channel TX0 is unknown. On the other hand, due to the non-ideal characteristics of phase modulation, other unwanted signal components may exist at frequencies of 4 / 8 times the target velocity; their intensity is usually lower than the signals corresponding to each transmitting antenna. Figure 1 In addition to the four main signal peaks, there are often four smaller signal peaks located at frequencies of 4 / 8, 5 / 8, 6 / 8, and 7 / 8 times the frequency.

[0031] Therefore, considering the stepping diagram of the transmitted signal provided above, the relative frequency relationships of the transmitted channels TX0, TX1, TX2, and TX3 are known from the modulation sequence. Thus, the commonly used DDM demodulation algorithm is as follows: for a set of 8 signal peaks, construct 8 4-signal combinations according to the known frequency relationships, and take the set with the largest sum as the demodulated signal of each transmitted channel TX.

[0032] However, the above method involves overly complex and cumbersome calculations for constructing signal combinations each time, resulting in low demodulation efficiency and unreliable results.

[0033] Based on this, the first aspect of this application provides a signal demodulation method applied to the receiving end of a radar device (equipment or device, etc.), offering a different signal demodulation scheme from existing DDM methods, making demodulation more efficient and accurate. The following will combine... Figure 2 The flowchart shown illustrates the signal demodulation method provided in the embodiments of this application.

[0034] like Figure 2 As shown, the signal demodulation method includes at least the following steps: Step 101: Determine the target angle based on the echo signals received through different receiving channels.

[0035] Step 102: Generate compensation signals for the transmission signals of each transmission channel based on the phase relationship between the target angle and the transmission signals transmitted through different transmission channels.

[0036] Step 103: Based on the compensation signal, compensate the echo signals received by each receiving channel to determine the demodulation signal corresponding to the transmission channel sequence when the received signal energy is at its maximum.

[0037] For ease of understanding Figure 2 The steps of the illustrated embodiment will be described below.

[0038] In step 101, the target angle is determined based on the echo signals received through different receiving channels. This application does not limit the calculation method of the target angle. It is understood that although signals may have uncertain correspondences within the same transmission channel, the effect of the target angle is the same across different transmission channels. Therefore, the target angle can be obtained from the echo signals received through different receiving channels. Such schemes have been described in relevant radar demodulation or channel separation technologies and will not be listed here.

[0039] In step 102, compensation signals for the transmitted signals of each transmission channel are generated based on the target angle and the phase relationship between the transmitted signals transmitted through different transmission channels. This embodiment does not limit the phase relationship between the transmitted signals transmitted through different transmission channels; it can be any phase relationship that satisfies the phase modulation of the transmitted signals from different transmission channels based on Doppler multiplexing.

[0040] In some embodiments, phase modulation of the transmitted signals from different transmission channels based on Doppler multiplexing includes linearly stepped phase changes of the transmitted signals from different transmission channels. That is, different transmission channels employ a basic DDM modulation method; for example, the signals transmitted by different transmission channels might be as follows: Transmit channel TX0: 0deg, 0deg, 0deg, 0deg, ... (at this time the phase step is 0°); Transmit channel TX1: 0deg, 45deg, 90deg, 135deg, ... (the phase step is 45° at this time); Transmit channel TX2: 0deg, 90deg, 180deg, 270deg, ... (the phase step is 90° at this time); Transmit channel TX3: 0deg, 135deg, 270deg, 45deg, ... (the phase step is 135° at this time).

[0041] In some embodiments, the phases of the signals transmitted through different transmission channels are modulated at 0° or 180°, and the periods of the phase modulation sequences are unequal and factorial to each other; the period sequences of the phase modulation sequences of any two transmission channels are orthogonal. That is, different transmission channels employ BPDDM modulation. For example, the sequences corresponding to the signals transmitted through different transmission channels are as follows: Transmit channel TX0: ++++++++++++; Transmit channel TX1: + - + - + - + -; Transmit channel TX2: - + + - - + + -; Transmission channel TX3: + + + + - - - -.

[0042] Of course, the above is just an example and does not mean that only 4 transmission channels can be used, or that the transmission channels can only be phase-stepped or inverted according to the above example. In practice, they can be set according to the requirements, which will not be listed here.

[0043] Based on the above description of the transmitted signals of different transmission channels, it is not difficult to see that the phase relationship between the transmitted signals of different transmission channels is actually known during demodulation, and each can be represented as superimposing the corresponding phase modulation processing on the transmitted signal of one of the transmission channels. Therefore, in some embodiments, the transmission signal compensation signal of each transmission channel is generated according to the phase relationship between the target angle and the transmitted signals transmitted by different transmission channels. This can be achieved in the following way: Based on the phase relationship between the target angle and the transmitted signals transmitted by different transmission channels, a compensation signal for each transmission channel is generated based on the transmitted signal of the target transmission channel.

[0044] In some embodiments, the target transmission channel can be a transmission channel whose transmitted signal is not modulated, such as the aforementioned transmission channel TX0. Therefore, the phase relationship between different transmission channels relative to the target transmission channel will be more concise, easier to process, and reduce computational load.

[0045] Of course, in some embodiments, the target transmission channel may also use other transmission channels, which will not be listed here.

[0046] Taking a target transmission channel that can be an unmodulated transmission channel as an example, in some embodiments, compensation signals for each transmission channel based on the target transmission channel's transmission signal are generated according to the phase relationship between the target angle and the transmission signals emitted by different transmission channels. This can be achieved as follows: Based on the phase offset to be compensated for by each transmission channel determined by the phase relationship between the target angle and the transmission signals emitted by different transmission channels, compensation signals for each transmission channel based on the target transmission channel's transmission signal are generated. Thus, the phase offset to be compensated for by each transmission channel is directly determined through the phase relationship between the transmission signals emitted by different transmission channels, and then combined with the target angle, the amount to be compensated is determined. This method is efficient and provides accurate and reliable compensation results.

[0047] In some examples, the phase offset that each transmission channel needs to compensate for, determined based on the target angle and the phase relationship between the transmitted signals transmitted from different transmission channels, is used to generate a compensation signal for each transmission channel based on the transmitted signal from the target transmission channel. This can be achieved through the following expression: comp[tx]=e^[-j×φ(tx+tone_{candidate}, θ)]; Where comp[tx] is the compensation signal corresponding to the transmission channel with serial number tx, tone_{candidate} is the transmission channel offset determined according to the phase relationship between the transmission signals transmitted by different transmission channels, for example, it can be the offset of the transmission channel with serial number tx relative to the target transmission channel determined according to the phase relationship between the transmission signals transmitted by different transmission channels, and θ is the target angle.

[0048] In step 103, the echo signals received by each receiving channel are compensated according to the compensation signal to determine the demodulated signal corresponding to the transmission channel sequence when the received signal energy is at its maximum. In this embodiment, the compensation signal is directly constructed. Although the maximum received signal energy is still the constraint, compared to the current convenient combination of various signals, the compensation signal is directly determined, and the processing required during demodulation is changed to filtering, which is simpler, less difficult, and more efficient. Moreover, the compensation signal is obtained through the phase relationship between the transmitted signals of different transmission channels, making the demodulated signal less susceptible to noise interference and more reliable.

[0049] Taking phase-stepped DDM modulation as an example, the transmitted signal can be represented as follows: Signal[TX,t,T] = Signal[LO,t]×[e^(j×Δφ[TX]×T)]; Where Signal[TX, t, T] is the transmitted signal of the transmission channel with sequence number TX, Δφ[TX] is the phase step of the transmission channel with sequence number TX, T is the pulse sequence number, and t is the time.

[0050] As shown above, the modulation phase of the transmitted signal from the transmission channel with serial number TX changes linearly with the number of pulses T. Furthermore, due to the different phase steps of different transmission channels, the echo signals obtained by different transmitting antennas for the same target in the received signal have a specific inter-pulse Doppler frequency relationship. Once the signal corresponding to a transmission channel is determined, the transmission channels corresponding to each signal will be determined accordingly.

[0051] Based on this, in some embodiments, the echo signals received by each receiving channel are compensated according to the compensation signal to determine the demodulated signal corresponding to the transmission channel sequence when the received signal energy is at its maximum. This can be achieved as follows: the echo signals received by each receiving channel are compensated according to the compensation signal corresponding to the target transmission channel to determine the demodulated signal corresponding to the target transmission channel when the received signal energy is at its maximum; the demodulated signals corresponding to other transmission channels besides the target transmission channel are determined according to the phase relationship between the demodulated signal corresponding to the target transmission channel and the transmission signals transmitted by different transmission channels.

[0052] In some embodiments, taking the target transmitting channel as an example where the transmitted signal is not modulated, the echo signals received by each receiving channel are compensated according to the compensation signal to determine the demodulated signal corresponding to the transmitting channel sequence when the received signal energy is at its maximum. This can be achieved by performing Fast Fourier Transform, multiplication, and Inverse Fast Fourier Transform on the compensation signal and the echo signals received by each receiving channel in the transmitting channel dimension to generate the demodulated signal corresponding to the transmitting channel sequence when the received signal energy is at its maximum.

[0053] In some examples, the demodulated signal corresponding to each transmit channel can be obtained by the following expression: convolution(comp[tx], sig[tx, rx]) = ifft(fft_{tx}(comp[tx])×fft_{tx}(sig[tx, rx])); Where convolution(comp[tx], sig[tx, rx]) is the demodulated signal corresponding to the transmit channel with sequence number tx in the receive channel with sequence number rx, comp[tx] is the compensation signal corresponding to the transmit channel with sequence number tx, sig[tx, rx] is the signal part of the echo signal received by the receive channel with sequence number rx, which is affected by the signal transmitted by the transmit channel with sequence number tx. ifft(fft_{tx}(comp[tx])×f `ft_{tx}(sig[tx, rx])` performs an inverse Fast Fourier Transform on the result of `fft_{tx}(comp[tx]) × fft_{tx}(sig[tx, rx])`, `fft_{tx}(comp[tx])` performs a Fast Fourier Transform on the `comp[tx]` signal in the transmit channel dimension, and `fft_{tx}(sig[tx, rx])` performs a Fast Fourier Transform on the `sig[tx, rx]` signal in the transmit channel dimension.

[0054] To facilitate understanding of the above embodiments and their effects by those skilled in the art, the following will explain them from a principle perspective.

[0055] First, the echo signal can be modeled as follows: sig[tx, rx] = e^{j×[(φ (tx, θ) + Ψ(rx, θ)]} (1); Where sig[tx, rx] represents the signal that should be generated when the transmitted signal from the transmitting channel with sequence number tx acts on the receiving channel with sequence number rx, φ(tx, θ) is the phase generated based on the target angle and the action of the transmitting channel with sequence number tx, and Ψ(rx, θ) is the phase generated based on the target angle and the action of the receiving channel with sequence number rx.

[0056] Compared to the measured signal sig[tone, rx], the target angle θ and the transmission channel number tx in equation (1) can be regarded as unknowns. That is, for a specific tone coordinate, sig[tone=0, 1, ..., rx], the tone coordinate (i.e. tone0, the initial value of the frequency offset corresponding to the target transmission channel) of the transmission channel tx0 (target transmission channel, or, the transmission channel with the transmission signal not modulated) in the corresponding signal sig[tx, rx] is unknown, and the target angle is also unknown.

[0057] However, it is known that the above parameters satisfy: tx = tone – tone0. Therefore, for any given tone, tx degenerates into a definite but unknown constant {tx_unknown}, where {tx_unknown} satisfies the following expression: sig[tone, rx] = e^[j×φ(tx_{unknown}, θ) + j×Ψ(rx, θ)] (2); Since tx_{unknown} is a constant, the phase difference of the echo signal between different receiving channels in equation (2) is determined only by the known quantity rx and the unknown quantity θ. Therefore, θ is estimated based on the echo signal between different receiving channels.

[0058] At this point, since θ is known and rx is also determined, for any specific rx signal, the term Ψ(rx, θ) related to rx degenerates into a definite value. When focusing on solving the transmission channel separation problem later, the signal part containing rx can be regarded as a known quantity. During the analysis, the influence of Ψ(rx, θ) on sig[tone, rx] can be temporarily ignored.

[0059] Therefore, after setting tx = tone – tone0 in equation (1), we will get: sig[tx, rx] = e^{j×[φ(tx+tone0, θ) + Ψ(rx, θ)]}(3); In other words, the phase relationship between signals of different tones is determined only by the known quantity θ and the unknown quantity tone0. Thus, given the tone signal and θ, tone0 can be estimated, that is, the position corresponding to tone0 can be determined.

[0060] Specifically, for different tone_{candidate} to be tested (where tone0 is a known unknown constant and tone_{candidate} is the variable to be tested), the compensation signal for each tone signal can be clearly identified: comp[tx]=e^[-j×φ(tx+tone_{candidate}, θ)](4); Therefore, compensation is calculated based on the above compensation signal: sum_{tx} {e^[j×φ(tx+tone0, θ) + j×Ψ(rx, θ)] – j×φ(tx+tone_{candidate}, θ)]} (5); Where sum_{tx}{e^[j×φ(tx+tone0,θ)+ j ×Ψ(rx,θ)] – j×φ(tx+tone_{candidate},θ)]} represents summing the signal e^[j×φ (tx+tone0,θ) + j×Ψ(rx,θ)] – j×φ(tx+tone_{candidate},θ)] across different dimensions of tx.

[0061] For equation (5), when the variable tone_{candidate} is equal to tone0, it will be simplified to: sum_{tx}{e^[j×Ψ(rx, θ)]}(6); Equation (6) can be further expressed as: sum_{tx}{e^[j×Ψ(rx, θ)]}=TX×e^[j×Ψ(rx, θ)]] (7); Where TX represents the total number of items with serial number tx.

[0062] For equation (7), find the position corresponding to tone0 when its amplitude reaches its maximum value, which is used as the estimate of tone0. Thus, other tones can be determined based on the phase relationship between the transmitted signals of different transmission channels, thereby realizing DDM demodulation.

[0063] In equation (5), when tone_{candidate} iterates through all possible values, the compensation signal comp[tx] = e^[-j×φ(tx+tone_{candidate}, θ)] actually describes a cyclic translation. Therefore, demodulation via equation (5) is equivalent to calculating the convolution of sig[tone, rx] and the compensation signal comp[tx], i.e., convolution(comp[tx], sig[tx, rx]). A simplified algorithm exists for convolution calculation: convolution(comp[tx], sig[tx, rx]) = ifft(fft_{tx}(comp[tx])×fft_{tx}(sig[tx, rx])) (8); Where convolution(comp[tx], sig[tx, rx]) is the demodulated signal corresponding to the transmitting channel with sequence number tx in the receiving channel with sequence number rx, comp[tx] is the compensation signal corresponding to the transmitting channel with sequence number tx, sig[tx, rx] is the signal portion of the echo signal received by the receiving channel with sequence number rx, which is affected by the signal transmitted by the transmitting channel with sequence number tx, and ifft(fft_{tx}(comp[tx])× `fft_{tx}(sig[tx, rx])` performs an inverse Fast Fourier Transform on the result of `fft_{tx}(comp[tx]) × fft_{tx}(sig[tx, rx])`, `fft_{tx}(comp[tx])` performs a Fast Fourier Transform on the `comp[tx]` signal in the transmit channel dimension, and `fft_{tx}(sig[tx, rx])` performs a Fast Fourier Transform on the `sig[tx, rx]` signal in the transmit channel dimension.

[0064] For a given DDM modulation scheme, fft_{tx}(comp[tx]) is fixed. Therefore, it can be pre-stored and reused each time demodulation is performed. Thus, the actual operations required during demodulation are to perform the FFT operation of fft_{tx}(sig[tx, rx]) and the IFFT operation of ifft(fft_{tx}(comp[tx])×fft_{tx}(sig[tx, rx])). Obviously, compared with the existing scheme, the calculation is simpler and more efficient. Especially when there are various efficient FFT and IFFT algorithms, the demodulation is more efficient and reliable.

[0065] The steps of the various methods described above are only for clarity. In practice, they can be combined into one step or some steps can be split into multiple steps. As long as they include the same logical relationship, they are all within the scope of protection of this patent. Adding insignificant modifications or introducing insignificant designs to the algorithm or process, but without changing the core design of the algorithm and process, are also within the scope of protection of this patent.

[0066] Correspondingly, embodiments of this application also provide a radar chip, such as... Figure 3 As shown, it includes: at least one processor 301; and a memory 302 communicatively connected to at least one processor 301; wherein the memory 302 stores instructions executable by at least one processor 301, the instructions being executed by at least one processor 301 to enable at least one processor 301 to perform the signal demodulation method described in any of the above method embodiments.

[0067] The memory 302 and processor 301 are connected via a bus, which can include any number of interconnecting buses and bridges. The bus connects various circuits of one or more processors 301 and memory 302 together. The bus can also connect various other circuits, such as peripheral devices, voltage regulators, and power management circuits, which are well known in the art and therefore will not be described further herein. A bus interface provides an interface between the bus and the transceiver. The transceiver can be a single element or multiple elements, such as multiple receivers and transmitters, providing a unit for communicating with various other devices over a transmission medium. Data processed by processor 301 is transmitted over a wireless medium via an antenna, which further receives data and transmits it to processor 301.

[0068] Processor 301 is responsible for managing the bus and general processing, and can also provide various functions, including timing, peripheral interfaces, voltage regulation, power management, and other control functions. Memory 302 can be used to store data used by processor 301 during operation.

[0069] This application also provides a computer-readable storage medium storing a computer program. When executed by a processor, the computer program implements the signal demodulation method provided in any of the above-described method embodiments.

[0070] Those skilled in the art will understand that all or part of the steps in the methods of the above embodiments can be implemented by a program instructing related hardware. This program is stored in a storage medium and includes several instructions to cause a device (which may be a microcontroller, chip, etc.) or processor to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as a USB flash drive, a portable hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0071] The technical solution according to the embodiments of this application can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (such as a CD-ROM, USB flash drive, mobile hard drive, etc.) or on a network, and includes several instructions to cause a computing device (such as a personal computer, server, or network device, etc.) to execute the above-described method according to the embodiments of this application.

[0072] Software products may employ any combination of one or more readable media. A readable medium may be a readable signal medium or a readable storage medium. A readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of readable storage media (a non-exhaustive list) include: electrical connections with one or more wires, portable disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0073] Computer-readable storage media may include data signals propagated in baseband or as part of a carrier wave, carrying readable program code. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A readable storage medium may also be any readable medium other than a readable storage medium that can transmit, propagate, or transfer a program for use by or in connection with an instruction execution system, apparatus, or device. The program code contained on the readable storage medium may be transmitted using any suitable medium, including but not limited to wireless, wired, optical fiber, RF, etc., or any suitable combination thereof.

[0074] Program code for performing the operations of this application can be written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Java and C++, and conventional procedural programming languages ​​such as C or similar languages. The program code can execute entirely on the user's computing device, partially on the user's computing device, as a standalone software package, partially on the user's computing device and partially on a remote computing device, or entirely on a remote computing device or server. In cases involving remote computing devices, the remote computing device can be connected to the user's computing device via any type of network, including a local area network (LAN) or a wide area network (WAN), or it can be connected to an external computing device (e.g., via the Internet using an Internet service provider).

[0075] The aforementioned computer-readable medium carries one or more programs, which, when executed by a device, enable the computer-readable medium to perform the aforementioned functions.

[0076] This invention also provides an integrated circuit, such as... Figure 4 As shown, the system includes a radio frequency (RF) module 401, an analog signal processing module 402, and a digital signal processing module 403 connected in sequence. The RF module 401 transmits probe signals via multiple transmitting antennas in Doppler multiplexing (DDM) mode and receives echo signals via multiple receiving antennas. The analog signal processing module 402 down-converts the echo signals to obtain intermediate frequency (IF) signals. The digital signal processing module 403 performs analog-to-digital conversion on the IF signals to obtain digital signals, and then processes the digital signals as follows: determining the target angle based on the echo signals received through different receiving channels; generating compensation signals for the transmitted signals of each transmitting channel based on the phase relationship between the target angle and the transmitted signals from different transmitting channels; and compensating the echo signals received by each receiving channel based on the compensation signals to determine the demodulated signals corresponding to the transmitting channel sequence when the received signal energy is at its maximum.

[0077] It is not difficult to see that this embodiment is a circuit embodiment corresponding to the method embodiment, and this embodiment can be implemented in conjunction with the method embodiment. The relevant technical details mentioned in the method embodiment are still valid in this embodiment, and will not be repeated here to reduce repetition. Correspondingly, the relevant technical details mentioned in this embodiment can also be applied to the method embodiment.

[0078] Furthermore, in order to highlight the innovative aspects of this application, no units that are not closely related to solving the technical problems proposed in this application are introduced in this embodiment, but this does not mean that there are no other units in this embodiment.

[0079] This application also provides a wireless device, comprising: a carrier, the aforementioned integrated circuit disposed on the carrier, and an antenna disposed on the carrier, or the antenna and integrated circuit integrated into a single device disposed on the carrier. The integrated circuit is connected to the antenna and is used to transmit target detection signals and / or receive echo signals.

[0080] When the antenna and integrated circuit are not integrated into a single device, the integrated circuit is connected to the antenna via a first transmission line, which can be a PCB trace. The carrier can be a printed circuit board (PCB), such as a development board, data acquisition board, or the motherboard of a device, etc., which will not be elaborated on here.

[0081] Since the structure and working principle of the integrated circuits included in the wireless devices have been described in detail in the above embodiments, they will not be repeated here.

[0082] This application also provides a terminal device, including: a device body; and a wireless device as described above disposed on the device body; wherein the wireless device is used for target detection to provide reference information to the operation of the device body.

[0083] In one embodiment of this application, the wireless device may be disposed outside the device body. In another embodiment, the wireless device may be disposed inside the device body. In still other embodiments, the wireless device may be partially disposed inside the device body and partially disposed outside the device body. This application does not limit the specific implementation; the choice depends on the circumstances.

[0084] It should be noted that wireless devices can achieve functions such as target detection by transmitting and receiving radio signals, thereby providing the device body with measurement information of the detected target, and thus assisting or even controlling the operation of the device body. Examples of such measurement information include at least one of relative distance, relative speed, and relative angle.

[0085] In an optional embodiment, the aforementioned device body can be a component or product applied in fields such as transportation, consumer electronics, monitoring, in-cabin detection, and healthcare. For example, the device body can be intelligent transportation equipment (such as automobiles, motorcycles, ships, subways, trains, etc.), security equipment (such as cameras), liquid level / flow rate detection equipment, smart wearable devices (such as wristbands, glasses, etc.), smart home devices (such as robot vacuum cleaners, door locks, televisions, air conditioners, smart lights, etc.), various communication devices (such as mobile phones, tablets, etc.), as well as devices such as barriers, intelligent traffic lights, intelligent signs, traffic cameras, and various industrial robotic arms (or robots). It can also be various instruments used to detect vital signs parameters and various devices equipped with such instruments, such as in-cabin detection in automobiles, indoor personnel monitoring, intelligent medical devices, and consumer electronic devices.

[0086] In another alternative embodiment, when the aforementioned device body is applied to an advanced driver assistance system (i.e., ADAS), the wireless device, as an on-board sensor, can provide various functional safety guarantees for the ADAS system, such as automatic brake assist (i.e., AEB), blind spot detection warning (i.e., BSD), lane change assist warning (i.e., LCA), and reversing assist warning (i.e., RCTA).

[0087] Furthermore, the examples mentioned in the above embodiments can be freely combined, and any combination can be understood as an embodiment. The terms "embodiment" or "example" appearing in various locations in the specification do not necessarily refer to the same embodiment, nor are they independent or alternative embodiments mutually exclusive with other embodiments. Those skilled in the art will understand that the embodiments described herein can be combined with other embodiments.

[0088] Those skilled in the art will understand that the above embodiments are specific embodiments for implementing this application, and in practical applications, various changes can be made to them in form and detail without departing from the spirit and scope of this application.

[0089] Those skilled in the art will understand that the above embodiments are specific embodiments for implementing this application, and in practical applications, various changes can be made to them in form and detail without departing from the spirit and scope of this application.

Claims

1. A signal demodulation method, characterized in that, include: The target angle is determined based on the echo signals received through different receiving channels; Based on the target angle and the phase relationship between the transmitted signals emitted by different transmission channels, a compensation signal for the transmitted signal of each transmission channel is generated; Based on the compensation signal, the echo signals received by each receiving channel are compensated to determine the demodulated signal corresponding to the transmission channel sequence when the received signal energy of each transmitting channel is at its maximum.

2. The signal demodulation method according to claim 1, characterized in that, The step of generating a transmission signal compensation signal for each transmission channel based on the target angle and the phase relationship between the transmission signals transmitted through different transmission channels includes: Based on the phase relationship between the target angle and the transmission signals transmitted through different transmission channels, a compensation signal is generated for each transmission channel, representing the transmission signal of the target transmission channel.

3. The signal demodulation method according to claim 2, characterized in that, The step of compensating the echo signals received by each receiving channel according to the compensation signal to determine the demodulated signal corresponding to the transmission channel sequence when the received signal energy of each transmitting channel is at its maximum includes: Based on the compensation signal corresponding to the target transmission channel, the echo signal received by each receiving channel is compensated to determine the demodulated signal corresponding to the target transmission channel under the transmission channel sequence when the received signal energy is at its maximum. Based on the phase relationship between the demodulated signal corresponding to the target transmission channel and the transmission signals transmitted by different transmission channels, the demodulated signals corresponding to other transmission channels besides the target transmission channel are determined.

4. The signal demodulation method according to claim 3, characterized in that, The target transmission channel is a transmission channel in which the transmitted signal is not modulated.

5. The signal demodulation method according to claim 4, characterized in that, The step of generating the compensation signal for each transmission channel based on the target transmission channel's transmission signal, according to the phase relationship between the target angle and the transmission signals transmitted through different transmission channels, includes: Based on the phase relationship between the target angle and the phase offset of each transmission channel that needs to be compensated, the compensation signal of each transmission channel is generated based on the transmission signal of the target transmission channel.

6. The signal demodulation method according to claim 5, characterized in that, The phase offset that needs to be compensated for by each transmission channel, determined based on the target angle and the phase relationship between the transmitted signals transmitted from different transmission channels, is used to generate the compensation signal for each transmission channel based on the transmitted signal of the target transmission channel. This is achieved through the following expression: comp[tx]=e^[-j×φ(tx+tone_{candidate}, θ)]; Where comp[tx] is the compensation signal corresponding to the transmission channel with serial number tx, tone_{candidate} is the transmission channel offset determined according to the phase relationship between the transmission signals transmitted by different transmission channels, and θ is the target angle.

7. The signal demodulation method according to claim 4, characterized in that, The step of compensating the echo signals received by each receiving channel according to the compensation signal to determine the demodulated signal corresponding to the transmission channel sequence when the received signal energy of each transmitting channel is at its maximum includes: The compensation signal and the echo signal received by each receiving channel are subjected to Fast Fourier Transform, multiplication and inverse Fast Fourier Transform in the dimension of the transmitting channel to generate the demodulated signal corresponding to the transmitting channel sequence when the received signal energy of each transmitting channel is at its maximum.

8. The signal demodulation method according to claim 7, characterized in that, The fast Fourier transform, multiplication, and inverse fast Fourier transform of the compensation signal and the echo signals received by each receiving channel are performed along the transmission channel dimension, which is achieved by the following expression: convolution(comp[tx], sig[tx, rx]) = ifft(fft_{tx}(comp[tx])×fft_{tx}(sig[tx, rx])); Where convolution(comp[tx], sig[tx, rx]) represents the demodulated signal corresponding to the transmit channel with sequence number tx in the receive channel with sequence number rx, and comp[tx] represents the demodulated signal. Let be the compensation signal corresponding to the transmitting channel with sequence number tx, and sig[tx, rx] be the signal portion of the echo signal received by the receiving channel with sequence number rx, which is affected by the signal transmitted by the transmitting channel with sequence number tx. ifft(fft_{tx}(comp[tx])×fft_{tx}(sig[tx, rx])) is the result of fft_{tx}(comp[tx])×fft_{tx}(sig[tx, rx]), fft_{tx}(comp[tx]) is the result of fft_{tx}(comp[tx])×fft_{tx}(sig[tx, rx]), fft_{tx}(comp[tx]) is the result of fft_{tx}(comp[tx])×fft_{tx}(sig[tx, rx]), fft_{tx}(comp[tx]) is the result of fft_{tx}(comp[tx])×fft_{tx}(sig[tx, rx]), and fft_{tx}(sig[tx, rx]) is the result of fft_{tx, rx]×fft_{tx}(sig[tx, rx]).

9. The signal demodulation method according to any one of claims 1 to 8, characterized in that, The transmitted signals from the different transmission channels are phase-modulated based on Doppler multiplexing.

10. The signal demodulation method according to claim 9, characterized in that, The phase of the transmitted signals from the different transmission channels changes linearly.

11. The signal demodulation method according to claim 9, characterized in that, The phase of the transmitted signals from the different transmission channels is modulated at 0° or 180°, and the periods of the phase modulation sequences are not equal and are factor-dependent on each other. The period sequences of the phase modulation sequences of any two transmission channels are orthogonal.

12. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by a processor, it implements the signal demodulation method as described in any one of claims 1 to 11.

13. A radar chip, characterized in that, include: At least one processor; as well as, A memory communicatively connected to the at least one processor; wherein, The memory stores instructions that can be executed by the at least one processor to enable the at least one processor to perform the signal demodulation method as described in any one of claims 1 to 11.

14. An integrated circuit, characterized in that, It includes a radio frequency module, an analog signal processing module, and a digital signal processing module connected in sequence; The radio frequency module is used to transmit detection signals in Doppler multiplexing (DDM) mode through multiple transmitting antennas and to receive echo signals through multiple receiving antennas. The analog signal processing module is used to down-frequency the echo signal to obtain an intermediate frequency signal; and The digital signal processing module is used to perform analog-to-digital conversion on the intermediate frequency signal to obtain a digital signal, and to perform the following processing on the digital signal: The target angle is determined based on the echo signals received through different receiving channels; Based on the target angle and the phase relationship between the transmitted signals emitted by different transmission channels, a compensation signal for the transmitted signal of each transmission channel is generated; Based on the compensation signal, the echo signals received by each receiving channel are compensated to determine the demodulated signal corresponding to the transmission channel sequence when the received signal energy of each transmitting channel is at its maximum.

15. A wireless device, characterized in that, include: Carrier; The integrated circuit as described in claim 14 is disposed on the carrier; An antenna is disposed on the carrier, or the antenna and the integrated circuit are integrated into a single device and disposed on the carrier. The integrated circuit is connected to the antenna and is used to transmit the detection signal and / or receive the echo signal.

16. A terminal device, characterized in that, include: Equipment body; as well as The wireless device as described in claim 15 is disposed on the device body; The wireless device is used for target detection to provide reference information for the operation of the device body.

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