A frequency diversity method and system for sharing analog transceiver channels

Abstract

The application discloses a frequency diversity method and system of a shared analog receiving and transmitting channel, and the method comprises the following steps: continuously time-divisionally transmitting a plurality of different frequency signals; mixing different frequency target echoes with a first local oscillator signal to obtain a first intermediate frequency signal, mixing the first intermediate frequency signal with a second local oscillator signal through the same analog receiving channel to obtain a second intermediate frequency signal; performing A / D conversion on the second intermediate frequency signal to obtain a digital signal; performing digital down conversion on the digital signal to obtain a digital down conversion output signal; and obtaining radar echoes of different diversity frequencies based on the digital down conversion output signal. The application realizes frequency diversity of a radar by sharing the same receiving and transmitting analog channel, and realizes receiving echo processing of a plurality of diversity frequencies by using a digital multi-channel processing method, thereby saving hardware cost and reducing system complexity.

Description

Technical Field

[0001] This invention relates to the field of radar signal processing technology, and specifically to a frequency diversity method and system for sharing an analog transceiver channel. Background Technology

[0002] Frequency diversity is a radar anti-jamming technology that refers to the simultaneous transmission of two or more radio frequency signals at different frequencies by the radar, with the echoes processed through their respective receiving channels. The echo signals from multiple channels accumulate to form diversity gain. Although diversity radar has excellent target echo stability, the multiple channels increase the hardware cost of the radar. While single-channel radar has relatively low hardware cost, it also has drawbacks. It is difficult to completely separate multiple echo signals in a single analog channel using only a mixer. If multiple signals cannot be separated, deviations and errors will occur in subsequent signal processing, such as pulse compression, which will seriously affect signal processing. Summary of the Invention

[0003] To overcome the defects and shortcomings of existing technologies, this invention provides a frequency diversity method and system with a shared analog transceiver channel. During transmission, this invention continuously transmits two or more different frequency signals in a time-division manner. During reception, the radar echo is A / D converted and then processed into multiple digital DC channels, enabling the radar to share the same analog transceiver channel to achieve frequency diversity. The digital multi-channel processing method is used to process the received echoes of multiple diversity frequencies, saving hardware costs and reducing system complexity.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] This invention provides a frequency diversity method for a shared analog transceiver channel, comprising the following steps:

[0006] Continuously transmit multiple signals of different frequencies in a time-division manner;

[0007] The first intermediate frequency signal is obtained by mixing the target echoes of different frequencies with the first local oscillator signal. The first intermediate frequency signal is then mixed with the second local oscillator signal through the same analog receiving channel to obtain the second intermediate frequency signal.

[0008] The second intermediate frequency signal is converted into a digital signal through an A / D converter;

[0009] A digital down-conversion is performed on a digital signal to obtain a digital down-converted output signal;

[0010] Radar echoes at different diversity frequencies are obtained based on the digital down-conversion output signal.

[0011] As a preferred technical solution, the continuous time-division transmission of multiple signals of different frequencies uses two linear frequency modulated signals of different frequencies.

[0012] As a preferred technical solution, the frequencies of the linear frequency modulated signal are set to f1±B / 2 and f2±B / 2, where B is the signal bandwidth, and f1 and f2 are the center frequencies of two different frequency signals.

[0013] As a preferred technical solution, the intermediate frequency of the second intermediate frequency signal is:

[0014]

[0015] Wherein, IF represents the intermediate frequency of the second intermediate frequency signal, B is the signal bandwidth, and f1 and f2 are the center frequencies of the two signals with different frequencies, respectively.

[0016] As a preferred technical solution, the digital signal is digitally down-converted to obtain a digitally down-converted output signal. The center frequencies of the digitally down-converted output signal are as follows:

[0017] and

[0018] Wherein, IF represents the intermediate frequency of the second intermediate frequency signal, and f1 and f2 are the center frequencies of the two signals with different frequencies.

[0019] This invention provides a frequency diversity system with a shared analog transceiver channel, comprising: a signal transmitting unit, a receiver, a mixing unit, an A / D conversion unit, a digital down-conversion unit, and an echo processing unit;

[0020] The signal transmitting unit is used to continuously transmit multiple signals of different frequencies in a time-division manner.

[0021] The receiver is used to receive target echoes of different frequencies;

[0022] The mixing unit is used to mix target echoes of different frequencies with the first local oscillator signal to obtain a first intermediate frequency signal, and to mix the first intermediate frequency signal with the second local oscillator signal through the same analog receiving channel to obtain a second intermediate frequency signal.

[0023] The A / D conversion unit is used to convert the second intermediate frequency signal into a digital signal through A / D conversion;

[0024] The digital downconversion unit is used to perform digital downconversion on the digital signal to obtain a digital downconverted output signal.

[0025] The echo processing unit is used to obtain radar echoes of different diversity frequencies based on the digital down-conversion output signal.

[0026] As a preferred technical solution, the signal transmitting unit is used to continuously transmit multiple signals of different frequencies in a time-division manner, and the frequency signals adopt two linear frequency modulated signals of different frequencies.

[0027] As a preferred technical solution, the frequencies of the linear frequency modulated signal are set to f1±B / 2 and f2±B / 2, where B is the signal bandwidth, and f1 and f2 are the center frequencies of two different frequency signals.

[0028] As a preferred technical solution, the intermediate frequency of the second intermediate frequency signal is:

[0029]

[0030] Wherein, IF represents the intermediate frequency of the second intermediate frequency signal, B is the signal bandwidth, and f1 and f2 are the center frequencies of the two signals with different frequencies, respectively.

[0031] As a preferred technical solution, the digital down-conversion unit is used to perform digital down-conversion on the digital signal to obtain a digital down-converted output signal, wherein the center frequencies of the digital down-converted output signal are as follows:

[0032] and

[0033] Wherein, IF represents the intermediate frequency of the second intermediate frequency signal, and f1 and f2 are the center frequencies of the two signals with different frequencies.

[0034] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0035] In existing technologies, the first intermediate frequency (IF) signal obtained from the first mixing in the receiver is filtered in two paths, and the two signals are then converted to the second IF through two analog channels. This requires multiple analog channels for transmission and reception, resulting in complex hardware design and high costs. This invention continuously transmits two or more different frequency signals in a time-division manner during transmission, and performs multi-channel digital digital conversion (DDC) on the radar echo after A / D conversion during reception. This allows the radar to share the same analog transmission and reception channel to achieve frequency diversity. The digital multi-channel processing method realizes the reception echo processing of multiple diversity frequencies, saving hardware costs, reducing system complexity, and can be extended to other frequency-agile radar designs, making it highly adaptable. Attached Figure Description

[0036] Figure 1 This is a flowchart illustrating the frequency diversity method for the shared analog transceiver channel of the present invention.

[0037] Figure 2 This is a schematic diagram of the frequency diversity radar transmission timing of the present invention;

[0038] Figure 3 This is a schematic diagram of the frequency diversity radar target echo reception and processing process in the traditional method.

[0039] Figure 4This is a schematic diagram of the intermediate frequency (IF) of the dual analog channels in the traditional method;

[0040] Figure 5 This is a schematic diagram of the frequency diversity radar target echo reception and processing flow of the present invention;

[0041] Figure 6 This is a schematic diagram of the intermediate frequency of a single analog channel according to the present invention. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0043] Example 1

[0044] like Figure 1 As shown, this embodiment provides a frequency diversity method for a shared analog transceiver channel, including the following steps:

[0045] S1: Continuously transmit different diversity frequencies in a time-division manner, and can continuously transmit two or more different frequency signals in a time-division manner;

[0046] This embodiment uses two linear frequency modulated signals of different frequencies as an example for illustration, such as... Figure 2 As shown, the frequencies are set to f1±B / 2 and f2±B / 2, where B is the signal bandwidth. The diagonal line in the figure indicates that the signal is a positive slope frequency-modulated wave. f1 and f2 are the center frequencies of two different frequency signals. Since the two different frequency signals are transmitted continuously in a time-division manner, they can share a single transmission channel to achieve transmission at different diversity frequencies. That is, the transmission channel can be time-division multiplexed. The target echoes within their transmission period arrive at the receiver simultaneously, so they can only be separated from each other in the frequency domain.

[0047] S2: Echoes from targets at different frequencies pass through the same analog receiving channel at the intermediate frequency:

[0048]

[0049] Where, assuming f2 > f1, IF represents the intermediate frequency of the signal;

[0050] S3: The intermediate frequency signal is converted into a digital signal via an A / D converter;

[0051] S4: Performs two-channel digital down-conversion (DDC) on the digital signal. The center frequencies of the two DDC channels are: and

[0052] S5: By processing the data after the two digital downconversion (DDC) channels respectively, two radar echoes with different diversity frequencies can be obtained.

[0053] like Figure 3 , Figure 4 As shown, the traditional method involves a single-channel first mixing followed by two analog channels for mixing. The first intermediate frequency (IF) signal obtained from the first mixing at the receiver is filtered in two paths to separate the target echoes from the two transmission frequencies. The two signals are then converted to second IFs IF1±B / 2 and IF2±B / 2 through their respective analog channels for secondary mixing. The two analog IFs are then converted into digital signals by A / D conversion, and then converted into baseband signals by digital DC conversion in two separate paths. The bandwidth is B, and the corresponding digital local oscillator frequencies are IF1 and IF2, respectively. Although the traditional method can achieve frequency diversity, it is complex in design and has high hardware costs.

[0054] In traditional methods, after the receiver receives the first intermediate frequency (IF), it becomes two analog channels, such as... Figure 5 , Figure 6 As shown, in this embodiment, after the receiver passes through the first intermediate frequency (IF), the receiver remains an analog channel. The frequencies of the two frequency echoes, after passing through the second IF signal following the second mixing, are: The signal is converted from an A / D converter to a digital signal, which is then split into two paths and digitally converted into two baseband signals by digital direct current (DDC). The corresponding digital local oscillator frequencies are respectively... and In this way, the analog channel is completely shared. After AD bandpass sampling and filtering, the reception of radar echoes at two diversity frequencies is realized in the digital channel through DDC. In this embodiment, the analog channel remains a single channel after mixing, sharing the analog channel. The signal is separated and processed in the digital channel field, saving hardware costs, reducing system complexity, and can be extended to other frequency-agile radar designs, making it highly adaptable.

[0055] Example 2

[0056] This embodiment provides a frequency diversity system with a shared analog transceiver channel, including: a signal transmitting unit, a receiver, a mixing unit, an A / D conversion unit, a digital down-conversion unit, and an echo processing unit;

[0057] In this embodiment, the signal transmitting unit is used to continuously transmit multiple signals of different frequencies in a time-division manner;

[0058] In this embodiment, the receiver is used to receive target echoes of different frequencies;

[0059] In this embodiment, the mixing unit is used to mix the target echoes of different frequencies with the first local oscillator signal to obtain the first intermediate frequency signal, and to mix the first intermediate frequency signal with the second local oscillator signal through the same analog receiving channel to obtain the second intermediate frequency signal.

[0060] In this embodiment, the A / D conversion unit is used to convert the second intermediate frequency signal into a digital signal through A / D conversion;

[0061] In this embodiment, the digital down-conversion unit is used to perform digital down-conversion on the digital signal to obtain a digital down-converted output signal;

[0062] In this embodiment, the echo processing unit is used to obtain radar echoes of different diversity frequencies based on the digital down-conversion output signal.

[0063] In this embodiment, the signal transmitting unit is used to continuously transmit multiple signals of different frequencies in a time-division manner, and the frequency signals adopt two linear frequency modulated signals of different frequencies.

[0064] In this embodiment, the frequencies of the linear frequency modulated signals are set to f1±B / 2 and f2±B / 2, where B is the signal bandwidth and f1 and f2 are the center frequencies of the two different frequency signals, respectively.

[0065] In this embodiment, the intermediate frequency of the second intermediate frequency signal is:

[0066]

[0067] Wherein, IF represents the intermediate frequency of the second intermediate frequency signal, B is the signal bandwidth, and f1 and f2 are the center frequencies of the two signals with different frequencies, respectively.

[0068] In this embodiment, the digital down-conversion unit is used to perform digital down-conversion on the digital signal to obtain a digital down-converted output signal. The center frequencies of the digital down-converted output signal are as follows:

[0069] and

[0070] Wherein, IF represents the intermediate frequency of the second intermediate frequency signal, and f1 and f2 are the center frequencies of the two signals with different frequencies.

[0071] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A frequency diversity method for a shared analog transceiver channel, characterized in that, Includes the following steps: Multiple signals of different frequencies are continuously transmitted in a time-division manner, and the frequency signals use two linear frequency modulated signals of different frequencies; The first intermediate frequency (IF) signal is obtained by mixing the target echoes of different frequencies with the first local oscillator signal. The first IF signal is then mixed with the second local oscillator signal through the same analog receiving channel to obtain the second IF signal. The IF frequency of the second IF signal is: ； in, This indicates the intermediate frequency (IF) of the second IF signal. For signal bandwidth, and These are the center frequencies of two signals of different frequencies; The second intermediate frequency signal is converted into a digital signal through an A / D converter; A digital down-conversion is performed on a digital signal to obtain a digital down-converted output signal; Radar echoes at different diversity frequencies are obtained based on the digital down-conversion output signal.

2. The frequency diversity method for a shared analog transceiver channel according to claim 1, characterized in that, The frequency of the linear frequency modulated signal is set to: and ,in, For signal bandwidth, and These are the center frequencies of two signals of different frequencies.

3. The frequency diversity method for a shared analog transceiver channel according to claim 1, characterized in that, Digital down-conversion is performed on the digital signal to obtain the digital down-converted output signal. The center frequencies of the digital down-converted output signal are as follows: and ; in, This indicates the intermediate frequency (IF) of the second IF signal. and These are the center frequencies of two signals of different frequencies.

4. A frequency diversity system sharing a common analog transceiver channel, characterized in that, include: Signal transmitting unit, receiver, mixer unit, A / D conversion unit, digital down-conversion unit, echo processing unit; The signal transmitting unit is used to continuously transmit multiple signals of different frequencies in a time-division manner, and the frequency signals adopt two linear frequency modulated signals of different frequencies; The receiver is used to receive target echoes of different frequencies; The mixing unit is used to mix target echoes of different frequencies with the first local oscillator signal to obtain a first intermediate frequency (IF) signal, and then mix the first IF signal with the second local oscillator signal through the same analog receiving channel to obtain a second IF signal. The IF frequency of the second IF signal is: ； in, This indicates the intermediate frequency (IF) of the second IF signal. For signal bandwidth, and These are the center frequencies of two signals of different frequencies; The A / D conversion unit is used to convert the second intermediate frequency signal into a digital signal through A / D conversion; The digital downconversion unit is used to perform digital downconversion on the digital signal to obtain a digital downconverted output signal. The echo processing unit is used to obtain radar echoes of different diversity frequencies based on the digital down-conversion output signal.

5. The frequency diversity system with a shared analog transceiver channel according to claim 4, characterized in that, The frequency of the linear frequency modulated signal is set to: and ,in, For signal bandwidth, and These are the center frequencies of two signals of different frequencies.

6. The frequency diversity system with a shared analog transceiver channel according to claim 4, characterized in that, The digital down-conversion unit is used to perform digital down-conversion on the digital signal to obtain a digital down-converted output signal. The center frequencies of the digital down-converted output signal are as follows: and ; in, This indicates the intermediate frequency (IF) of the second IF signal. and These are the center frequencies of two signals of different frequencies.

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