A digital phased array communication device wide and narrow band beam alignment method

Abstract

This invention relates to a method for aligning wideband and narrowband beams in a digital phased array communication device. First, a narrowband synchronization header is added to the communication message format. During reception, the digital radio frequency front-end filters the wideband signal received by each antenna element into a narrowband signal, which is then transmitted to the beamforming module through the device's limited internal bandwidth to achieve omnidirectional narrowband beam coverage. The azimuth of the transmitting node is measured using an amplitude comparison method. Next, an attenuation test message is added to the communication message format and transmitted as an amplitude-modulated signal. The received amplitude of the wideband signal is estimated using the amplitude of the received attenuation test message, and the corresponding receive link attenuation coefficient is selected to maximize the received signal-to-noise ratio while satisfying the dynamic requirements of wideband signal reception. Finally, through real-time scheduling by the baseband signal processing module, control parameters such as the wideband beam pointing and the receive link attenuation coefficient are sent to the device module, thereby completing the wideband beam alignment and data reception.

Description

Technical Field

[0001] This invention relates to the field of phased array broadband communication. Background Technology

[0002] Phased array technology, with its flexible beam pointing characteristics, is widely used in the field of communications. With the development of high-speed analog-to-digital sampling chip technology, the front-end of a digital phased array can sample wideband signals with large bandwidths. However, due to limitations in fiber optic transmission technology, it is currently impossible to transmit the wideband signal of each array element from the front-end to the back-end for beamforming, nor can it achieve real-time omnidirectional coverage of the wideband beam. Therefore, when communication nodes are in motion, digital phased array communication equipment can only use prior information to align the wideband receiving beams between communication nodes.

[0003] Prior information methods utilize position information from prior interactions or measurements between communication nodes to calculate their relative positions, thereby achieving receiver beam alignment. However, when the movement speed between communication nodes is too fast and the frequency of measurement interactions is too low, the relative positional error between the communication nodes often becomes too large, making receiver beam alignment impossible. Therefore, communication nodes in rapid motion often require significant network overhead for exchanging position information or performing position measurements to achieve receiver beam alignment. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention proposes a method for aligning wideband and narrowband beams in digital phased array communication equipment. This method incorporates a narrowband synchronization header and attenuation test message into the communication message format, enabling the digital phased array communication equipment to complete the alignment of the wideband receiving beam without prior information.

[0005] This invention provides a method for aligning wide and narrow band beams in a digital phased array communication device, the technical solution of which includes:

[0006] Step 1: Downlink signal narrowbanding; The digital RF front end filters the downlink broadband signals received by all phased array elements into narrowband signals, and performs downconversion and digitization before sending them to the beamforming module;

[0007] Step 2: Narrowband beamforming; The beamforming module performs narrowband beamforming to achieve full-range narrowband beam coverage;

[0008] Step 3: Multi-beam directional channelization narrowband processing; the baseband signal processing module channels the signals received from each narrowband synthesized beam, captures the narrowband synchronization header according to the communication message format, and records the capture time; the processing channel that captures the narrowband synchronization header collects the amplitude value of the attenuation test message according to the communication message format to form an amplitude sequence, and the processing channel that has not captured the synchronization header continues to capture the synchronization header; if all channels have not collected the amplitude value of the attenuation test message, continue to this step; otherwise, proceed to step 4;

[0009] Step 4: Receiver location estimation; Once step 4 is entered, the narrowband synchronization head waiting counter is immediately started. Within the counter's specified time, the attenuation test message amplitude sequence, narrowband synchronization head acquisition time, and beam pointing information collected by each narrowband processing channel are received. When the counter reaches the set threshold, the narrowband receiving beam where the transmitting node is located is determined by using the amplitude sequence collected by each narrowband processing channel through the maximum amplitude method. The selected maximum amplitude is taken as the final narrowband receiving amplitude, and the position of the maximum amplitude in the attenuation test message amplitude sequence is recorded. The beam pointing is taken as the azimuth of the transmitting node, and the narrowband synchronization head acquisition time corresponding to the beam is taken as the final narrowband synchronization head acquisition time.

[0010] Step 5: Estimation of broadband receive link attenuation coefficient; Determine the broadband receive link attenuation coefficient based on the final narrowband received amplitude and its position in the attenuation test message amplitude sequence;

[0011] Step Six: Broadband Receive Beam Control; Based on the location of the transmitting node and the broadband receive link attenuation coefficient, generate corresponding beam control information and send it to each module within the device;

[0012] Step 7: Downlink signal broadbanding; The digital RF front end directly downconverts and digitizes the downlink broadband signals received by all phased array elements;

[0013] Step 8: Broadband beamforming; The digital RF front end completes broadband beamforming of some or all array elements. When there are multiple digital RF front ends in the device, the beamforming module is responsible for broadband beamforming between multiple digital RF front ends.

[0014] Step 9: Broadband signal processing; The baseband signal processing module performs broadband signal processing on the signal received by the broadband beam and captures the broadband synchronization header according to the communication message format;

[0015] Step 10: Determine if the broadband synchronization header acquisition has timed out; based on the final narrowband synchronization header acquisition time and the current time, and in conjunction with the communication message format, determine if the broadband synchronization header acquisition has timed out; if it has timed out, jump back to Step 1, otherwise proceed to Step 11;

[0016] Step 11: Determine if the synchronization header has been captured; determine whether the broadband synchronization header has been captured based on the communication message format. If the synchronization header has been captured, proceed to Step 12; otherwise, return to Step 10.

[0017] Step 12: Broadband data reception and parsing; parse the broadband message according to the communication message format and determine whether the broadband data has been completely received; if the reception is complete, jump back to Step 1, otherwise continue to this step.

[0018] The present invention provides a method for aligning wideband and narrowband beams in a digital phased array communication device. Logically, the digital phased array communication device is divided into a phased array antenna, a digital radio frequency front-end, a beamforming module, and a baseband processing module. Narrowband synchronization headers and attenuation test messages are added to the communication message format, enabling the digital phased array communication device to complete the alignment of the wideband receiving beam without prior information. Attached Figure Description

[0019] Figure 1 Logical composition diagram of digital phased array communication equipment.

[0020] Figure 2 Flowchart of a preferred embodiment of the present invention.

[0021] Figure 3 A schematic diagram of the communication message format.

[0022] Figure 4 Flowchart of the maximum amplitude method. Detailed Implementation

[0023] The present invention will be further explained and described below with reference to the accompanying drawings and embodiments.

[0024] This invention provides a method for broadband and narrowband beam alignment in a digital phased array communication device. First, a narrowband synchronization header is added to the communication message format. During reception, the digital radio frequency front-end filters the broadband signal received by each antenna element into a narrowband signal, which is then transmitted to the beamforming module through the device's limited internal bandwidth for omnidirectional narrowband beam coverage. The azimuth of the transmitting node is measured using an amplitude comparison method. Next, an attenuation test message is added to the communication message format. The received amplitude of the broadband signal is estimated using the amplitude of the received attenuation test message, and the corresponding receive link attenuation coefficient is selected to maximize the received signal-to-noise ratio while satisfying the dynamic requirements of broadband signal reception. Finally, through real-time scheduling by the baseband signal processing module, control parameters such as broadband beam pointing and receive link attenuation coefficient are sent to the device module, thereby completing broadband beam alignment and data reception.

[0025] The flowchart of a preferred embodiment of the present invention is as follows: Figure 2 As shown, the implementation process includes:

[0026] Step 1: Downlink signal narrowbanding; The digital RF front end filters the downlink broadband signals received by all phased array elements into narrowband signals, and performs downconversion and digitization before sending them to the beamforming module;

[0027] Step 2: Narrowband beamforming; The beamforming module performs narrowband beamforming to achieve full-range narrowband beam coverage;

[0028] Step 3: Multi-beam directional channelization narrowband processing; the baseband signal processing module channels the signals received from each narrowband synthesized beam, captures the narrowband synchronization header according to the communication message format, and records the capture time; the processing channel that captures the narrowband synchronization header collects the amplitude value of the attenuation test message according to the communication message format to form an amplitude sequence, and the processing channel that has not captured the synchronization header continues to capture the synchronization header; if all channels have not collected the amplitude value of the attenuation test message, continue to this step; otherwise, proceed to step 4.

[0029] Step 4: Receiver location estimation; Once step 4 is entered, the narrowband synchronization head waiting counter is immediately started. Within the counter's specified time, the attenuation test message amplitude sequence, narrowband synchronization head acquisition time, and beam pointing information collected by each narrowband processing channel are received. When the counter reaches the set threshold, the narrowband receiving beam where the transmitting node is located is determined by using the amplitude sequence collected by each narrowband processing channel through the maximum amplitude method. The selected maximum amplitude is taken as the final narrowband receiving amplitude, and the position of the maximum amplitude in the attenuation test message amplitude sequence is recorded. The beam pointing is taken as the azimuth of the transmitting node, and the narrowband synchronization head acquisition time corresponding to the beam is taken as the final narrowband synchronization head acquisition time.

[0030] Step 5: Estimation of broadband receive link attenuation coefficient; Determine the broadband receive link attenuation coefficient based on the final narrowband received amplitude and its position in the attenuation test message amplitude sequence;

[0031] Step Six: Broadband Receive Beam Control; Based on the location of the transmitting node and the broadband receive link attenuation coefficient, generate corresponding beam control information and send it to each module within the device;

[0032] Step 7: Downlink signal broadbanding; The digital RF front end directly downconverts and digitizes the downlink broadband signals received by all phased array elements;

[0033] Step 8: Broadband beamforming; The digital RF front end completes broadband beamforming of some or all array elements. When there are multiple digital RF front ends in the device, the beamforming module is responsible for broadband beamforming between multiple digital RF front ends.

[0034] Step 9: Broadband signal processing; The baseband signal processing module performs broadband signal processing on the signal received by the broadband beam and captures the broadband synchronization header according to the communication message format;

[0035] Step 10: Determine if the broadband synchronization header acquisition has timed out; based on the final narrowband synchronization header acquisition time and the current time, and in conjunction with the communication message format, determine if the broadband synchronization header acquisition has timed out; if it has timed out, jump back to Step 1, otherwise proceed to Step 11;

[0036] Step 11: Determine if the synchronization header has been captured; determine whether the broadband synchronization header has been captured based on the communication message format. If the synchronization header has been captured, proceed to Step 12; otherwise, return to Step 10.

[0037] Step 12: Broadband data reception and parsing; parse the broadband message according to the communication message format and determine whether the broadband data has been completely received; if the reception is complete, jump back to Step 1, otherwise continue to this step.

[0038] The preferred step three communication message format diagram is shown below. Figure 3 As shown, it consists of a narrowband synchronization header, an attenuation test message, a padding message, a wideband synchronization header, and a wideband message. The narrowband synchronization header uses FSK modulation, which has low demodulation signal-to-noise ratio requirements and strong resistance to saturation distortion. The attenuation test message uses an amplitude-modulated signal, whose amplitude decreases at fixed time intervals until it reaches a minimum value, which can accurately estimate the amplitude of the wideband signal received by the antenna elements and is used to select the correct wideband receiving link attenuation coefficient. The padding message can send a padding signal or no signal, which is used to ensure that the communication equipment completes the distribution and execution of wideband beam control information before receiving the wideband synchronization header. The wideband synchronization header and the wideband message are used to transmit valid wideband data.

[0039] This invention provides a method for wide and narrow band beam alignment in a digital phased array communication device. Logically, the digital phased array communication device is divided into a phased array antenna, a digital radio frequency front-end, a beamforming module, and a baseband processing module. A detailed schematic diagram is shown below. Figure 1 As shown. During reception, the phased array antenna is mainly responsible for receiving radio frequency signals, the digital radio frequency front-end is mainly responsible for down-conversion, digitization, and broadband beamforming of the radio frequency signals, the beamforming module is mainly responsible for narrowband beamforming and broadband beamforming, and the baseband processing module is responsible for broadband and narrowband demodulation, signal processing, and data parsing. During beam control, the baseband processing module is responsible for generating beam control information and sending it to each module in the device. The phased array antenna, digital radio frequency front-end, and beamforming module execute the corresponding control commands.

[0040] The flowchart of the maximum amplitude method in step four of the preferred method is as follows: Figure 4 As shown, it includes:

[0041] (1) Receive amplitude matrixing: When the narrowband synchronization head counter reaches the threshold, the amplitude sequence of the attenuation test messages collected by each narrowband processing channel is aligned and matrixed, with the narrowband processing channel as the row and the collection offset time as the column;

[0042] (2) Read the received amplitude by column, that is, read the amplitude value collected by each narrowband processing channel at the same acquisition offset time;

[0043] (3) Determine whether the sampled amplitude value in this column is valid; determine whether all values ​​in this column are less than the saturation distortion threshold. If so, proceed to step (4); otherwise, proceed to step (5).

[0044] (4) Select the maximum value as the maximum amplitude; select the maximum value by numerical comparison, take the row where the value is located as the best narrowband receiving beam, and take its direction as the location of the transmitting node. Calculate the final narrowband receiving amplitude using the sampling offset time corresponding to the column where the value is located.

[0045] (5) Determine if it is the last column of data. If it is, proceed to step (4); otherwise, proceed to step (6).

[0046] (6) Read the next column of received amplitude values ​​and jump to step (2).

[0047] In the preferred step three, the attenuation test message meets certain constraints. Let the number of symbols in the attenuation test message be n, and the amplitude of the corresponding symbol be A. i , 1≤i≤n; the specific constraints are as follows:

[0048] (1) The time width of each attenuation test message symbol is the same;

[0049] (2) The amplitude of the next symbol is half the amplitude of the previous symbol, as shown in formula (1):

[0050]

Claims

1. A method for wide and narrow band beam alignment in a digital phased array communication device, characterized in that: Step 1: Downlink signal narrowbanding; The digital RF front end filters the downlink broadband signals received by all phased array elements into narrowband signals, and performs downconversion and digitization before sending them to the beamforming module; Step 2: Narrowband beamforming; The beamforming module performs narrowband beamforming to achieve full-range narrowband beam coverage; Step 3: Multi-beam directional channelization narrowband processing; the baseband signal processing module channels the signals received from each narrowband synthesized beam, captures the narrowband synchronization header according to the communication message format, and records the capture time; the processing channel that captures the narrowband synchronization header collects the amplitude value of the attenuation test message according to the communication message format to form an amplitude sequence, and the processing channel that has not captured the synchronization header continues to capture the synchronization header; if all channels have not collected the amplitude value of the attenuation test message, continue to this step; otherwise, proceed to step 4; Step 4: Receive azimuth estimation; Once step 4 is entered, immediately start the narrowband synchronization head waiting counter, and within the counter's specified time, receive the attenuation test message amplitude sequence, narrowband synchronization head acquisition time, and beam pointing information collected by each narrowband processing channel; When the counter reaches the set threshold, the amplitude sequence collected by each narrowband processing channel is used to determine the narrowband receiving beam where the transmitting node is located by the maximum amplitude method. The selected maximum amplitude is the final narrowband receiving amplitude. The position of the maximum amplitude in the attenuation test message amplitude sequence is recorded. The direction of the beam is taken as the location of the transmitting node. The narrowband synchronization header acquisition time corresponding to the beam is taken as the final narrowband synchronization header acquisition time. Step 5: Estimation of broadband receive link attenuation coefficient; Determine the broadband receive link attenuation coefficient based on the final narrowband received amplitude and its position in the attenuation test message amplitude sequence; Step Six: Broadband Receive Beam Control; Based on the location of the transmitting node and the broadband receive link attenuation coefficient, generate corresponding beam control information and send it to each module within the device; Step 7: Broadbanding the downlink signal; The digital radio frequency front end directly down-converts and digitizes the downlink broadband signals received by all phased array elements; Step 8: Broadband beamforming; The digital radio frequency front end completes broadband beamforming of some or all array elements. When there are multiple digital radio frequency front ends in the device, the beamforming module is responsible for broadband beamforming between multiple digital radio frequency front ends. Step Nine: Broadband Signal Processing; The baseband signal processing module performs broadband signal processing on the signals received by the broadband beam and captures the broadband synchronization header according to the communication message format. Step 10: Determine if the broadband synchronization header acquisition has timed out; based on the final narrowband synchronization header acquisition time and the current time, and in conjunction with the communication message format, determine if the broadband synchronization header acquisition has timed out; if it has timed out, jump back to Step 1, otherwise proceed to Step 11; Step 11: Determine if the synchronization header has been captured; determine whether the broadband synchronization header has been captured based on the communication message format. If the synchronization header has been captured, proceed to Step 12; otherwise, return to Step 10. Step 12: Broadband data reception and parsing; parse the broadband message according to the communication message format and determine whether the broadband data has been completely received; If the reception is complete, jump back to step one; otherwise, continue with this step.

2. The method for wide and narrow band beam alignment of a digital phased array communication device according to claim 1, characterized in that: Logically, digital phased array communication equipment is divided into a phased array antenna, a digital radio frequency front-end, a beamforming module, and a baseband processing module. During reception, the phased array antenna is mainly responsible for receiving radio frequency signals, the digital radio frequency front-end is mainly responsible for down-conversion, digitization, and broadband beamforming of the radio frequency signals, the beamforming module is mainly responsible for narrowband beamforming and broadband beamforming, and the baseband processing module is responsible for broadband and narrowband demodulation, signal processing, and data parsing. During beam control, the baseband processing module is responsible for generating beam control information and sending it to each module in the equipment. The phased array antenna, digital radio frequency front-end, and beamforming module execute the corresponding control commands.

3. The method for wide and narrow band beam alignment of a digital phased array communication device according to claim 1, characterized in that: The communication message format in step three consists of a narrowband synchronization header, an attenuation test message, a padding message, a wideband synchronization header, and a wideband message. The narrowband synchronization header uses FSK modulation, which has low demodulation signal-to-noise ratio requirements and strong resistance to saturation distortion. The attenuation test message uses an amplitude-modulated signal, whose amplitude decreases at fixed time intervals until it reaches a minimum value, which can accurately estimate the amplitude of the wideband signal received by the antenna array element and is used to select the correct wideband receiving link attenuation coefficient. The padding message may send a padding signal or no signal, which is used to ensure that the communication equipment completes the distribution and execution of wideband beam control information before receiving the wideband synchronization header. The wideband synchronization header and the wideband message are used to transmit valid wideband data.

4. The method for wide and narrow band beam alignment of a digital phased array communication device according to claim 1, characterized in that: The maximum amplitude method in step four includes: (1) Receive amplitude matrixing: When the narrowband synchronization head counter reaches the threshold, the amplitude sequence of the attenuation test messages collected by each narrowband processing channel is aligned and matrixed, with the narrowband processing channel as the row and the collection offset time as the column; (2) Read the received amplitude by column, that is, read the amplitude value collected by each narrowband processing channel at the same acquisition offset time; (3) Determine whether the sampled amplitude value in this column is valid; determine whether all values ​​in this column are less than the saturation distortion threshold. If so, proceed to step (4); otherwise, proceed to step (5). (4) Select the maximum value as the maximum amplitude; select the maximum value by numerical comparison, take the row where the value is located as the best narrowband receiving beam, and take its direction as the location of the transmitting node. Calculate the final narrowband receiving amplitude using the sampling offset time corresponding to the column where the value is located. (5) Determine if it is the last column of data. If it is, proceed to step (4); otherwise, proceed to step (6). (6) Read the next column of received amplitude values ​​and jump to step (2).

5. The method for wide and narrow band beam alignment of a digital phased array communication device according to claim 1, characterized in that: In step three, the attenuation test message should meet certain constraints. Let the number of symbols in the attenuation test message be n, and the amplitude of the corresponding symbol be A. i , 1≤i≤n; (1) The time width of each attenuation test message symbol must be the same; (2) The amplitude of the next symbol is half the amplitude of the previous symbol, as shown in formula (1):

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