A non-uniform digital channelization method with arbitrary tuning within a wide bandwidth

Abstract

This invention discloses a non-uniform digital channelization method with arbitrary tuning within a wide bandwidth. It employs a multiphase DFT module with dual even-channel arrangement, a channel selection module, and a multi-channel DDC module. The input wideband IQ signal first passes through the multiphase DFT module with dual even-signal arrangement to achieve uniform digital channelization of 16 sub-channels. Then, the channel selection module ensures that the output of each target sub-channel corresponds one-to-one with the actual frequency band. The multi-channel DDC module sets multiple analysis bandwidths for each DDC path through arbitrary decimation filtering, achieving non-uniform channelization with arbitrary tuning within the wide bandwidth. This invention achieves blind-zone-free monitoring of the entire bandwidth, enabling simultaneous acquisition of multiple signals of arbitrary location and bandwidth. The channel selection module enables DDC resource multiplexing, ensuring that the output of each target sub-channel corresponds one-to-one with the actual frequency band. The multiple DDC channels can be arbitrarily tuned within a GHz bandwidth, and multiple analysis bandwidths can be set, achieving flexible non-uniform channelization.

Description

Technical Field

[0001] This invention belongs to the field of channelization monitoring and analysis technology, specifically relating to a non-uniform digital channelization method with arbitrary tuning within a broadband range. Background Technology

[0002] In electronic information environments, signals are distributed over a wide frequency range, with uneven distribution, large bandwidth differences, and inconsistent signal energy. This requires monitoring receivers to have a large bandwidth monitoring capability, the ability to simultaneously acquire multiple signals of arbitrary location and bandwidth, and the ability to accurately analyze signals with different energy levels across multiple channels.

[0003] For simultaneous reception of multiple signals, broadband digital receivers typically employ an analog filter bank channelized reception system or a scheme where multiple digital receivers operate in parallel. However, these two approaches cannot overcome channel imbalance, and at high data rates, small-bandwidth signals require higher-order filters, resulting in huge resource consumption. The system complexity increases with the number of channels, leading to complex equipment composition, high cost, poor scalability, and an inability to adapt to constantly changing new demands.

[0004] Channelization based on polyphase filter banks divides the monitoring bandwidth into several channels with equal bandwidth using an analysis filter. When the signal is at the channel boundary, a monitoring "blind zone" appears due to the transition band of the analysis filter. Simply increasing the filter order can reduce the transition band but cannot fundamentally eliminate the monitoring blind zone. If the passband bandwidth of the analysis filter is increased, the filter's transition band will extend into adjacent channels, causing channel decision ambiguity. Therefore, channelization based on conventional polyphase filter banks cannot simultaneously overcome both the monitoring blind zone and channel ambiguity. Conventional polyphase filter banks determine the number of sub-channels based on the ratio of the input signal rate to the sub-channel passband bandwidth, and then achieve non-uniform channelization by combining adjacent channels through upsampling and synthesis filters. However, the center frequency can only be set at a few fixed frequency points, and the analysis bandwidth can only be set as an integer multiple of the sub-channel bandwidth, lacking flexibility. To achieve a smaller analysis bandwidth, the number of sub-channels needs to be increased, which increases the complexity of the polyphase filter. Summary of the Invention

[0005] To address the aforementioned technical problems in the prior art, this invention provides a non-uniform digital channelization method with arbitrary tuning within a wide bandwidth. The method is rationally designed, overcomes the shortcomings of the prior art, and has good results.

[0006] To achieve the purpose of the invention, the following technical solution is adopted:

[0007] A non-uniform digital channelization method with arbitrary tuning within a wide bandwidth is proposed. It employs a polyphase DFT module with dual even channels, a channel selection module, and a multi-channel DDC module. The input wideband IQ signal first passes through the polyphase DFT module with dual even signals to achieve uniform digital channelization of 16 sub-channels. Then, through the channel selection module, each target channel output is made to correspond one-to-one with the actual frequency band. The DDC path in the multi-channel DDC module is set with multiple analysis bandwidths by decimation filtering of arbitrary multiples to achieve non-uniform channelization with arbitrary tuning within a wide bandwidth.

[0008] Furthermore, the multiphase DFT module includes two even-channel arranged multiphase DFT structures. The zero-IF broadband IQ signal is divided into two paths and input into the two multiphase DFT structures respectively. By shifting the frequency of one of the zero-IF broadband IQ signals by half a channel, it is possible to complete blind-zone-free monitoring of the entire broadband using the multiphase DFT structure with two even signals.

[0009] Furthermore, the multiphase DFT module also includes an IFFT module. The broadband IQ signal outputs 8 parallel data channels through each multiphase DFT structure. The 8 parallel data channels are grouped into an 8*8 output data matrix with 8 clock cycles as a group. After transposing the data matrix, it is input into the IFFT module for parallel computation.

[0010] Furthermore, the monitoring bandwidth is divided into 16 sub-channels with equal bandwidth by an analysis filter. Let the transition band of the analysis filter be x MHz, the maximum demodulation bandwidth be y MHz, and the passband bandwidth of the sub-channel be half of the processing bandwidth plus the maximum demodulation bandwidth.

[0011] Furthermore, the multi-channel DDC module includes 16 parallel DDC paths. The signal selection module selects one of the 16 parallel DDC paths for each target sub-channel according to the output index sequence of the sub-channel, so that the output of each target sub-channel corresponds one-to-one with the actual frequency band.

[0012] Furthermore, the 16 sub-channels are numbered 0-15. Since sub-channels 0, 1, and 15 are within the transition band of the first half-band filter after the ADC, they can be discarded. Only sub-channels 2-14 are selected, that is, the effective sub-channels are numbered 2-14.

[0013] Furthermore, to ensure that the effective channel number and the actual frequency location are consistent, the frequency range of each frequency band is set to "effective channel number * sub-channel bandwidth ± sub-channel bandwidth".

[0014] Furthermore, the number of DDC channels can be increased or decreased according to actual needs. Each DDC channel has independent control parameters. Each DDC channel can accept output data from any subchannel and can perform subsequent operations such as mixing, arbitrary multiple decimation filtering, measurement detection, and demodulation. Multiple analysis bandwidths can be set to achieve non-uniform channelization with arbitrary tuning within the bandwidth.

[0015] The beneficial technical effects of this invention are as follows:

[0016] This invention enables blind-zone-free monitoring of the entire bandwidth, allowing simultaneous acquisition of multiple signals at arbitrary locations and bandwidths; it achieves DDC resource reuse through a channel selection module, ensuring that the output of each target sub-channel corresponds one-to-one with the actual frequency band; multiple DDC channels can be arbitrarily tuned within the GHz bandwidth, and multiple analysis bandwidths can be set to achieve flexible non-uniform channelization. Attached Figure Description

[0017] Figure 1 This is a flowchart of a non-uniform digital channelization method with arbitrary tuning within a broadband range according to the present invention.

[0018] Figure 2 This is a schematic diagram of the polyphase DFT structure with even-channel arrangement in this invention.

[0019] Figure 3 This is a schematic diagram of the channel passband bandwidth design in this invention;

[0020] Figure 4 This is a distribution diagram of the dual even-channel arrangement in this invention;

[0021] Figure 5 This is a schematic diagram of the channel selection module in this invention; Detailed Implementation

[0022] The specific embodiments of the present invention will be further described below with reference to specific examples:

[0023] A non-uniform digital channelization method with arbitrary tuning within a wide bandwidth, such as Figure 1 As shown, a multiphase DFT module with dual even-channel arrangement, a channel selection module, and a multi-channel DDC module are used. The input IQ signal first passes through the multiphase DFT module with dual even-signal arrangement to achieve uniform digital channelization of 16 sub-channels. Then, through the channel selection module, each target sub-channel output is made to correspond one-to-one with the actual frequency band. The DDC path in the multi-channel DDC module is set with multiple analysis bandwidths by decimation filtering of arbitrary multiples to achieve non-uniform channelization with arbitrary tuning within the broadband.

[0024] Digital channelization can be equivalent to a uniform digital filter bank with decimators. Let the number of filters be K, and the decimation ratio be D, satisfying K = FD (F > 0). The center frequency of the even-type channel is ω. k =2πk / K, the center frequency of the odd-shaped channel is ω k =2πk / +π / K. Using even-type and odd-type channelization arrangements respectively, multiphase DFT structures with F=1 channel odd and channel even arrangements are designed. The channels of the two arrangements are interleaved, allowing the multiphase DFT analysis capability to cover the entire broadband bandwidth, thus achieving blind-spot-free monitoring across the entire bandwidth. Let h... LP (n) is an N-1 order FIR low-pass filter with N coefficients, and the center frequency of the kth sub-channel is ω. k Let x p (m)=(mD-p), g p (m)=h LP (mK+p), p=0,1,2,…,K-1, then the output y of the kth sub-channel k (m) is:

[0025]

[0026] Even channel ω k Substituting 2πk / K into the equation and setting D = K = 8, therefore...

[0027]

[0028] Similarly, the output y of the kth sub-channel of the odd channel can be obtained. k (m) is:

[0029]

[0030] in, This is similar to the structure of the even-channel polyphase DFT. Before performing polyphase filtering, it is multiplied by (-1)^m, and each phase output of the polyphase filter is multiplied by its corresponding complex constant. The efficient structure of the even-channel arrangement is more resource-efficient than that of the odd-channel arrangement. Therefore, the even-channel polyphase DFT process can be reused after appropriate adjustments to the polyphase filtering section. The polyphase DFT module contains two even-channel polyphase DFT structures. The 1.5GHz zero-IF broadband IQ signal is split into two paths and input into the two polyphase DFT structures respectively. By shifting the frequency of one of the zero-IF broadband IQ signals by half the channel frequency, it is possible to achieve blind-zone-free monitoring of the entire broadband using the two even-signal polyphase DFT structures. Figure 2 As shown.

[0031] The multiphase DFT module also includes an IFFT module. The wideband IQ signal outputs eight parallel data streams through each multiphase DFT structure. To ensure the IFFT input data is synchronized, the parallel data output from the multiphase filter needs to be aligned before performing the eight-point IFFT. The eight parallel data streams are grouped into an 8x8 output data matrix, each group consisting of eight clock cycles. After transposing the data matrix, it is input into the IFFT module for parallel computation.

[0032] To achieve free tuning of the demodulation bandwidth across the entire bandwidth, it is essential to ensure that the tuning frequency ranges allowed by the dual even-channel arrangement are seamlessly connected, such as... Figure 3 As shown. Channelization based on a polyphase filter bank divides the monitoring bandwidth into 16 sub-channels of equal bandwidth using an analysis filter. Let the transition band of the analysis filter be x MHz and the maximum demodulation bandwidth be y MHz. Then, the untunable frequency range for the odd-channel arrangement is (x + y / 2) MHz, corresponding to the tunable range for the even-channel arrangement is [Fs / 2D - (x + y / 2)]. Since the two frequency bands overlap, (x + y / 2) = [Fs / 2D - (x + y / 2)], resulting in x + y / 2 = Fs / 4D. Therefore, the filter passband bandwidth is Fs / D - 2x = Fs / 2D + y, meaning the passband bandwidth is half the processing bandwidth plus the maximum demodulation bandwidth. The distribution of the channels in the dual even-channel arrangement is shown below. Figure 4 As shown.

[0033] If the data directly enters the DDS path after digital channelization, each DDS path can only accept the output data of a fixed sub-channel. This requires 16 parallel DDC paths to achieve tuning within the bandwidth of one sub-channel. To achieve blind-zone-free detection, 16*16 parallel DDC paths are needed, which is difficult to implement with limited resources. The multi-channel DDC module includes 16 parallel DDC paths. Only 16 parallel DDC paths are needed to achieve blind-zone-free monitoring within the bandwidth. The signal selection module selects one of the 16 parallel DDC paths for each target sub-channel based on the sub-channel output index sequence, ensuring that the output of each target sub-channel corresponds one-to-one with the actual frequency band.

[0034] The 16 sub-channels are numbered 0-15. Since sub-channels 0, 1, and 15 are within the transition band of the first half-band filter after the ADC, they can be discarded. Only sub-channels 2-14 are selected, meaning the effective sub-channels are numbered 2-14. For example... Figure 5 As shown, the channel selection module enables each DDC path to accept output data from any sub-channel.

[0035] Since the input is a zero-IF broadband IQ signal, in order to ensure that the effective channel number and the actual frequency position are consistent, the frequency range of each frequency band is set to "effective sub-channel number * 93.75MHz ± 93.75MHz".

[0036] The host computer selects the output channel data to implement the DDC function. The number of DDC channels can be increased or decreased according to actual needs. Each DDC channel has independent control parameters. Each DDC channel can accept output data from any sub-channel and can perform subsequent operations such as mixing, decimation filtering, measurement detection, and demodulation. Multiple analysis bandwidths can be set to achieve non-uniform channelization with arbitrary tuning within the bandwidth.

[0037] Of course, the above description is not intended to limit the present invention, and the present invention is not limited to the examples given above. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of the present invention should also fall within the protection scope of the present invention.

Claims

1. A non-uniform digital channelization method with arbitrary tuning over a wide bandwidth, characterized in that, The multiphase DFT module with dual even channels, channel selection module, and multi-channel DDC module are used. The input broadband IQ signal first passes through the multiphase DFT module with dual even signals to achieve uniform digital channelization of 16 sub-channels. Then, through the channel selection module, each target sub-channel output is made to correspond one-to-one with the actual frequency band. The DDC path in the multi-channel DDC module is set with multiple analysis bandwidths by decimation filtering of arbitrary multiples to achieve non-uniform channelization of arbitrary tuning within the broadband. The multiphase DFT module contains two even-channel multiphase DFT structures. The zero-IF broadband IQ signal is divided into two paths and input into the two multiphase DFT structures respectively. By shifting the frequency of one of the zero-IF broadband IQ signals by half the frequency of the sub-channel, the multiphase DFT structure with two even signals can be used to complete the blind-zone-free monitoring of the entire broadband. The multiphase DFT module also includes an IFFT module. The broadband IQ signal outputs 8 parallel data channels through each multiphase DFT structure. The 8 parallel data channels are grouped into 8*8 output data matrices with 8 clock cycles as a group. After the data matrix is ​​transposed, it is input into the IFFT module for parallel computation. The monitoring bandwidth is divided into 16 sub-channels with equal bandwidth by an analysis filter. The passband bandwidth of each sub-channel is half of the processing bandwidth plus the maximum demodulation bandwidth. The multi-channel DDC module includes 16 parallel DDC paths. The channel selection module selects one of the 16 parallel DDC paths for each target sub-channel according to the output index sequence of the sub-channel, so that the output of each target sub-channel corresponds one-to-one with the actual frequency band.

2. The non-uniform digital channelization method with arbitrary tuning within a wide bandwidth according to claim 1, characterized in that, The 16 sub-channels are numbered 0-15. Since sub-channels 0, 1, and 15 are in the transition band of the first half-band filter after the ADC, they can be discarded. Only sub-channels 2-14 are selected, that is, the effective sub-channels are numbered 2-14.

3. The non-uniform digital channelization method with arbitrary tuning within a wide bandwidth according to claim 1, characterized in that, To ensure that the effective channel number and the actual frequency location are consistent, the frequency range of each frequency band is set to "effective sub-channel number * sub-channel bandwidth ± sub-channel bandwidth".

4. The non-uniform digital channelization method with arbitrary tuning within a wide bandwidth according to claim 1, characterized in that, The number of DDC channels can be increased or decreased according to actual needs. Each DDC channel has independent control parameters. Each DDC channel can accept output data from any subchannel and can perform mixing, arbitrary multiple decimation filtering, measurement detection and demodulation. Multiple analysis bandwidths can be set to achieve non-uniform channelization with arbitrary tuning within the bandwidth.

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