A millimeter-wave communication unequal bandwidth sub-channel communication method

Abstract

The present invention discloses a millimeter wave communication unequal bandwidth sub-channel communication method, comprising the following steps: firstly, constructing an equal bandwidth sub-channel digital filter group, and implementing the design of an equal bandwidth sub-channel communication transceiver based on the filter group, and then considering the sub-channel merging design, and then constructing an unequal bandwidth sub-channel digital filter group, and implementing the design of an unequal bandwidth sub-channel communication transceiver based on the filter group. The method performs multi-channel unequal channel processing on a large number of received signals, and the sub-channels are non-uniformly divided. Each signal input in the unequal bandwidth sub-channel occupies a sub-band signal with a corresponding different number of channels, which has better flexibility and adaptability than the equal bandwidth sub-channel, and effectively improves the stability of signal transmission.

Description

Technical Field

[0001] The present invention relates to the field of wireless communication technology, and specifically refers to a millimeter-wave communication unequal bandwidth sub-channel communication method. Background Art

[0002] Millimeter-wave communication is an extremely important transmission technology, which has advantages such as high bandwidth, high transmission rate, and high anti-interference performance. Satellite communication can create good conditions for the transmission of broadband information. With the rapid development of millimeter-wave satellite communication, the demand for sub-bandwidth that can receive and send signals is continuously increasing, and it is developing in the directions of multi-channel multi-function and various channel planning.

[0003] Digital channelization is a key technology for processing broadband signals. It uses a parallel method to decompose broadband signals into multiple adjacent sub-bands, performs corresponding digital sampling and signal processing, and finally outputs sub-band signals in segments, which can effectively reduce system pressure and improve the efficiency of broadband signal processing.

[0004] Existing digital channelization methods usually consider the design method of equal bandwidth sub-channels. As a key technology for processing broadband signals, equal bandwidth sub-channel technology has been widely used in fields such as radar, mobile communication, military communication, and radio astronomy. In traditional equal bandwidth sub-channel communication methods, the bandwidths of each sub-channel are evenly divided, and its implementation is simple and stable. However, there are many problems in the actual signal receiving and sending process. In millimeter-wave satellite communication, the input signal changes dynamically and instantaneously, and there will be situations where the number of sub-channel signals, bandwidth, center frequency, and transmission rate are uneven. Therefore, it is necessary to perform multi-channel unequal channel processing on a large number of received signals, and the sub-channels need to be unevenly divided. Each input signal in the unequal bandwidth sub-channel occupies sub-band signals with corresponding different numbers of channels, which has better flexibility and adaptability compared to the equal bandwidth sub-channel. Summary of the Invention

[0005] The present invention proposes a millimeter-wave communication unequal bandwidth sub-channel communication method, which can realize the reception, transmission, demodulation, and analysis of signals on unequal sub-channels, and improve the flexibility of signal receiving and sending in millimeter-wave communication.

[0006] To solve the above technical problems, the technical solution of the present invention is as follows:

[0007] A millimeter-wave communication unequal bandwidth sub-channel communication method includes the following steps:

[0008] S1. Construct an equal bandwidth sub-channel digital filter bank, and the filters in the equal bandwidth sub-channel digital filter bank can be expressed as:

[0009]

[0010] Wherein, is the modulation factor, w k is the center frequency of the k-th subchannel, M is the number of subchannels, and the equal-bandwidth subchannel digital filter bank consists of M filters h k (n). The corresponding filter bank frequency band distribution can be expressed as the original frequency band of the prototype filter being uniformly shifted and covering the entire total frequency band. The frequency band is uniformly divided within the range of 0 to Fs, and the passband bandwidth of each filter obtained by modulation is Fs / M.

[0011] S2. Construct an equal-bandwidth subchannel communication transceiver:

[0012] The equal-bandwidth subchannel communication transceiver includes a transmitter module and a receiver module; the transmitter module consists of interpolation, filtering, and mixing. By inputting the multi-channel signal x k (n) into the transmitter module, the integrated signal s(n) is obtained. The receiver module consists of mixing, filtering, and decimation. By inputting the integrated signal s(n) through the receiver, the reconstructed signal y k (n) is obtained.

[0013] S3. Subchannel merging design, including setting unequal subchannel signals, allocating unequal numbers of subchannels, designing the prototype filter h m (n) corresponding to the unequal-bandwidth subchannel signals, and performing subchannel merging design;

[0014] S4. Construct an unequal-bandwidth subchannel digital filter bank, perform complex exponential modulation on the prototype filter h m (n) corresponding to the unequal subchannel signals to obtain each filter bank respectively. The corresponding filters in each filter bank can be expressed as where represents the i1-th filter obtained by modulating the prototype filter h 0 (n); represents the i2-th filter obtained by modulating the prototype filter h 1 (n). Similarly

[0015] S5. Construct an unequal-bandwidth subchannel communication transceiver. The unequal-bandwidth subchannel communication transceiver includes an unequal-bandwidth transmitter and an unequal-bandwidth receiver. The transmitter includes interpolation, filtering, and mixing, and the receiver includes mixing, filtering, and decimation. By inputting the multi-channel signal into the unequal-bandwidth transmitter, the integrated signal s′(n) is obtained. By inputting the integrated signal s′(n) through the unequal-bandwidth receiver, the final reconstructed signal

[0016] Preferably, the construction method of the equal-bandwidth subchannel digital filter bank:

[0017] S1-1. Perform the following channel normalization division on the digital spectrum of the input signal:

[0018]

[0019] where w k is the center frequency of the k-th sub-channel, M is the number of sub-channels, and Fs is the total bandwidth. When evenly divided into M sub-channels, the interval of each channel is Fs / M. Set the normalized frequency band v f , and the range is set as v f ∈[0 - Fs];

[0020] S1-2. Construct the prototype filter h(n) in the equal-bandwidth channelized digital filter bank;

[0021] S1-3. Construct for the equal-bandwidth sub-channel filter bank. By using the complex exponential modulation method for the prototype filter h 0 (n), select the decimation / interpolation factor D = M. This decimation / interpolation factor is the maximum factor for accurate reconstruction. The filter corresponding to the k-th sub-channel can be expressed as:

[0022]

[0023] where is the modulation factor, w k is the center frequency of the k-th sub-channel, M is the number of sub-channels. The equal-bandwidth sub-channel digital filter bank is composed of M filters h k (n). The corresponding filter bank frequency band distribution can be expressed as the original frequency band of the prototype filter being uniformly shifted and covering the entire total frequency band. Since the normalized frequency band v f is set, the frequency band is evenly divided within the range of 0 to Fs. The passband bandwidth of each filter obtained by modulation is Fs / M. Since in the present invention, the filter corresponding to the k-th sub-channel can also be expressed as:

[0024]

[0025] Preferably, in step S1-2, the design of the low-pass prototype filter h(n) needs to meet the following conditions:

[0026] S1-2-1. The passband bandwidth is B w = Fs / M, and it has a relatively narrow transition band bandwidth. S1-2-2. Meet |H(w)| = 0, that is, it has a high stopband attenuation.

[0027] S1-2-3. To prevent amplitude and phase distortion of the reconstructed signal, the phase-frequency characteristic of the designed prototype filter should have a linear phase.

[0028] Preferably, in step S2, the method for obtaining the integrated signal s(n) by the transmitter is as follows:

[0029] First, the multi-channel signal x k (n) (k = 0, 1, 2,... M-1) is upsampled by M times to sample the signal to a higher sampling frequency, and the signal obtained after upsampling is filtered through h k (n) for sub-channel filtering, orthogonally up-converts the filtered signal, sums each sub-channel signal and outputs to obtain the integrated signal s(n).

[0030] Preferably, in step S2, the method for obtaining the reconstructed signal y k (n) by the receiver is as follows:

[0031] The integrated signal s(n) is divided into M sub-bands, after orthogonal down-conversion and sub-channel filtering, the filtered data stream is downsampled by M times to obtain the reconstructed signal y k (n) (k = 0, 1, 2,... M-1).

[0032] Preferably, step S3 includes the following sub-steps:

[0033] S3-1, setting unequal sub-channel signals;

[0034] Among them, the setting of unequal sub-channel signals is shown in the following formula:

[0035]

[0036] Among them, M is the maximum number of channels, represents the i1-th smallest unmerged sub-channel signal, represents the i2-th channel signal after merging two channels, represents the iM-th channel signal after merging M channels, and the above merged signals are superimposed according to sub-channel signals;

[0037] S3-2, allocating unequal sub-channel numbers. In the actual allocation of unequal sub-channel numbers, for the sum of unequal sub-channel numbers M' = i1 + i2 + … iM, it is necessary to satisfy M' ≤ M, and at the same time, the sum of the bandwidths of each unequal sub-channel is less than or equal to the total allocable bandwidth, and M is the maximum number of sub-channels;

[0038] S3-3, designing the prototype filter h m (n) corresponding to the unequal bandwidth sub-channel signal;

[0039] The prototype filter corresponding to the smallest sub-channel signal is h 0(n), the sub-channel signal after combining two signals The corresponding prototype low-pass filter is h 1 (n). Similarly, for the sub-channel signal after combining M channels The corresponding prototype low-pass filter is h M-1 (n).

[0040] Preferably, the prototype filter h m (n), (m = 0, 1, 2..M-1) satisfies the following conditions:

[0041] The passband bandwidth is The prototype filter h m (n) all have a relatively narrow transition band bandwidth;

[0042] The prototype filter satisfies |H(w)| = 0, that is, it has a high stopband attenuation.

[0043] To prevent amplitude and phase distortion of the reconstructed signal, the phase-frequency characteristics of each designed prototype filter h m (n) should have a linear phase.

[0044] Preferably, in step S5, the method for obtaining the integrated signal s'(n) through the unequal bandwidth transmitter is: First, perform M-fold upsampling on the input signal Then perform sub-channel filtering, perform quadrature upconversion on the filtered signal, sum the corresponding sub-channels and output to obtain the integrated signal s'(n).

[0045] Preferably, in step S5, the method for obtaining the final reconstructed signal through the unequal bandwidth receiver is: Divide the integrated signal s'(n) into M sub-bands, perform quadrature downconversion and sub-channel filtering, and perform M-fold downsampling on the filtered data stream to obtain the reconstructed signal (p = 1, 2,...M)(m = 0, 1, 2,...M-1).

[0046] The present invention has the following characteristics and beneficial effects:

[0047] By adopting the above technical solution, the signal is processed with multiple unequal channels, and the sub-channels are non-uniformly divided. Each input signal in the unequal bandwidth sub-channels occupies sub-band signals with corresponding different numbers of channels, which has better flexibility and adaptability compared with the equal bandwidth sub-channels, and effectively improves the stability of signal transmission.

[0048] The designed transceiver structure for unequal-bandwidth sub-channel communication is complete, the derivation of design parameters is specific, and the design idea is from the equal-bandwidth sub-channel filter bank to the transceiver for unequal-bandwidth sub-channel communication. The design processes of the filter banks and transceiver systems of both are compared accordingly. The simulation results show that the present invention can approximately and accurately reconstruct between the input signal and the reconstructed signal through the unequal-bandwidth sub-channel transceiver, verifying the feasibility of the principle. At the same time, the present invention is applicable to the communication scenario of sending and receiving unequal sub-channel signals, can realize the sending, receiving, demodulation and analysis of signals on the corresponding channels, and improve the flexibility of signal transceiver in millimeter-wave communication. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0050] Figure 1 It is the flowchart of the equal-bandwidth sub-channel design in the embodiment of the present invention;

[0051] Figure 2 It is the flowchart block diagram of the equal-bandwidth sub-channel filter bank design in the embodiment of the present invention;

[0052] Figure 3 It is the structure diagram of the equal-bandwidth sub-channel communication transceiver in the embodiment of the present invention;

[0053] Figure 4 It is the flowchart block diagram of the unequal-bandwidth sub-channel filter bank design in the embodiment of the present invention;

[0054] Figure 5 It is the schematic diagram of the unequal-bandwidth sub-channel communication transceiver in the embodiment of the present invention;

[0055] Figure 6 It is the pulse / magnitude-phase response schematic diagram of the prototype filter h 0 (n) in the simulation experiment of the embodiment of the present invention;

[0056] Figure 7 It is the schematic diagram of the equal-bandwidth sub-channel filter bank in the simulation experiment of the embodiment of the present invention;

[0057] Figure 8 It is the pulse / magnitude-phase response schematic diagram of the prototype filter h 1 (n) in the simulation experiment of the embodiment of the present invention;

[0058] Figure 9 It is the schematic diagram of the unequal-bandwidth sub-channel filter bank in the simulation experiment of the embodiment of the present invention;

[0059] Figure 10 This is a schematic diagram for comparing the input and output signals of a transceiver based on equal-bandwidth sub-channels in the simulation experiment of the embodiment of the present invention;

[0060] Figure 11 This is a schematic diagram for comparing the input and output signals of a transceiver based on unequal-bandwidth sub-channels in the simulation experiment of the embodiment of the present invention. Detailed implementation manners

[0061] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments may be combined with each other.

[0062] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first", "second", etc. may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, the meaning of "a plurality" is two or more.

[0063] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "mounted", "connected", "coupled" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal communication of two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0064] The present invention provides a method for unequal-bandwidth sub-channel communication in millimeter-wave communication, as Figure 1 shown in the flow chart of the design of unequal-bandwidth sub-channels according to a preferred embodiment of the present invention, which includes the following steps:

[0065] First, construct an equal-bandwidth sub-channel digital filter bank, and based on this filter bank, realize the design of the transceiver for equal-bandwidth sub-channel communication. Secondly, consider the sub-channel merging design. Then, construct an unequal-bandwidth sub-channel digital filter bank, and based on this filter bank, realize the design of the transceiver for unequal-bandwidth sub-channel communication.

[0066] Specifically, the design of an equal-bandwidth sub-channel digital filter bank according to a preferred embodiment of the present invention is as follows Figure 2 shown, including the following steps: S1-1. Perform the following channel normalization division on the digital spectrum of the input signal:

[0067]

[0068] where, w k is the center frequency of the k-th sub-channel, M is the number of sub-channels, and Fs is the total bandwidth. When evenly divided into M sub-channels, the interval of each channel is Fs / M. Set the normalized frequency band v f , and the range is set as v f ∈[0 - Fs];

[0069] S1-2. Design the prototype filter h(n) in the equal-bandwidth channelized digital filter bank, where h(n) represents the impulse response of the filter. The filter design needs to meet the following conditions:

[0070] S1-2-1. The passband bandwidth is B w = Fs / M, and it has a narrow transition band bandwidth. The frequency band range of each filter is set to 0 to Fs / M according to the normalized division.

[0071] S1-2-2. The prototype filter needs to satisfy |H(w)| = 0, that is, it has a high stopband attenuation.

[0072] S1-2-3. To prevent amplitude and phase distortion of the reconstructed signal, the phase-frequency characteristic of the designed prototype filter should have a linear phase.

[0073] S1-3. For the design of the equal-bandwidth sub-channel filter bank, by using the complex exponential modulation method for the prototype filter h 0 (n), select the decimation / interpolation factor D = M. This decimation / interpolation factor is the maximum factor for accurate reconstruction. The filter corresponding to the k-th sub-channel can be expressed as:

[0074]

[0075] where, is the modulation factor, w k is the center frequency of the k-th sub-channel, M is the number of sub-channels, and the equal-bandwidth sub-channel digital filter bank is composed of M filters h k (n). The corresponding filter bank frequency band distribution can be expressed as the original frequency band of the prototype filter being evenly shifted and covering the entire total frequency band. Since the normalized frequency band v f, the frequency band is evenly divided within the range of 0 to Fs, and the passband bandwidth of each filter obtained by modulation is Fs / M. Since The filter corresponding to the k-th sub-channel in the present invention can also be expressed as:

[0076]

[0077] It should be noted that a digital filter bank refers to a group of filters with a common input or a common output after addition, and can be divided into a synthesis (receiving) filter bank and an analysis (transmitting) filter bank. The synthesis filter bank is a filter bank with an upsampler, which can synthesize the processed signal, and the analysis filter bank is a filter bank with a downsampler, which can decompose the components of the signal frequency.

[0078] Figure 3 is the structural diagram of the equal-bandwidth sub-channel communication transceiver. As Figure 3 shown, it includes the following transceiver steps:

[0079] S2-1. The transmitter module is composed of interpolation, filtering, and mixing. First, the multi-channel signal x k (m)(k = 0, 1, 2,... M-1) is upsampled by M times (select the decimation / interpolation factor D equal to the number of sub-channels), so that the signal is sampled to a higher sampling frequency. The signal obtained after upsampling is filtered by h k (n) for sub-channel filtering, and the filtered signal is orthogonally upconverted. The signals of each sub-channel are summed and output to obtain the integrated signal s(n).

[0080] Specifically, the formula for the integrated signal s(n) is as follows:

[0081]

[0082] where is the signal obtained after the multi-channel signal x k (i) is upsampled by M times. The specific formula is as follows:

[0083]

[0084] S2-2. The receiver module can be regarded as an approximate inverse process of the transmitter module. The receiver module is composed of mixing, filtering, and decimation. The integrated signal s(n) is divided into M sub-bands, and after orthogonal downconversion and sub-channel filtering, the filtered data stream is downsampled by M times to obtain the reconstructed signal y k (n)(k = 0, 1 ∈ 2 ∈... M-1).

[0085] The formula derivation of the reconstructed signal y k (n) is as follows:

[0086]

[0087] If the input signal x k (n) and the output signal y k (n) satisfy y k (n) = cx k [(n - n c )], where y k (n) is the pure delay signal of x k (n), then the accurate reconstruction of transmission and reception is achieved. Among them, c and n c are both constants.

[0088] Figure 4 is a flowchart of the design of an unequal bandwidth subchannel digital filter bank according to a preferred embodiment of the present invention, as Figure 4 shown, and includes the following steps:

[0089] Based on the equal bandwidth channelization filtering principle, the present invention is further configured as: subchannel merging design, including the following steps:

[0090] S3-1, setting of unequal subchannel signals;

[0091] Among them, the setting of unequal subchannel signals is shown as follows:

[0092]

[0093] Among them, M is the maximum number of channels, represents the i1-th smallest unmerged subchannel signal, represents the i2-th channel signal after the merger of two channels, represents the iM-th channel signal after the merger of M channels, and the above merged signals are realized by superimposing subchannel signals.

[0094] S3-2, allocation of unequal subchannel numbers. In the allocation of unequal subchannel numbers, for the sum of unequal subchannel numbers M' = i1 + i2 +... iM, it is necessary to satisfy M' ≤ M, and at the same time, the sum of the bandwidths of each unequal subchannel is less than or equal to the total allocable bandwidth, and M is the maximum number of subchannels;

[0095] S3-3, designing the prototype filter h m (n) corresponding to the unequal bandwidth subchannel signal;

[0096] The prototype filter corresponding to the smallest subchannel signal is h 0 (n), and the prototype low-pass filter corresponding to the subchannel signal after the merger of two channels is h 1(n), similarly, the sub-channel signals after combining M channels The corresponding prototype filter is h M-1 (n), for the prototype filter h corresponding to unequal-bandwidth sub-channels m (n), (m = 0, 1, 2..M-1) design needs to meet the following conditions:

[0097] S3-3-1, the passband bandwidth is The prototype filter h m (n) all have a relatively narrow transition-bandwidth;

[0098] S3-3-2, the prototype filter h m (n) satisfies |H(w)| = 0, that is, it has a high stop-band attenuation.

[0099] S3-3-3, to prevent amplitude and phase distortion of the reconstructed signal, the designed prototype filters h m (n) should have a linear phase-frequency characteristic.

[0100] S4, perform complex exponential modulation on the prototype filter h for unequal sub-channel number allocation m (n) to obtain each filter bank respectively. The corresponding filters in each filter bank can be expressed as where represents the i1-th filter modulated by the prototype filter h o (n), represents the i2-th filter modulated by the prototype filter h 1 (n). Similarly In actual settings, there is no case where each prototype filter h m (n) is modulated, because it is necessary to meet the above-mentioned unequal sub-channel number allocation and total bandwidth allocation. The setting of the filter bank should cover the entire frequency band as much as possible, and the passband bandwidths between adjacent filter banks should be as close as possible to reduce the influence of the overlapping part of the channels on the reconstruction accuracy of the output signal, and at the same time it is also convenient to optimize the discrimination between cross-sub-channel signals.

[0101] Figure 5 is the structure diagram of an ideal unequal-bandwidth sub-channel communication transceiver. As Figure 5 shown, it includes the following transceiver steps:

[0102] S5-1, for the unequal-bandwidth transmitter structure, also select the decimation / interpolation factor D equal to the number of sub-channel channels M. First, perform M-fold upsampling on the input signal , then perform sub-channel filtering, realize quadrature upconversion on the filtered signal, and sum and output the corresponding sub-channels to obtain the integrated signal s'(n).

[0103] The derivation of the integrated signal s′(n) formula is as follows:

[0104]

[0105] (M′ = i1 + i2 + … iM ≤ M),

[0106] where is the baseband signal The signal obtained after M-fold upsampling can be expressed as:

[0107]

[0108] S5-2. The receiver module can be regarded as an approximate inverse process of the transmitter module. The receiver module consists of the final mixing, filtering, and decimation. The integrated signal s′(n) is divided into M sub-bands. After quadrature down-conversion and sub-channel filtering, the filtered data stream is decimated by M to obtain the reconstructed signal (p = 1, 2,... M)(m = 0, 1, 2, M - 1).

[0109] The reconstructed signal The formula derivation is as follows:

[0110]

[0111] where represents the ip-th filter corresponding to the prototype filter h m (n) after complex exponential modulation.

[0112] If the input signal and the output signal satisfy where is the pure delay signal of, then accurate reconstruction of the transceiver is achieved. Among them, c and n c are both constants.

[0113] Furthermore, in this embodiment, the technical solution of the present invention is specifically described and illustrated through a specific case:

[0114] The present invention is further provided. Among them, for the equi-bandwidth filter bank setting, the normalized frequency band v f The range is set as v f ∈[0 - 80MHz], the number of sub-channels is M = 8, and the total bandwidth is Fs = 80MHz. When evenly divided into 8 sub-channels, the channel interval is 10MHz.

[0115] Figure 6 describes the prototype low-pass filter h 0(n)'s impulse response and amplitude-phase response are designed using the filter design tool in Matlab during the simulation experiment. The design method uses the FIR Hamming window, the filter order is set to 80, the filter passband bandwidth is set to 10 MHz, and the sampling frequency is set to 80 MHz. It can be observed from the figure that the prototype filter h 0 (n) has a linear phase, and has a large stopband attenuation and a narrow transition band bandwidth. The stopband attenuation is about 60 dB, meeting the theoretical design requirements.

[0116] Figure 7 Describes the equal-bandwidth sub-channel filter bank settings. Considering resource consumption during the simulation experiment, the filter bank adopts an overlapping channel bandwidth design method, and the normalized frequency band is set to v f ∈[0 - 80 MHz], the number of channels is set to M = 8, the channel spacing is 10 MHz, and the center frequencies of the sub-channels are as follows:

[0117] w 0 = 5 MHz, w 1 = 15 MHz, w 2 = 25 MHz, w 3 = 35 MHz

[0118] w 4 = 45 MHz, w 5 = 55 MHz, w 6 = 65 MHz, w 7 = 75 MHz

[0119] Among them, for the sub-channel merging design, set is expressed as 4 minimum unmerged sub-channel signals, is expressed as 2 sub-channel signals after merging two channels, and the merged signal is achieved by superimposing the sub-channel signals. For unequal sub-channel allocation, the sum of the above unequal sub-channel numbers M' = 6, satisfying M' ≤ M, M = 8 is the maximum number of sub-channels, the frequency band range is 0 - 40 MHz, the frequency band range is 40 - 80 MHz, reasonably allocating the total bandwidth to meet the theoretical requirements.

[0120] Figure 8 Describes the impulse response and amplitude-phase response of the prototype low-pass filter h 1 (n). The design is carried out using the filter design tool in Matlab during the simulation experiment. The design method uses the FIR Hamming window, the filter order is set to 80, the filter passband bandwidth is set to 20 MHz, and the sampling frequency is set to 80 MHz. It can be observed from the figure that the prototype filter h 1(n) has a linear phase, and has a large stopband attenuation and a narrow transition band bandwidth. The stopband attenuation is about 60 dB, meeting the theoretical design requirements.

[0121] Figure 9 Describes the unequal bandwidth sub-channel filter bank setting. In the simulation experiment, considering resource consumption, the same type of filter bank adopts the design method of overlapping channel bandwidth, and the normalized frequency band is set to v f ∈[0 - 80 MHz], the sum of the unequal sub-channel numbers is set to M' = 6, and the filter bank The frequency band interval between is 10 MHz, and the filter bank The frequency band interval between is 20 MHz. The center frequencies of the sub-channels are as follows:

[0122] w 0 = 5 MHz, w 1 = 15 MHz, w 2 = 25 MHz

[0123] w 3 = 35 MHz, w 4 = 50 MHz, w 5 = 70 MHZ

[0124] Figure 10 Describes the comparison between the input signal and the output signal of the equal bandwidth sub-channel transceiver in the simulation experiment. The input signal is a chirp signal modulated by a complex exponential. There is no signal distribution in channels 1 and 8, and the input signals are located in channels 2, 3, 4, 5, 6, and 7 respectively. Observing the simulation experiment results, it can be seen that under the structure of the equal bandwidth sub-channel communication transceiver, the frequency band positions of the input signal and the output signal are the same, and there are slight differences in amplitude, achieving approximate accurate reconstruction.

[0125] Figure 11 Describes the comparison between the input signal and the output signal of the unequal bandwidth sub-channel transceiver in the simulation experiment. The input signal is a chirp signal modulated by a complex exponential. There is no signal distribution in channel 1, and channels 5 and 6 are the merged channels after the merger of two channels. Channels 1, 2, 3, and 4 are the smallest sub-channels, and the input signals are located in channels 2, 3, 4, 5, and 6 respectively. Observing the simulation experiment results, it can be seen that under the structure of the unequal bandwidth sub-channel communication transceiver, the frequency band positions of the input signal and the output signal are the same, and there are slight differences in amplitude, achieving approximate accurate reconstruction.

[0126] The above has described the embodiments of the present invention in detail with reference to the accompanying drawings, but the present invention is not limited to the described embodiments. For those skilled in the art, without departing from the principle and spirit of the present invention, various changes, modifications, substitutions, and variations to these embodiments including components still fall within the protection scope of the present invention.

Claims

1. A millimeter-wave communication unequal-bandwidth sub-channel communication method, characterized in that, it includes the following steps: S1. Construct an equal-bandwidth sub-channel digital filter bank, and the filters in the equal-bandwidth sub-channel digital filter bank can be expressed as: Among them, is the modulation factor, w k is the center frequency of the k-th subchannel, M is the number of subchannels, and the equal-bandwidth subchannel digital filter bank is composed of M filters h k (n). The corresponding filter bank frequency band distribution can be expressed as the original frequency band of the prototype filter being uniformly shifted and covering the entire total frequency band. The frequency band is uniformly divided within the corresponding range, and the passband bandwidths of the filters obtained by modulation are all equal. S2. Construct an equal-bandwidth sub-channel communication transceiver: The equal-bandwidth sub-channel communication transceiver includes a transmitter module and a receiver module; the transmitter module consists of interpolation, filtering, and mixing. By inputting the multi-channel signal x k (n) into the transmitter module, an integrated signal s(n) is obtained. The receiver module consists of mixing, filtering, and decimation. By inputting the integrated signal s(n) into the receiver, a reconstructed signal y k (n) is obtained; S3. Sub-channel merging design, including unequal sub-channel signal setting, unequal sub-channel number allocation, and designing the prototype filter h m (n) corresponding to the unequal bandwidth sub-channel signals for sub-channel merging design; S3-1. Unequal sub-channel signal setting; Among them, the unequal sub-channel signal setting is shown in the following formula: where M is the maximum number of channels, represents the i1-th smallest sub-channel signal that has not been merged, represents the i2-th channel signal after the merger of two channels, represents the iM-th channel signal after the merger of M channels, and the merged signal is realized by superimposing sub-channel signals; S3-2. Unequal sub-channel number allocation. In the allocation of unequal sub-channel numbers, for the sum of unequal sub-channel numbers M′ = i1 + i2 + … iM, it is required to satisfy M′ ≤ M, and at the same time, the sum of the bandwidths of each unequal sub-channel is less than or equal to the total allocable bandwidth, and M is the maximum number of sub-channels; S3-3. Design the prototype filter h corresponding to the unequal bandwidth sub-channel signal m (n); Minimum sub-channel signal The corresponding prototype filter is h 0 (n), and the sub-channel signal after combining two channels The corresponding prototype filter is h 1 (n). Similarly, the sub-channel signal after combining M channels The corresponding prototype filter is h M-1 (n); S4. Construct an unequal-bandwidth sub-channel digital filter bank, and perform complex exponential modulation on the prototype filter h m (n) corresponding to the unequal sub-channel signals to obtain each filter bank respectively. The corresponding filters in each filter bank can be expressed as where represents the i1-th filter modulated from the prototype filter h 0 (n), represents the i2-th filter modulated from the prototype filter h 1 (n). Similarly S5. Construct an unequal-bandwidth sub-channel communication transceiver, which includes an unequal-bandwidth transmitter and an unequal-bandwidth receiver. The transmitter includes interpolation, filtering, and mixing, and the receiver includes mixing, filtering, and decimation. By inputting a multi-channel signal into the unequal-bandwidth transmitter, an integrated signal s′(n) is obtained. The input integrated signal s′(n) passes through the unequal-bandwidth receiver to obtain the final reconstructed signal 2. The millimeter-wave communication unequal-bandwidth sub-channel communication method according to claim 1, characterized in that, the construction method of the equal-bandwidth sub-channel digital filter bank: S1-1. Perform the following channel normalization division on the digital spectrum of the input signal: where, w k is the center frequency of the k-th sub-channel, M is the number of sub-channels, Fs is the total bandwidth. When evenly divided into M sub-channels, the interval of each channel is Fs / M. Set the normalized frequency band v f , and the range is set as v f ∈[0 - Fs]; S1-2. Construct the prototype filter h(n) in the equal-bandwidth channelized digital filter bank; S1-3. Construct an equal-bandwidth sub-channel filter bank. By using the complex exponential modulation method for the prototype filter h 0 (n), select the decimation / interpolation factor D = M. This decimation / interpolation factor is the maximum factor for accurate reconstruction. The filter corresponding to the k-th sub-channel can be expressed as: Since In the present invention, the filter corresponding to the k-th sub-channel can also be expressed as:

3. The millimeter-wave communication unequal-bandwidth sub-channel communication method according to claim 2, characterized in that, in S1-2, the design of the prototype filter h(n) needs to meet the following conditions: S1-2-1, the passband bandwidth is B w = Fs / M, and has a relatively narrow transition band bandwidth; S1-2-2. Satisfy |H(w)| = 0, that is, have a high stopband attenuation.

4. The millimeter-wave communication unequal-bandwidth sub-channel communication method according to claim 3, characterized in that, in S2, the method for obtaining the integrated signal s(n) through the transmitter is: First, perform M-fold upsampling on the multi-channel signal x k (n) (k = 0, 1, 2,... M-1) to sample the signal to a higher sampling frequency, and the signal obtained after upsampling is filtered through h k (n) for sub-channel filtering, orthogonally up-convert the filtered signal, sum the signals of each sub-channel and output to obtain the integrated signal s(n).

5. The millimeter-wave communication unequal-bandwidth sub-channel communication method according to claim 4, characterized in that, In the above S2, the reconstructed signal y is obtained through a receiver k (n) is as follows: The integrated signal s(n) is divided into M sub-bands. After orthogonal down-conversion and sub-channel filtering, the filtered data stream is down-sampled by M times to obtain the reconstructed signal y k (n) (k = 0, 1, 2,... M-1).

6. The millimeter-wave communication unequal-bandwidth sub-channel communication method according to claim 5, characterized in that, The prototype filter h m (n), (m = 0, 1, 2..M-1) satisfies the following conditions: The passband bandwidth is The prototype filter h m (n) both have a relatively narrow transition-bandwidth; Prototype filter h m (n) satisfies |H(w)|, that is, it has a high stopband attenuation.

7. The millimeter-wave communication unequal-bandwidth sub-channel communication method according to claim 6, characterized in that, In S5, the method for obtaining the integrated signal s′(n) through an unequal bandwidth transmitter is as follows: First, the input signal is upsampled by M times, then sub-channel filtering is performed, the filtered signal is orthogonally up-converted, and the corresponding sub-channels are summed and output to obtain the integrated signal s′(n).

8. The millimeter-wave communication unequal-bandwidth sub-channel communication method according to claim 7, characterized in that, In S5, the final reconstructed signal is obtained through a receiver with unequal bandwidths. The method is as follows: The integrated signal s′(n) is divided into M sub-bands. After quadrature down-conversion and sub-channel filtering, the filtered data stream is decimated by a factor of M to obtain the reconstructed signal.

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