Interference suppression method and device

Abstract

The invention relates to the technical field of communication, and provides an interference suppression method and device. The method comprises the following steps: determining time offset according to channel quality; determining the positions of a rising window and a falling window in an OFDM symbol according to the time offset; and performing windowing processing according to the ascending window and the descending window to generate an OFDM symbol after interference suppression. According to the embodiment of the invention, the windowing position can be dynamically adjusted, so that the demodulation performance and the out-of-band leakage suppression capability are improved.

Description

Technical Field

[0001] This specification relates to the field of communication technologies, and in particular, to an interference suppression method and apparatus. Background Art

[0002] In related technologies, an Orthogonal Frequency Division Multiplexing (OFDM) receiver intercepts a time-domain received signal with a rectangular window and then performs a Fast Fourier Transform operation. Among them, the interception of the rectangular window in the time domain is equivalent to the convolution of the sinc function in the frequency domain, and the sinc function will cause adjacent non-orthogonal signals to leak into the current rectangular window.

[0003] In the prior art, as shown in the attached Figure 1 By applying a smooth rising window at the boundary between the cyclic prefix and the FFT symbol part of the OFDM symbol (half of the smooth rising window is within the cyclic prefix and the other half is within the OFDM symbol), and applying a smooth falling window at the boundary between the OFDM symbol and the cyclic suffix (half of the smooth falling window is within the OFDM symbol and the other half is within the cyclic suffix), and at the same time, superimposing the rising window part at the tail of the cyclic prefix on the falling window part at the tail of the OFDM symbol, and superimposing the falling window part of the cyclic suffix on the rising window part at the head of the OFDM symbol, to cancel the in-symbol distortion caused by windowing at the head and tail of the OFDM symbol and restore the orthogonality between subcarriers within the OFDM symbol. The superimposing processes are respectively as shown by the two arrows in Figure 1 However, in the prior art, in addition to the cyclic prefix, a cyclic suffix is also required to be added to the OFDM symbol, and two windowing operations and two summing operations need to be performed at fixed positions at the head and tail respectively, resulting in a relatively high computational complexity and limited demodulation performance and out-of-band leakage suppression ability.

[0004] Therefore, there is an urgent need for an interference suppression method to improve the demodulation performance and out-of-band leakage suppression ability. Summary of the Invention

[0005] In view of the defects in the prior art that the OFDM receiver has a high computational complexity cost and poor out-of-band leakage suppression ability, embodiments of this specification provide an interference suppression method and apparatus to overcome or at least partially solve the above problems.

[0006] On the one hand, some embodiments of this specification aim to provide an interference suppression method, and the method includes:

[0007] Determine a time offset according to the channel quality;

[0008] Determine the positions of the rising window and the falling window in the OFDM symbol according to the time offset;

[0009] Windowing processing is performed according to the rising window and the falling window to generate an OFDM symbol after interference suppression.

[0010] Further, before determining the time offset according to the channel quality, it further includes:

[0011] Measure the multi-path channel delay distribution measurement information of the time-domain received signal.

[0012] Further, determining the time offset according to the channel quality includes:

[0013] Analyze the weight of at least one measurement value in the multi-path channel delay distribution measurement information of the time-domain received signal;

[0014] Use the weight to perform weighted calculation on the multi-path channel delay distribution measurement information to obtain the time offset.

[0015] Further, determining the positions of the rising window and the falling window in the OFDM symbol according to the time offset includes:

[0016] Obtain a first offset segment according to the tail of the OFDM symbol and the time offset;

[0017] Obtain a second offset segment according to the tail of the cyclic prefix offset of the OFDM symbol and the time offset;

[0018] The rising window is adjacent to the second offset segment in the cyclic prefix offset, and the falling window is adjacent to the first offset segment.

[0019] Further, after determining the positions of the rising window and the falling window in the OFDM symbol according to the time offset, it further includes:

[0020] Determine the window lengths of the rising window and the falling window according to the cyclic prefix offset and the time offset.

[0021] Further, determining the window lengths of the rising window and the falling window according to the cyclic prefix offset and the time offset further includes:

[0022] Determine the difference between the cyclic prefix offset and the time offset;

[0023] Determine the window lengths of the rising window and the falling window according to the difference.

[0024] Further, determining the difference between the cyclic prefix offset and the time offset includes:

[0025] Map the time offset to obtain a sample point offset;

[0026] Obtain a corresponding difference value according to the cyclic prefix offset and the sample offset.

[0027] Further, map the time offset to obtain a sample offset, including:

[0028] Obtain the frame structure information corresponding to the OFDM symbol;

[0029] Use the frame structure information to map the time offset in the time domain to the sample offset in the sample domain.

[0030] Further, perform windowing processing according to the rising window and the falling window to generate an OFDM symbol after interference suppression, including:

[0031] Perform windowing on the rising window and the falling window, and superimpose the windowing result of the rising window on the windowing result of the falling window to generate an OFDM symbol after interference suppression.

[0032] Further, perform windowing on the rising window and the falling window, and superimpose the windowing result of the rising window on the windowing result of the falling window to generate an OFDM symbol after interference suppression, including:

[0033] Obtain a rising window coefficient and a falling window coefficient that meet preset conditions;

[0034] Perform windowing on the rising window according to the rising window coefficient, and perform windowing on the falling window according to the falling window coefficient;

[0035] Superimpose the windowing result of the rising window on the windowing result of the falling window to obtain a superimposed result;

[0036] Generate an OFDM symbol after interference suppression according to the superimposed result.

[0037] Further, the preset conditions include: the sum of the coefficients of the corresponding samples in the rising window and the falling window is a preset value.

[0038] Further, after generating an OFDM symbol after interference suppression according to the superimposed result, it further includes:

[0039] Remove the cyclic prefix offset of the OFDM symbol after interference suppression.

[0040] Further, after removing the cyclic prefix offset of the OFDM symbol after interference suppression, it further includes:

[0041] Perform a fast Fourier transform on the OFDM symbol after removing the cyclic prefix offset.

[0042] Further, after generating an OFDM symbol after interference suppression according to the superimposed result, it further includes:

[0043] Generate a target sequence after interference suppression based on the OFDM symbol after interference suppression.

[0044] Furthermore, before outputting the target sequence according to the OFDM symbol after interference suppression, it further includes:

[0045] Perform time delay compensation on the current OFDM symbol according to the time offset.

[0046] On the other hand, some embodiments of this specification also provide a receiving end, including:

[0047] A measurement unit for measuring the channel quality;

[0048] A processor for determining the time offset according to the channel quality; determining the positions of the rising window and the falling window in the OFDM symbol according to the time offset; and performing windowing processing according to the rising window and the falling window to generate an OFDM symbol after interference suppression.

[0049] On the other hand, some embodiments of this specification also provide a computer device, including a memory, a processor, and a computer program stored on the memory. When the computer program is run by the processor, it executes the instructions of the above method.

[0050] On the other hand, some embodiments of this specification also provide a computer storage medium, on which a computer program is stored. When the computer program is run by the processor of a computer device, it executes the instructions of the above method.

[0051] On the other hand, some embodiments of this specification also provide a computer program product, which includes a computer program. When the computer program is run by the processor of a computer device, it executes the instructions of the above method.

[0052] One or more technical solutions provided by some embodiments of this specification have at least the following technical effects:

[0053] As can be seen from the technical solutions provided by the embodiments of this specification above, the embodiments of this specification can, according to the current communication environment, determine the time offset according to the channel quality, and determine the positions of the rising window and the falling window in the OFDM symbol according to the time offset, so that when windowing the rising window and the falling window to generate an OFDM symbol after interference suppression, it can be realized that the windowing positions are dynamically adjusted according to different communication environments, improving the demodulation performance and enhancing the out-of-band leakage suppression ability.

[0054] The above description is only an overview of the technical solutions of some embodiments of this specification. In order to be able to more clearly understand the technical means of some embodiments of this specification, it can be implemented according to the content of the specification. And in order to make the above and other purposes, features and advantages of some embodiments of this specification more obvious and understandable, the following specifically presents the specific implementation manners of some embodiments of this specification. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] In order to more clearly illustrate the technical solutions in some embodiments of this specification or the prior art, the following will briefly introduce the drawings required to be used in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments recorded in this specification. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings. In the drawings:

[0056] Figure 1 shows a schematic diagram of the signal processing process for interference suppression in the prior art in some embodiments of this specification;

[0057] Figure 2 shows a schematic diagram of the implementation system of an interference suppression method in some embodiments of this specification;

[0058] Figure 3 shows another schematic diagram of the implementation system of an interference suppression method in some embodiments of this specification;

[0059] Figure 4 shows a flowchart of an interference suppression method in some embodiments of this specification;

[0060] Figure 5 is a schematic diagram of the steps for determining the time offset of an OFDM symbol in the current communication environment in some embodiments of this specification;

[0061] Figure 6 is a schematic diagram of the steps for determining the positions of the rising window and the falling window in an OFDM symbol in some embodiments of this specification;

[0062] Figure 7 is a schematic diagram of the structure of an OFDM symbol before windowing in some embodiments of this specification;

[0063] Figure 8 is a schematic diagram of the steps for determining the window lengths of the rising window and the falling window according to the cyclic prefix offset and the time offset in some embodiments of this specification;

[0064] Figure 9 is a schematic diagram of the steps for determining the difference between the cyclic prefix offset and the time offset in some embodiments of this specification;

[0065] Figure 10 Schematic diagram of steps for mapping time offset to obtain sample point offset in some embodiments of this specification;

[0066] Figure 11 Schematic diagram of steps for generating an OFDM symbol after interference suppression in some embodiments of this specification;

[0067] Figure 12a Schematic diagram of the process of superimposing the windowing result of the rising window onto the windowing result of the falling window in some embodiments of this specification;

[0068] Figure 12b Schematic diagram of the process of superimposing the windowing result of the rising window onto the windowing result of the falling window in some embodiments of this specification;

[0069] Figure 13 Schematic diagram of the structure of a receiving end in some embodiments of this specification.

[0070]

Explanation of attached drawing reference numerals

[0071] 101, receiving end;

[0072] 102, transmitting end;

[0073] 1301, measuring unit;

[0074] 1302, processor. Detailed implementation manners

[0075] In order to enable those skilled in the art of this technology to better understand the technical solutions in this specification, the following will clearly and completely describe the technical solutions in the embodiments of this specification in conjunction with the attached drawings in some embodiments of this specification. Obviously, the described embodiments are only some embodiments of this specification, rather than all embodiments. Based on some embodiments in this specification, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the scope of protection of this specification.

[0076] It should be noted that the terms "first", "second", etc. in the description, claims and attached drawings of this article are used to distinguish similar objects, and do not necessarily have to be used to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, device, product or equipment that includes a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or equipment.

[0077] It should be noted that the acquisition, storage, use, processing, etc. of data in the technical solution of this application all comply with the relevant regulations of relevant laws and regulations.

[0078] It should be noted that in the embodiments of this specification, when certain software, components, models and other industry-existing solutions are mentioned, they should be regarded as exemplary. The purpose is only to illustrate the feasibility in the implementation of the technical solution of this application, but it does not mean that this solution must be used.

[0079] As Figure 3 shown in the schematic diagram of the implementation system of an interference suppression method according to an embodiment of the present invention, it may include: a receiving end 101 and a transmitting end 102. The receiving end 101 and the transmitting end 102 communicate through an intermediate channel. After the transmitting end 102 sends out a signal, the signal reaches the receiving end 101 through the intermediate channel, so that the receiving end 101 obtains the corresponding time-domain received signal from the transmitting end 102 and performs calculation processing on the corresponding time-domain received signal to obtain a processing result.

[0080] Among them, the transmitting end 102 includes but is not limited to devices such as microphones, cameras, satellites, and smart terminals, and the receiving end 101 includes but is not limited to devices such as speakers, displays, and smart terminals. This is not limited herein.

[0081] In addition, it should be noted that Figure 2 shown is only an application environment provided by this disclosure. In actual applications, referring to the attached Figure 3 , it may also include multiple receiving ends 101, which are not limited in this specification.

[0082] Figure 4 is a flowchart of an interference suppression method provided by an embodiment of the present invention. This specification provides the method operation steps as described in the embodiment or flowchart, but based on routine or non-creative labor, it may include more or fewer operation steps. The step sequence listed in the embodiment is only one way among the execution sequences of many steps and does not represent the only execution sequence. When the actual system or device product executes, it can be executed in the method sequence shown in the embodiment or the drawings or executed in parallel. Specifically, as Figure 4 shown, applied to the receiving end side described above, the method may include:

[0083] S401: Determine the time offset according to the channel quality;

[0084] S402: Determine the positions of the rising window and the falling window in the OFDM symbol according to the time offset;

[0085] S403: Perform windowing processing according to the rising window and the falling window to generate an OFDM symbol after interference suppression.

[0086] As can be seen from the technical solutions provided in the embodiments of this specification above, the embodiments of this specification can determine the time offset according to the channel quality for the current communication environment, and determine the positions of the rising window and the falling window in the OFDM symbol according to the time offset, so that when windowing the rising window and the falling window to generate an OFDM symbol after interference suppression, the windowing positions can be dynamically adjusted according to different communication environments, improving the demodulation performance and enhancing the out-of-band leakage suppression ability.

[0087] It can be understood that in some embodiments, different communication environments have different wireless channel environments or wireless modulation frequency bands, etc. In different wireless channel environments, there are corresponding different delay spreads and multipath information distributions. In the same wireless channel environment, different wireless modulation frequency bands also correspond to different delay spreads and multipath information distributions. Therefore, when performing demodulation, it is necessary to perform flexible windowing processing on the time-domain received signal according to the differences between different communication environments.

[0088] Specifically, in some embodiments, the differences between communication environments can be measured according to the channel quality, and the channel quality can include channel quality parameters such as multipath channel delay distribution measurement information. Before determining the time offset according to the channel quality, it is necessary to measure the channel quality parameters such as the multipath channel delay distribution measurement information of the time-domain received signal to obtain the channel quality parameters such as the multipath channel delay distribution measurement information. Taking the multipath channel delay distribution measurement information as an example, in some embodiments, the multipath channel delay distribution measurement information can include one or more of the first-path delay measurement value, the strongest-path delay measurement value, the tail-path delay measurement value, the weighted-path delay measurement value, and the delay spread measurement value of the multipath channel, which is not limited herein.

[0089] After obtaining the multipath channel delay distribution measurement information of the time-domain received signal, referring to Appendix Figure 5 , in some embodiments, determining the time offset according to the channel quality may include:

[0090] S501: Analyze the weight occupied by at least one measurement value in the multipath channel delay distribution measurement information of the time-domain received signal;

[0091] S502: Use the weight to perform weighted calculation on the multipath channel delay distribution measurement information to obtain the time offset.

[0092] It can be understood that in some embodiments, since the multi-path channel delay distribution measurement information can be composed of multiple measurement values, but not all measurement values have an important impact or any impact on the time offset of the OFDM symbol in the current communication environment. Therefore, it is necessary to analyze the weight of at least one measurement value in the multi-path channel delay distribution measurement information of the time-domain received signal. Specifically, in some embodiments, the weight analysis methods are mainly divided into two ways: online analysis and offline analysis, aiming to adjust the weight of each measurement value. The commonly used online analysis methods include weighting based on instantaneous signal-to-noise ratio and LMS filtering, etc. The commonly used offline analysis methods include maximum likelihood estimation method and weight allocation method based on clustering, etc. This is not limited in this article. Since online analysis and offline analysis are prior arts and not the focus of the invention in this specification, they will not be elaborated here.

[0093] Furthermore, by using the analyzed weight to perform weighted calculation on the multi-path channel delay distribution measurement information, the time offset of the OFDM symbol in the current communication environment can be obtained quickly and accurately. The specific weighted calculation formula is as follows:

[0094]

[0095] where TimeOffset represents the time offset, i represents the serial number of the type of measurement value in the multi-path channel delay distribution measurement information, w i represents the weight of the i-th measurement value, f i (τ i ) represents the mapping function of the i-th measurement value, τ i represents the i-th measurement value, and τ0 represents the timing advance.

[0096] Furthermore, in some embodiments, can be a polynomial function of. When the value of is zero, it means that the i-th measurement value has no impact on the time offset.

[0097] After obtaining the time offset, referring to the appendix Figure 6 , in some embodiments, determining the positions of the rising window and the falling window in the OFDM symbol according to the time offset may include:

[0098] S601: Obtain a first offset segment according to the tail of the OFDM symbol and the time offset;

[0099] S602: Obtain a second offset segment according to the tail of the cyclic prefix offset of the OFDM symbol and the time offset;

[0100] S603: The rising window is adjacent to the second offset segment in the cyclic prefix offset, and the falling window is adjacent to the first offset segment.

[0101] It can be understood that in some embodiments, referring to the Figure 7 structural schematic diagram of the OFDM symbol before windowing shown in the figure, where the first offset segment is located at the tail of the OFDM symbol (which is also equivalent to Figure 7 FFT IN in it), and the length of the first offset segment matches the time offset. The second offset segment is located at the tail of the cyclic prefix offset of the OFDM symbol, and the length of the second offset segment matches the time offset. The rising window is in the cyclic prefix offset and adjacent to the second offset segment, and the falling window is adjacent to the first offset segment.

[0102] Furthermore, in some embodiments, after determining the positions of the rising window and the falling window in the OFDM symbol according to the time offset, it further includes:

[0103] Determining the window lengths of the rising window and the falling window according to the cyclic prefix offset and the time offset.

[0104] It can be understood that in some embodiments, the window lengths of the rising window and the falling window are the same, so as to facilitate subsequent windowing according to the rising window and the falling window. Specifically, referring to the Figure 8 , determining the window lengths of the rising window and the falling window according to the cyclic prefix offset and the time offset may include:

[0105] S801: Determining the difference between the cyclic prefix offset and the time offset;

[0106] S802: Determining the window lengths of the rising window and the falling window according to the difference.

[0107] It can be understood that in some embodiments, the difference between the cyclic prefix offset and the time offset can be regarded as the constraint condition for the window lengths of the rising window and the falling window. That is, in the cyclic prefix offset, except for the second offset segment, the remaining sequence positions can be used to form the rising window. Therefore, the window length of the rising window is always greater than zero and less than or equal to this difference. Furthermore, in some embodiments, referring to the Figure 9 , determining the difference between the cyclic prefix offset and the time offset may include:

[0108] S901: Mapping the time offset to obtain a sample offset;

[0109] S902: Obtaining the corresponding difference according to the cyclic prefix offset and the sample offset.

[0110] It can be understood that in some embodiments, since the time offset and the cyclic prefix offset are data in different domains, it is necessary to perform mapping processing on the time offset. Specifically, referring to the appendix Figure 10 , map the time offset to obtain a sample point offset, including:

[0111] S1001: Obtain the frame structure information corresponding to the OFDM symbol;

[0112] S1002: Use the frame structure information to map the time offset in the time domain to a sample point offset in the sample point domain.

[0113] It can be understood that in some embodiments, the frame structure information corresponding to the OFDM symbol may include sampling rate information, subcarrier spacing information, etc. According to the frame structure information, the following formula can be used to map the time offset in the time domain to a sample point offset in the sample point domain:

[0114]

[0115] where CPOffset represents the sample point offset, TimeOffset represents the time offset, and Fs represents the sampling rate information.

[0116] After obtaining the sample point offset through the above method, the corresponding difference can be quickly obtained based on the cyclic prefix offset and the sample point offset. When determining the difference, it can be calculated in two cases according to the timing of delay compensation. The specific calculation process will be elaborated below.

[0117] After determining the positions and window lengths of the rising window and the falling window, in some embodiments, windowing processing can be performed according to the rising window and the falling window to generate an OFDM symbol after interference suppression, which may include: windowing the rising window and the falling window, and superimposing the windowing result of the rising window on the windowing result of the falling window to generate an OFDM symbol after interference suppression.

[0118] Specifically, in some embodiments, referring to the appendix Figure 11 , in some embodiments, windowing the rising window and the falling window, and superimposing the windowing result of the rising window on the windowing result of the falling window to generate an OFDM symbol after interference suppression may include:

[0119] S1101: Obtain a rising window coefficient and a falling window coefficient that meet preset conditions;

[0120] S1102: Window the rising window according to the rising window coefficient, and window the falling window according to the falling window coefficient;

[0121] S1103: Superimpose the windowing result of the rising window onto the windowing result of the falling window to obtain a superimposed result;

[0122] S1104: Generate an OFDM symbol with interference suppression based on the superimposed result.

[0123] It can be understood that in some embodiments, the preset conditions include: the sum of the coefficients of the corresponding samples in the rising window and the falling window is a preset value, and both the rising window coefficient and the falling window coefficient are smooth. For example, this preset value can be 1. And since the window lengths of the rising window and the falling window are the same, if the coefficient of the nth sample in the rising window is 0.4, then the coefficient of the nth sample in the falling window is 1 - 0.4 = 0.6. Also, it should be noted that if this preset value is not 1, then a coefficient adjustment factor still needs to be multiplied by the rising window coefficient and the falling window coefficient. This coefficient adjustment factor can be equal to 1 / preset value to ensure the effectiveness of the windowing result. The process of the coefficient adjustment factor can occur before windowing to adjust the rising window coefficient and the falling window coefficient, or it can occur after windowing to adjust the windowing results of the rising window and the falling window. This is not limited in this article.

[0124] Further, in some embodiments, referring to the Figure 12a process schematic diagram of superimposing the windowing result of the rising window onto the windowing result of the falling window as shown, an OFDM symbol with interference suppression can be generated based on the obtained superimposed result. At this time, the interference in the OFDM symbol is effectively suppressed by the windowing result of the rising window. And since the windowing positions of the rising window and the falling window can change dynamically with the communication environment, the interference suppression process can adapt to the communication environment, thereby further improving the demodulation performance and the out-of-band leakage suppression ability.

[0125] Further, in some embodiments, continuing as Figure 12a shown, the OFDM symbol consists of a cyclic prefix offset and FFT IN. Among them, FFT IN is the effective time-domain symbol and is also the data that the demodulation process hopes to obtain. And FFT OUT has a time delay compared to FFT IN. It can be seen from Figure 12a that the time delay of FFT OUT compared to FFT IN is CPOffset. Specifically, in some embodiments, in order to obtain FFT IN, first, after generating an OFDM symbol with interference suppression based on the superimposed result, the cyclic prefix offset of the OFDM symbol with interference suppression needs to be removed to obtain FFT OUT, so as to facilitate obtaining FFT IN by performing time delay compensation based on FFT OUT.

[0126] Further, in some embodiments, after removing the cyclic prefix offset of the OFDM symbol after interference suppression, it is also necessary to perform a fast Fourier transform on the OFDM symbol after removing the cyclic prefix offset to obtain a corresponding spectrum signal according to the fast Fourier transform, that is, perform a fast Fourier transform according to the FFT IN in the time domain to obtain the target sequence after interference suppression, so as to use the target sequence after interference suppression for subsequent demodulation processing.

[0127] In addition, it should be noted that since a time offset is introduced during the windowing process, resulting in a time delay of the FFT OUT compared to the FFT IN, therefore, on the basis of having obtained the FFT OUT, before outputting the target sequence according to the OFDM symbol after interference suppression, it is necessary to perform time delay compensation on the current OFDM symbol according to the time offset to obtain the time delay compensated FFT OUT, that is, the FFT IN.

[0128] Specifically, in some embodiments, the timing of performing time delay compensation on the current OFDM symbol according to the time offset can occur in multiple time periods, and this is not limited herein. In some embodiments, the timing of time delay compensation can be preset to any one of the following cases 1 - case 4:

[0129] Case 1: Before windowing the rising window and the falling window to generate the OFDM symbol after interference suppression, perform time delay compensation on the current OFDM symbol according to the time offset;

[0130] Case 2: After windowing the rising window and the falling window to generate the OFDM symbol after interference suppression, and before removing the cyclic prefix offset of the OFDM symbol after interference suppression, perform time delay compensation on the current OFDM symbol according to the time offset;

[0131] Case 3: After removing the cyclic prefix offset of the OFDM symbol after interference suppression, and before performing a fast Fourier transform on the OFDM symbol after removing the cyclic prefix offset, perform time delay compensation on the current OFDM symbol according to the time offset;

[0132] Case 4: After performing a fast Fourier transform on the OFDM symbol after interference suppression, perform time delay compensation on the current OFDM symbol according to the time offset.

[0133] Among them, cases 1 - 3 are all time delay compensations in the time domain, and case 4 is a compensation in the frequency domain.

[0134] For cases 1 - 3, the compensation formula for time delay compensation in the time domain can be expressed as:

[0135]

[0136] where data is the current OFDM symbol function, n is the time-domain sample index, , l is the symbol index, is the general filtering convolution operation, filterCoefs are the convolution filter coefficients, with a total of 2×CPOffset + 1 orders, CPOffset is the sample offset, and the calculation method of the convolution filter coefficients can be , where the value range of m is [-CPOffset, CPOffset], and the calculation method of protoCoefs can be:

[0137]

[0138] The value range of the protoCoefs index is [-fftsize / 2, fftsize / 2 - 1], fftsize is the FFT size, real is the operation of taking the real part, ifftshift is the inverse zero-frequency shift, and ifft is the fast inverse Fourier transform.

[0139] For case 4, the compensation formula for compensation in the frequency domain can be expressed as:

[0140]

[0141] where, is the current OFDM symbol function, k is the frequency-domain subcarrier index, with a value range of [-fftsize / 2, fftsize / 2 - 1], fftsize is the FFT size, l is the symbol index, is the complex multiplication operation.

[0142] Also, it should be noted that when obtaining the corresponding difference according to the cyclic prefix offset and the sample offset, it is necessary to determine the configuration formula of the difference according to the preset delay compensation timing, so as to perform delay compensation according to the corresponding difference obtained from the cyclic prefix offset and the sample offset. If the delay compensation timing is case 1, at this time, in order to achieve delay compensation, it is necessary to retain the sequence length required for realizing delay compensation in the cyclic prefix offset. Therefore, the configuration formula of the difference is:

[0143] length_max = CPLen - 2×CPOffset

[0144] where length_max is the maximum length of the rising window or the falling window, CPLen is the length of the cyclic prefix offset, and CPOffset is the sample offset.

[0145] If the delay compensation timing is not case 1, when obtaining the corresponding difference according to the cyclic prefix offset and the sample offset, the configuration formula of the difference is:

[0146] length_max = CPLen - CPOffset

[0147] Among them, length_max is the maximum length of the rising window or the falling window, CPLen is the length of the cyclic prefix offset, and CPOffset is the sample offset.

[0148] In addition, to facilitate better understanding by those skilled in the art of windowing the rising window and the falling window to generate an OFDM symbol after interference suppression, this specification also provides an embodiment where the timing of delay compensation is as described in case 4 above.

[0149] Continue to refer to the appendix Figure 12a , first, the non-windowed data in the current OFDM symbol is directly passed through without windowing operations. The non-windowed data includes the first and last segments, and the sample indices of the first and last segments are respectively:

[0150]

[0151]

[0152] Among them, CPLen represents the length of the cyclic prefix offset, FFTSize represents the FFT size, length wola represents the window length of the rising window and the falling window, and CPOffset represents the sample offset corresponding to the time offset.

[0153] On this basis, the sample indices of the rising window are:

[0154]

[0155] The sample indices of the falling window are:

[0156]

[0157] Window the samples corresponding to the rising window according to the rising window coefficient, and window the samples corresponding to the rising window according to the falling window coefficient. Specifically, assuming that the window coefficient of a certain sample in the rising window or the falling window is a, and the sample value is b + cj, where j is the imaginary unit, then the windowing process is equivalent to calculating a × (b + cj) and assigning the value. The windowed sample value changes from b + cj to a × (b + cj).

[0158] After that, superimpose the windowing result of the rising window on the windowing result of the falling window to obtain a superimposed result, which is equivalent to translating the windowing result of the rising window to the same position as the falling window and then performing bitwise summation with the windowing result of the falling window. In some embodiments, the superimposed result can be represented by the following formula:

[0159]

[0160] Among them, represents the superposition result, i represents the sample index number of the superposition result, and , represents the windowing result of the rising window, k represents the sample index number of the rising window, represents the windowing result of the falling window, and k' represents the sample index number of the falling window.

[0161] Thus, according to the superposition result, the OFDM symbol after interference suppression with the sample index of is obtained.

[0162] After that, in some embodiments, when removing the cyclic prefix offset of the OFDM symbol after interference suppression, since there is a time delay of CPOffset for FFTOUT relative to FFT IN, therefore, when removing the cyclic prefix offset, in fact, the sequence other than FFTOUT is removed from the current OFDM symbol, and only the FFTOUT with the sample index of is retained. The removed sequence consists of a head sequence and a tail sequence, and the length of this sequence is the same as the length of the cyclic prefix offset. Among them, the sample index of the head sequence is , and the sample index of the tail sequence is .

[0163] After that, perform a fast Fourier transform on FFTOUT and perform time delay compensation in the frequency domain on the result of the fast Fourier transform, and the target sequence after interference suppression can be quickly obtained.

[0164] In addition, to facilitate those skilled in the art to better understand the process of windowing the rising window and the falling window to generate the OFDM symbol after interference suppression, this specification also provides a typical embodiment where the time delay compensation timing is as in the above case 1. Different from the above cases 2 - 4, in case 1, the current OFDM symbol is subjected to time delay compensation according to the time offset before windowing the rising window and the falling window to generate the OFDM symbol after interference suppression, which results in different sample indices for windowing the rising window and the falling window in case 1 compared to cases 2 - 4.

[0165] Specifically, referring to Appendix Figure 12b , after performing time delay compensation on the current OFDM symbol according to the time offset, first, the non-windowed data in the current OFDM symbol is directly passed through without windowing operation. The non-windowed data includes the head and tail segments, and the sample indices of the head and tail segments are respectively:

[0166]

[0167]

[0168] Among them, CPLen represents the length of the cyclic prefix offset, FFTSize represents the FFT size, and length wola represents the window length of the rising window and the falling window, and CPOffset represents the sample offset corresponding to the time offset.

[0169] On this basis, the sample index of the rising window is:

[0170]

[0171] The sample index of the falling window is:

[0172]

[0173] Since there will be a time delay in the FFT OUT of the OFDM symbol after interference suppression relative to the FFT IN, therefore, before windowing the rising window and the falling window, the current OFDM symbol can be compensated for time delay first.

[0174] After that, window the samples corresponding to the rising window according to the rising window coefficient, and window the samples corresponding to the falling window according to the falling window coefficient. Specifically, assuming that the window coefficient of a certain sample in the rising window or the falling window is a, and the sample value is b + cj, where j is the imaginary unit, then the windowing process is equivalent to calculating a×(b + cj) and assigning the value, and the windowed sample value changes from b + cj to a×(b + cj).

[0175] After that, superimpose the windowing result of the rising window on the windowing result of the falling window to obtain the superimposed result, which is equivalent to translating the windowing result of the rising window to the same level as the falling window and then performing bitwise summation with the windowing result of the falling window. In some embodiments, the superimposed result can be represented by the following formula:

[0176]

[0177] Among them, represents the superimposed result, i represents the sample index serial number of the superimposed result, and , represents the windowing result of the rising window, k represents the sample index serial number of the rising window, represents the windowing result of the falling window, and k' represents the sample index serial number of the falling window.

[0178] Thus, the OFDM symbol after interference suppression with the sample index is obtained according to the superimposed result.

[0179] After that, in some embodiments, when removing the cyclic prefix offset of the OFDM symbol after interference suppression, since the time delay compensation has been performed in advance before windowing the rising window and the falling window to generate the OFDM symbol after interference suppression, when removing the cyclic prefix offset, the sequence other than the FFT OUT is removed from the current OFDM symbol, and only the sample indices remaining are:

[0180] of the FFT OUT. The removed sequence consists of a head sequence and a tail sequence, and the length of this sequence is the same as the length of the cyclic prefix offset. Among them, the sample index of the head sequence is and the sample index of the tail sequence is .

[0181] After that, performing a fast Fourier transform on the OFDM symbol after removing the cyclic prefix offset can quickly obtain the target sequence after interference suppression.

[0182] It should be noted that although the operations of the method of the present invention are described in a specific order in the above embodiments and the accompanying drawings, this does not require or imply that these operations must be performed in this specific order, or that all the shown operations must be performed to achieve the desired result. Additionally or alternatively, some steps may be omitted, multiple steps may be combined into one step for execution, and / or one step may be decomposed into multiple steps for execution.

[0183] For the convenience of description, when describing the above device, it is described by dividing it into various units according to functions. Of course, when implementing this specification, the functions of each unit can be realized in the same or multiple software and / or hardware.

[0184] Corresponding to the above interference suppression method, as shown in Figure 13 some embodiments of this specification also provide a receiving end, including:

[0185] A measurement unit 1301 for measuring the channel quality;

[0186] A processor 1302 for determining the time offset according to the channel quality; determining the positions of the rising window and the falling window in the OFDM symbol according to the time offset; and performing windowing processing according to the rising window and the falling window to generate an OFDM symbol after interference suppression.

[0187] It should be noted that the computer program product described in this specification is a software product mainly implementing the method described in this specification through a computer program.

[0188] This specification embodiment also provides a computer-readable storage medium. The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the above method is implemented.

[0189] The embodiments of this specification also provide a computer-readable instruction. When a processor executes the instruction, the program therein causes the processor to execute the above method.

[0190] It should be understood that in the various embodiments of this specification, the magnitudes of the serial numbers of the above processes do not imply the order of execution. The order of execution of each process should be determined by its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of this specification.

[0191] It should also be understood that in the embodiments of this specification, the term "and / or" is merely a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B may represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in the embodiments of this specification generally represents an "or" relationship between the associated objects before and after.

[0192] Those of ordinary skill in the art can realize that the units and algorithm steps of each example described in combination with the embodiments disclosed in this specification can be implemented by electronic hardware, computer software, or a combination of the two. To clearly illustrate the interchangeability of hardware and software, the components and steps of each example have been generally described according to their functions in the above description. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the embodiments of this specification.

[0193] Those skilled in the art can clearly understand that for the convenience and brevity of description, the specific working processes of the systems, devices, and units described above can refer to the corresponding processes in the foregoing method embodiments, and will not be elaborated herein.

[0194] In the several embodiments provided by the embodiments of this specification, it should be understood that the disclosed systems, devices, and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the displayed or discussed couplings or direct couplings or communication connections to each other can be indirect couplings or communication connections through some interfaces, devices, or units, and can also be electrical, mechanical, or other forms of connection.

[0195] The unit described as a separation component may or may not be physically separated. The component shown as a unit may or may not be a physical unit, that is, it may be located in one place or distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiments of this specification.

[0196] In addition, in each of the embodiments of this specification, each functional unit may be integrated into a processing unit, may exist separately as individual physical units, or two or more units may be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of a software functional unit.

[0197] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the embodiments of this specification, in essence, or the part that contributes to the prior art, or all or part of this technical solution can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the embodiments of this specification. The aforementioned storage medium includes: USB flash drives, mobile hard disks, read-only memories (ROM, Read-Only Memory), random access memories (RAM, Random Access Memory), magnetic disks, or optical discs and other various media that can store program codes.

[0198] Specific embodiments are used in the embodiments of this specification to elaborate on the principles and implementation manners of the embodiments of this specification. The description of the above embodiments is only used to help understand the method and its core idea of the embodiments of this specification; at the same time, for those of ordinary skill in the art, according to the idea of the embodiments of this specification, there will be changes in the specific implementation manners and application scopes. In summary, the content of this specification should not be construed as a limitation to the embodiments of this specification.

Claims

1. A method for interference suppression, characterized in that The method includes: Determining a time offset according to the channel quality; Determining the positions of the rising window and the falling window in the OFDM symbol according to the time offset; Windowing the rising window and the falling window, and superimposing the windowing result of the rising window on the windowing result of the falling window to generate an OFDM symbol after interference suppression.

2. The method according to claim 1, wherein Before determining the time offset according to the channel quality, it further includes: Measuring the multi-path channel delay distribution measurement information of the time-domain received signal.

3. The method according to claim 2, characterized in that, Determining the time offset according to the channel quality includes: Analyzing the weight occupied by at least one measurement value in the multi-path channel delay distribution measurement information of the time-domain received signal; Performing weighted calculation on the multi-path channel delay distribution measurement information by using the weight to obtain the time offset.

4. The method according to claim 1, characterized in that, Determining the positions of the rising window and the falling window in the OFDM symbol according to the time offset includes: Obtaining a first offset segment according to the tail of the OFDM symbol and the time offset; Obtaining a second offset segment according to the tail of the cyclic prefix offset of the OFDM symbol and the time offset; The rising window is adjacent to the second offset segment in the cyclic prefix offset, and the falling window is adjacent to the first offset segment.

5. The method according to claim 4, wherein After determining the positions of the rising window and the falling window in the OFDM symbol according to the time offset, it further includes: Determining the window lengths of the rising window and the falling window according to the cyclic prefix offset and the time offset.

6. The method according to claim 5, characterized in that, Determining the window lengths of the rising window and the falling window according to the cyclic prefix offset and the time offset further includes: Determining the difference between the cyclic prefix offset and the time offset; Determining the window lengths of the rising window and the falling window according to the difference.

7. The method according to claim 6, wherein Determining the difference between the cyclic prefix offset and the time offset includes: Mapping the time offset to obtain a sample offset; Obtaining the corresponding difference according to the cyclic prefix offset and the sample offset.

8. The method according to claim 7, wherein Mapping the time offset to obtain a sample offset includes: Obtaining the frame structure information corresponding to the OFDM symbol; Using the frame structure information to map the time offset in the time domain to the sample offset in the sample domain.

9. The method according to claim 1, characterized in that, Windowing the rising window and the falling window, and superimposing the windowing result of the rising window on the windowing result of the falling window to generate an OFDM symbol after interference suppression includes: Obtaining a rising window coefficient and a falling window coefficient that meet preset conditions; Windowing the rising window according to the rising window coefficient, and windowing the falling window according to the falling window coefficient; Superimposing the windowing result of the rising window on the windowing result of the falling window to obtain a superimposing result; Generating an OFDM symbol after interference suppression according to the superimposing result.

10. The method according to claim 9, wherein The preset conditions include that the sum of the coefficients of the corresponding samples in the rising window and the falling window is a preset value.

11. The method according to claim 9, wherein After generating the OFDM symbol after interference suppression according to the superimposing result, it further includes: Removing the cyclic prefix offset of the OFDM symbol after interference suppression.

12. The method according to claim 11, wherein After removing the cyclic prefix offset of the OFDM symbol after interference suppression, it further includes: Performing fast Fourier transform on the OFDM symbol after removing the cyclic prefix offset.

13. The method according to claim 9, characterized in that After generating an OFDM symbol with interference suppression based on the superimposed result, it further includes: Generating a target sequence with interference suppression based on the OFDM symbol with interference suppression.

14. The method according to claim 13, wherein Before outputting the target sequence based on the OFDM symbol with interference suppression, it further includes: Performing time delay compensation on the current OFDM symbol according to the time offset.

15. A receiving end, characterized in that, It includes A measurement unit for measuring the channel quality; A processor for determining the time offset according to the channel quality; determining the positions of the rising window and the falling window in the OFDM symbol according to the time offset; and performing windowing processing according to the rising window and the falling window to generate an OFDM symbol with interference suppression.

16. A computer device, comprising a memory, a processor, and a computer program stored on the memory, characterized in that, When the computer program is run by the processor, it executes the instructions of the method according to any one of claims 1-14.

17. A computer storage medium having a computer program stored thereon, characterized in that, When the computer program is run by the processor of the computer device, it executes the instructions of the method according to any one of claims 1-14.

18. A computer program product, characterized in that, The computer program product includes a computer program, and when the computer program is run by the processor, it executes the instructions of the method according to any one of claims 1-14.

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