Precoding method, antenna communication system and storage device based on channel prediction

Abstract

The application discloses a precoding method based on channel prediction, an antenna communication system and a storage medium. The precoding method based on channel prediction is applied to the antenna communication system, and the method comprises the following steps: obtaining first channel state information at a previous moment according to a channel estimation algorithm; obtaining second channel state information at a current moment by performing channel prediction according to the first channel state information at the previous moment; sampling the second channel state information; and performing precoding according to the second channel state information after sampling. Channel state information is obtained by using channel prediction, instead of traditional channel estimation, so that the performance of precoding technology in a large-scale antenna communication system is improved.

Description

Technical Field

[0001] The present invention relates to the automotive field, and in particular to a precoding method based on channel prediction, an antenna communication system, and a storage medium. Background Art

[0002] For communication systems, in order to improve transmission efficiency and reduce power loss, when the channel state information is known, the transmitted signal is usually pre-processed at the transmitting end to facilitate signal detection by the receiver, that is, precoding.

[0003] Precoding techniques for multi-antenna arrays typically fall into two categories: linear and nonlinear. Common nonlinear precoding implementations include dirty paper coding, while linear precoding solutions include zero forcing and MMSE (minimum mean square error) precoding. Generally speaking, compared to nonlinear precoding solutions, linear precoding is simpler to implement and can result in suboptimal system performance and capacity. However, for millimeter-wave massive antenna array systems, research has shown that simple linear precoding can achieve performance that matches or approaches that of nonlinear precoding.

[0004] In large-scale antenna array technology, the time division duplex (TDD) mode is usually used for channel estimation. That is, a training sequence is transmitted on the uplink channel, channel estimation is performed at the base station, and the estimated channel state information is then used for downlink precoding and coherent signal detection. However, because millimeter wave communication uses ultra-high frequency spectrum resources, in a mobile communication environment, the level fluctuation speed of the received signal will far exceed the signal level fluctuation speed of the currently widely used low-frequency communication system. That is, the channel state information will change rapidly, which will cause the channel coherence time of the millimeter wave communication system to become extremely short. At this time, the channel state information obtained by the uplink channel estimation in the large-scale antenna array system will quickly become outdated and cannot be directly used for downlink transmission precoding. Therefore, it is necessary to provide a channel prediction precoding technology that can overcome the problem of outdated channel information obtained by channel estimation. Summary of the Invention

[0005] The main purpose of the present invention is to provide a precoding method based on channel prediction, which can significantly improve the precoding performance.

[0006] To achieve the above object, the present invention provides a precoding method based on channel prediction, which is applied to an antenna communication system. The method includes:

[0007] Obtaining first channel state information at a previous moment according to a channel estimation algorithm;

[0008] Performing channel prediction based on the first channel state information to obtain second channel state information at a current moment;

[0009] sampling the second channel state information;

[0010] Precoding is performed according to the sampled second channel state information.

[0011] Furthermore, the method further comprises:

[0012] According to the precoding, a precoding column vector is obtained,

[0013] generating the signal data according to the precoding column vector;

[0014] The signal data is sent to a receiving end.

[0015] Furthermore, obtaining a precoding column vector according to the precoding further includes:

[0016] According to the first formula, the precoding column vector is obtained

[0017] The first formula is:

[0018]

[0019] Among them, "*" is the conjugate operation, is the channel prediction value of the u-th receiving antenna, k-th subcarrier, and i-th time of the base station of the antenna communication system,

[0020] is the second signal state information vector, and i represents the i-th moment of the second channel state information.

[0021] Furthermore, before sending the signal data to the receiving end, the method further includes:

[0022] The signal data is weighted according to a second formula, where the second formula is:

[0023] x[i,k]=d[i,k]s[i,k],·····(2)

[0024] Where d[i,k] is an M×1 precoding column vector, M is the number of base station antennas, and s[i,k] is the actual data sent by the base station to the user.

[0025] Furthermore, sending the signal data to the receiving end includes: expressing the signal data according to the third formula, and the third formula is:

[0026] y[i,k]=h T [i,k]x[i,k]+z[i,k]·····(3)

[0027] Where y[i,k] is the signal data received by the receiver, "T" is the transpose operator, h[i,k] is the column vector of the second channel state information of the base station's antenna array, x[i,k] is the column vector of the data sent by the corresponding antenna array, and z[i,k] is the channel noise corresponding to the channel.

[0028] Furthermore, performing channel prediction to obtain second channel state information specifically includes:

[0029] Channel prediction is performed on the first channel state information according to an autoregressive model to obtain second channel state information.

[0030] Furthermore, the performing channel prediction to obtain the second channel state information, the method further includes:

[0031] The second channel state information is sampled according to a channel interpolation method.

[0032] The present invention also provides an antenna communication system, which includes a memory and a processor, wherein the memory stores a precoding program based on channel prediction that can be run on the processor, and when the precoding program based on channel prediction is executed by the processor, the precoding method based on channel prediction described above is implemented.

[0033] The present invention also provides a storage medium storing a computer program, wherein the computer program, when processed by a processor, implements any of the above-mentioned precoding methods based on channel prediction.

[0034] The beneficial effect of the present invention is that channel state information is obtained by using channel prediction instead of traditional channel estimation to obtain channel state information, thereby improving the performance of precoding technology in large-scale antenna communication systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 A schematic structural diagram of the antenna communication system provided by the present invention;

[0036] Figure 2 A schematic diagram of the flow of the precoding method based on channel prediction provided by the present invention;

[0037] Figure 3 A schematic flow chart of another embodiment of the precoding method based on channel prediction provided by the present invention;

[0038] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0040] The terms "first," "second," "third," "fourth," and the like (if any) in the specification and claims of this application and in the accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a particular order or sequential sequence. It should be understood that the terms used in this manner are interchangeable where appropriate so that the embodiments described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "including" and "having," and any variations thereof, are intended to cover non-exclusive inclusions, e.g., a process, method, system, product, or apparatus comprising a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0041] It should be noted that the descriptions of "first", "second", etc. in the present invention are for descriptive purposes only and should not be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions between the various embodiments can be combined with each other, but this must be based on the fact that they can be implemented by ordinary technicians in this field. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0042] The following is an introduction to some of the concepts designed in the embodiments of this application.

[0043] Please see Figure 1 The present invention also provides an antenna communication system, which includes a memory 12 and a processor 11. The memory 12 stores a precoding method program based on channel prediction that can be run on the processor 11. When the precoding method program based on channel prediction is executed by the processor 11, a precoding method based on channel prediction is implemented.

[0044] Antenna communication systems typically use a time division duplex (TDD) mode for channel estimation. Specifically, a training sequence is transmitted on the uplink channel, channel estimation is performed at the base station, and the estimated channel state information is then used for downlink precoding and related signal detection. In this embodiment, first channel state information (i.e., frequency-array domain channel state information) is obtained based on channel estimation. Channel prediction techniques are then used to predict second channel state information based on the first channel state information, and precoding is then performed based on the second channel state information.

[0045] Please see Figure 2 The present invention provides a precoding method based on channel prediction for an antenna communication system, and the specific method is as follows:

[0046] Step S10: Obtaining first channel state information at a previous moment according to a channel estimation algorithm;

[0047] Specifically, the traditional channel estimation algorithm can be used to obtain the frequency-array domain channel state information Where u represents the uth base station antenna, n represents the nth time, and k represents the kth OFDM (Orthogonal Frequency Division Multiplexing) subcarrier. The first channel state information at the nth time is obtained to prepare for the second channel state information obtained by channel prediction at the n+1th time.

[0048] Step S11: performing channel prediction based on the first channel state information to obtain the second channel state information at the current moment;

[0049] Specifically, based on the symmetry between the uplink and downlink channels in the TDD mode, the first channel state information of the uplink channel can be used to predict and replace the second channel state information required for downlink channel precoding (downlink information transmission time). The prediction algorithm can be a channel prediction method based on an AR (autoregressive) model, etc. It is the channel prediction value of the u-th receiving antenna, the k-th subcarrier, and the n+1-th time in the downlink channel array-frequency domain. The channel prediction value can be obtained in advance by predicting the first channel state information value at the n-th time.

[0050] Step S12: sampling the second channel state information;

[0051] Specifically, before precoding, because the sampling interval for channel prediction is much longer than the sampling interval for data transmission, a suitable channel interpolation method is required to obtain the second channel state information for each data transmission moment and provide it to the module generating the precoding. It is important to note that when selecting a suitable channel interpolation method, the rapid time-varying nature of large-scale antenna communication systems should be taken into account. In this embodiment, the channel interpolation methods used include third-order spline interpolation or interpolation based on the raised cosine function.

[0052] Step S13: performing precoding according to the sampled second channel state information;

[0053] Based on the channel state information obtained at the time of data transmission, the system's transmission data can be precoded. In a large-scale antenna communication system, simple linear precoding or nonlinear precoding can usually be used. The present invention is suitable for multi-user or single-user systems.

[0054] In the above embodiment, channel prediction is used to obtain channel state information instead of traditional channel estimation to improve the performance of precoding technology in a massive antenna communication system.

[0055] Please see Figure 3 In the precoding method based on channel prediction, after precoding, the transmitted data is processed according to the precoding, specifically including:

[0056] Step S20: According to the precoding, obtain a precoding column vector,

[0057] Step S21: generating the signal data according to the precoding column vector;

[0058] Step S22: Send the signal data to the receiving end.

[0059] Specifically, the precoding column vector is obtained according to a first formula, where the first formula is:

[0060]

[0061] Among them, "*" is the conjugate operation, is the channel prediction value of the u-th receiving antenna, k-th subcarrier, and i-th time of the base station of the antenna communication system,

[0062] is the second signal state information vector, and i represents the i-th moment of the second channel state information.

[0063] Specifically, before sending the signal data to the receiving end, the signal data is weighted according to a second formula to achieve coherent reception at the user end. The second formula is:

[0064] x[i,k]=d[i,k]s[i,k],·····(2)

[0065] Where d[i,k] is an M×1 precoding column vector, M is the number of base station antennas, and s[i,k] is the actual data sent by the base station to the user.

[0066] In step S22, sending the signal data to the receiving end includes: expressing the signal data according to the third formula, where the third formula is:

[0067] y[i,k]=h T [i,k]x[i,k]+z[i,k]·····(3)

[0068] Where y[I,k] is the signal data received by the receiving end, "T" is the transpose operator, h[i,k] is the column vector of the second channel state information of the base station's antenna array, x[i,k] is the column vector of the data sent by the corresponding antenna array, and z[i,k] is the channel noise corresponding to the channel.

[0069] Existing precoding techniques primarily rely on channel state information (CSI) obtained through channel estimation. However, for large-scale antenna communication systems, this CSI can become outdated, impacting system performance. This embodiment utilizes channel prediction to obtain CSI for precoding, overcoming this issue and significantly improving precoding performance.

[0070] In this embodiment, the memory 12 and the storage 12 include at least one type of readable storage medium, including flash memory, a hard disk, a multimedia card, a card-type memory (such as an SD or DX memory 12), a magnetic memory, a magnetic disk, an optical disk, etc. In some embodiments, the memory 12 can be an internal storage unit of the antenna communication system, such as a hard disk of the antenna communication system. In other embodiments, the memory 12 can also be an external storage device of the antenna communication system, such as a plug-in hard disk equipped on the antenna communication system, a smart memory card (SMC), a secure digital (SD) card, a flash memory card, etc. Furthermore, the memory 12 can include both an internal storage unit of the antenna communication system and an external storage device. The memory 12 can be used not only to store application software installed in the antenna communication system and various types of data, such as the antenna communication system's code, but also to temporarily store data that has been output or is about to be output.

[0071] In some embodiments, the processor 11 may be a central processing unit (CPU), a controller, a microcontroller, a microprocessor, or other data processing chip, configured to execute program codes stored in a memory or process data, such as a precoding program based on channel prediction.

[0072] The present application also provides a storage medium that can store a program that, when executed, can run some or all of the steps of the method described in the present application. In a specific implementation, the computer storage medium of the present application includes: RAM, ROM, EEPROM, flash memory, CD-ROM, DVD or other optical storage, magnetic tape, disk or other magnetic storage, or any other medium that can be used to store the required information and can be accessed by a computer device.

[0073] It should be noted that the serial numbers of the above-mentioned embodiments of the present invention are for description only and do not represent the advantages and disadvantages of the embodiments. In addition, the terms "including", "comprising" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, device, article or method including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, device, article or method. In the absence of further restrictions, an element defined by the sentence "including a..." does not exclude the presence of other identical elements in the process, device, article or method including the element.

[0074] Those skilled in the art will 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 aforementioned method embodiments and will not be repeated here.

[0075] The above are only preferred embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention description and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A precoding method based on channel prediction, applied to an antenna communication system, characterized in that: The method comprises: Obtaining first channel state information at a previous moment according to a channel estimation algorithm; performing channel prediction based on the first channel state information at the previous moment to obtain second channel state information at the current moment; based on the symmetry between uplink and downlink channels in the TDD mode, using the first channel state information of the uplink channel to predict and replace second channel state information required for downlink channel precoding, using a prediction algorithm based on an AR model; sampling the second channel state information according to a channel interpolation method; Precoding is performed according to the sampled second channel state information; specifically, precoding is performed on the system's transmission data based on the acquired channel state information at the data transmission time; The method further comprises: According to the precoding, a precoding column vector is obtained, generating signal data according to the pre-coded column vector; Sending the signal data to a receiving end; The obtaining of a precoding column vector according to the precoding further includes: According to the first formula, the precoding column vector is obtained The first formula is: Among them, "*" is the conjugate operation, is the second channel state information of the u-th receiving antenna, the k-th subcarrier, and the i-th time of the base station of the antenna communication system, where k represents the k-th OFDM subcarrier; is the second channel state information vector, i represents the i-th moment of the second channel state information; Before sending the signal data to the receiving end, the method further includes: The signal data is weighted according to a second formula, where the second formula is: x[i,k]=d[i,k]s[i,k]......(2) Where d[i,k] is the M×1 precoding column vector, M is the number of base station antennas, and s[i,k] is the actual data sent by the base station to the user; The sending of the signal data to the receiving end includes: expressing the signal data according to the third formula, where the third formula is: y[i,k]=h T [i,k]x[i,k]+z[i,k]......(3) Where y[i,k] is the signal data received by the receiver, "T" is the transpose operator, h[i,k] is the column vector of the second channel state information of the base station's antenna array, x[i,k] is the column vector of the data sent by the corresponding antenna array, and z[i,k] is the channel noise corresponding to the channel.

2. An antenna communication system, characterized in that: The antenna communication system includes a memory and a processor, wherein the memory stores a precoding program based on channel prediction that can be run on the processor, and when the precoding program based on channel prediction is executed by the processor, the precoding method based on channel prediction as described in claim 1 is implemented.

3. A storage medium storing a computer program, characterized in that: When the computer program is processed by a processor, the precoding method based on channel prediction according to claim 1 is implemented.

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