RU2632417C2 - Method, system and device for precoding - Google Patents

Abstract

FIELD: radio engineering, communication.

SUBSTANCE: precoding method includes: performing pre-processing of precoding for a signal to be transmitted, wherein pre-processing causes an increase in the signal power to be transmitted; selecting power limitation algorithm according to the selection rule; performing power limiting operation for pre-processed signal according to the selected power limiting algorithm; and generating a pre-coded signal according to the limited power signal. An embodiment of present invention further discloses a transmitting device, a receiver and a precoding system. In present invention, the adverse effect exerted by power limit operation on signaling can be reduced as much as possible at a time when the transmission power is limited by using power limiting operation.

EFFECT: improving the quality of communication by suppressing successive interference between signal streams.

17 cl, 8 dwg

Description

FIELD OF THE INVENTION

[0001] The present invention relates to the field of wireless communication technology and, in particular, to a method, apparatus and precoding system.

BACKGROUND

[0002] MIMO technology (with many inputs and many outputs, with many inputs and many outputs) can increase the throughput of a wireless communication system in a state in which transmission power is not increased. MIMO technology is extensively used in systems such as LTE (long-term development standard, long-term development standard) and WiMAX.

[0003] Pre-coding is an important branch of MIMO technology and, in essence, can be considered as a technology of preliminary frequency correction of the channel. On the transmitter side, the data is pre-processed according to the channel information, so that a better signal to noise ratio can be obtained after the signal passes through the channel, and further, better performance is obtained on the receiver side. General precoding algorithms include a linear type and a non-linear type. Linear precoding means that precoding processing can be implemented through a linear operation, and, in general, the implementation is simple. Non-linear precoding means that there is a non-linear operation in the precoding process, and its implementation is complex, but, in general, better performance can be obtained.

[0004] In some non-linear precoding algorithms, for example, THP (Tomlinson-Harashima precoding, Tomlinson-Harashima precoding) and VP (vector perturbation, vector perturbation), some processing steps may cause an increase in the power of the signal to be transmitted, and therefore, a power limiting operation must be performed. In all currently used nonlinear precoding algorithms, the modulo operation is used to perform power limitation. However, in actual use, due to factors such as estimation error and external interference, the modulo operation generally causes performance loss in signal transmission.

[0005] ZF-THP (Tomlinson-Harashima precoding based on zero-force, Tomlinson-Harashima precoding based on zero-forcing) based on QR decomposition is used as an example for description. FIG. 1 is a schematic diagram of a ZF-THP-based precoding method on a transmitter side in the prior art. FIG. 2 is a schematic diagram of a precoding method on the receiver side corresponding to FIG. 1. The modulo operation is equivalent to summing the modulo offset with the signal, so that the amplitude of the signal after the modulo operation does not exceed the target upper limit. However, this modulo bias inevitably causes interference to the signal. Even if the modulo recovery operation, which is completely identical to the modulo operation, is performed for the received signal on the receiver side, the modulo operation can still not be completely eliminated due to imperfect feedback and channel estimation and the influence of noise and interference, and, therefore, loss of performance in signaling is caused.

SUMMARY OF THE INVENTION

[0006] Embodiments of the present invention provide a method, system, and precoding apparatus so that the adverse effect exerted by the power limiting operation on signal transmission can be reduced as much as possible while the power is limited.

[0007] An embodiment of the present invention provides a precoding method including:

- performing pre-processing of pre-coding for the signal to be transmitted, wherein pre-processing causes an increase in the power of the signal to be transmitted;

- selection of a power limitation algorithm according to a selection rule;

- performing a power limiting operation for a pre-processed signal according to a selected power limiting algorithm; and

- the formation of a pre-encoded signal according to the signal with limited power.

[0008] An embodiment of the present invention further provides a precoding method, including:

- receiving information modulo transmitted by a transmitting device; and

- determining, according to the modulo information, whether or not the transmitting device performs a modulo operation for the signal after preprocessing the precoding, and when determining "Yes", the modulo recovery operation is performed for the received signal.

[0009] An embodiment of the present invention further provides a transmission device including:

- a pre-coding pre-processing module, configured to pre-coding pre-processing for the signal to be transmitted, the pre-processing causing an increase in the power of the signal to be transmitted;

- a module for selecting a power limiting algorithm, configured to select a power limiting algorithm according to a selection rule;

a power limiting module configured to perform a power limiting operation for a pre-processed signal according to a selected power limiting algorithm; and

- a module for generating precoded signals, configured to generate a precoded signal according to a signal with limited power.

[0010] An embodiment of the present invention further provides a receiving device including:

- module information receiving module, configured to receive module information transmitted by a transmitting device;

- a module for determining the execution of the operation modulo, configured to determine, according to the information modulo, then, whether or not the transmitting device performs the operation modulo the signal after pre-processing the precoding; and

- a module for performing a module recovery operation, configured to perform a module recovery operation for a received signal if the result of determining the module for determining the module operation is “Yes”.

[0011] An embodiment of the present invention further provides a precoding system including a transmitting device and a receiving device, the transmitting device including:

- a pre-coding pre-processing module, configured to pre-coding pre-processing for the signal to be transmitted, the pre-processing causing an increase in the power of the signal to be transmitted;

- a module for selecting a power limiting algorithm, configured to select a power limiting algorithm according to a selection rule;

a power limiting module configured to perform a power limiting operation for a pre-processed signal according to a selected power limiting algorithm; and

- a module for generating precoded signals, configured to generate a precoded signal according to a signal with limited power.

[0012] The implementation of embodiments of the present invention has the following advantages. Different power limiting algorithms are adaptively selected in various cases. Not only is the transmission power controlled in such a way that it corresponds to the limitation of the hardware state, but also the adverse effect exerted by the power limiting operation on signal transmission is minimized as much as possible.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly describe the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings required to describe the embodiments or the prior art are briefly presented below. Obviously, the accompanying drawings in the description below show only some embodiments of the present invention, and those skilled in the art can still derive other drawings from these attached drawings without creative efforts.

[0014] FIG. 1 is a schematic diagram of a method for precoding on the side of a transmitter in the prior art;

[0015] FIG. 2 is a schematic diagram of a prior art encoding method of a receiving device in the prior art;

[0016] FIG. 3 is a flowchart of a first embodiment of a precoding method on the side of a transmitter of the present invention;

[0017] FIG. 4 is a flowchart of a second embodiment of a precoding method on the side of a transmitter of the present invention;

[0018] FIG. 5 is a flowchart of a first embodiment of a precoding method on the receiver side according to the present invention;

[0019] FIG. 6 is a schematic structural diagram of a first embodiment of a transmission device according to the present invention;

[0020] FIG. 7 is a schematic structural diagram of a second embodiment of a transmitting device according to the present invention;

[0021] FIG. 8 is a schematic structural diagram of a first embodiment of a receiving device according to the present invention.

DETAILED DESCRIPTION OF EMBODIMENTS

[0022] The technical solutions in the embodiments of the present invention are described below and fully described with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, but not all, embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts should fall within the protection scope of the present invention.

[0023] Referring to FIG. 3, FIG. 3 is a flowchart of a first embodiment of a precoding method on the side of a transmitter of the present invention. The method includes:

[0024] Step S300. Performing pre-processing of the precoding for the signal to be transmitted, wherein the preprocessing causes an increase in the power of the signal to be transmitted. For example, pre-processing may include all processing steps that can increase the signal power in a pre-coding algorithm, for example, processing to suppress sequential interference between signal streams.

[0025] Step S301. The choice of power limitation algorithm according to the selection rule. For example, a selection rule includes: selecting a power limitation algorithm with minimal performance loss, wherein the performance loss is the difference between the communication quality after the power limiting operation is performed and the communication quality when the power limiting operation is not performed. The selection rule may further include: selecting a power limitation algorithm that can generate minimal noise. Several power limiting algorithms can be pre-stored, and then the most suitable one is selected in a particular case according to the selection rule.

[0026] Step S302. Performing a power limiting operation for a pre-processed signal according to a selected power limiting algorithm.

[0027] Step S303. Generating a precoded signal according to a limited power signal. In particular, some post-processing of precoding may be performed for a signal with limited power. Post-processing may include the remaining processing steps after pre-processing and power limitation processing in the precoding algorithm are completed, for example, processing for converting a signal stream to an antenna.

[0028] In the precoding method provided by an embodiment of the present invention, various power limiting algorithms are adaptively selected in various cases. Not only is the transmission power controlled in such a way that it corresponds to the limitation of the hardware state, but also the adverse effect exerted by the power limiting operation on signal transmission is minimized as much as possible.

[0029] Referring to FIG. 4, FIG. 4 is a flowchart of a second embodiment of a precoding method on the side of a transmitter of the present invention. The method includes:

, где u_k указывает предварительно обработанный сигнал, a_k указывает сигнал, который должен передаваться, b_kl указывает элемент в k-й строке и l-м столбце B, и v_l указывает сигнал с ограниченной мощностью. Как можно видеть из вышеприведенного процесса обработки, вследствие влияния члена

, расположенного в правой части формулы, мощность u_k выше мощности a_k, и, следовательно, необходимо выполнять операцию ограничения мощности для сигнала после обработки предварительного кодирования таким образом, ограничивать мощность передачи.[0030] Step S400. Performing pre-processing of the precoding for the signal to be transmitted, wherein the preprocessing causes an increase in the power of the signal to be transmitted. Using ZF-THP as an example and assuming that the numbers of antennas on the side of the receiving device and the side of the transmitting device are symmetrical and are K, and that the signals to be transmitted are a ₁ , a ₂ ..., a _K , processing pre-coding includes: obtaining a channel matrix H according to the feedback of the receiving device or obtaining an approximate channel matrix H of the downlink according to the estimation of the pilot channel of the uplink and decomposition H to obtain ^H = LQ H, where L is a lower triangular matrix with size K × K, Q is a unitary matrix with dimensions K × K, and the expansion can be realized through the QR-decomposition ^H H, where ^H H indicates conjugate transpose of H; then obtaining the matrix B according to B = GL, where G is a diagonal matrix including the inverse values of the diagonal elements of L, and therefore B is a lower triangular matrix whose diagonal elements are 1; and calculating pre-processed signals according to

where u _k indicates a pre-processed signal, a _k indicates a signal to be transmitted, b _kl indicates an element in the kth row and lth column B, and v _l indicates a signal with limited power. As can be seen from the above processing process, due to the influence of the member

located on the right side of the formula, the power u _{k is} higher than the power a _k , and therefore, it is necessary to perform the power limiting operation for the signal after precoding processing in this way, to limit the transmit power.

[0031] Step S401. Determination, according to the selection rule, of whether or not to choose an algorithm with an operation by modulo from an algorithm with an operation by modulo and an algorithm for limiting power without an operation by modulo. The modulo operation algorithm includes: determining the modulo offset and using the sum of the modulo offset and the pre-processed signal as a signal after the modulo operation, the signal amplitude after the modulo operation not exceeding a predetermined amplitude threshold value. A power limiting algorithm without a modulo operation may include a linear power limiting algorithm or any nonlinear power limiting algorithm, with the exception of a modulo operation algorithm. When using the linear power limitation algorithm as an example, the algorithm includes: determining the power limiting coefficient and multiplying the power limiting coefficient by a pre-processed signal or multiplying the power limiting coefficient by the signal to be transmitted, which is included in the pre-processed signal, and using the signal after calculating the multiplication as a signal after the linear power limitation operation, the power of the linear ogre operation power reduction does not exceed a preset threshold power value. Although the modulo operation and the linear power limiting operation can well limit the power, and compared to skipping, the power limiting operations have performance losses, the performance losses caused by them vary depending on different cases. For example, when the channel condition and / or channel quality is poor, the performance losses caused by the linear power limiting operation are very large; or when the channel condition and / or channel quality is relatively good, the linear performance of the power limiting operation performance loss may be less than the modular operation performance loss. Therefore, the selection rule may include: selecting one of the algorithm with a modulo operation and the linear power limitation algorithm according to the current channel state and / or channel quality. For example, when the measurement value of one or more indicators of the current channel status and / or channel quality exceeds a predetermined threshold value, it is considered that the loss of performance of the modulo operation is less than the loss of performance of the linear power limitation operation, and therefore, the algorithm with the modulo operation is selected; or when the measurement value of one or more indicators of the current channel state and / or channel quality is less than a predetermined threshold value, it is considered that the modulo operation performance loss exceeds the performance loss of the linear power limitation operation, and therefore, the linear power limitation algorithm is selected. Indicators of channel status and / or channel quality include a signal-to-noise ratio, correlation between antennas, channel correlation between users, and the like. In order to provide better communication quality, the choice of a power limitation algorithm can be based on a more complex coefficient. For example, step S401 may include: determining, according to the performance loss of the algorithm with the modulo operation and the performance losses of the linear power limitation algorithm, whether or not to select the algorithm with the modulo operation. The following uses the modulo operation algorithm and the linear power limitation algorithm as examples to describe in detail how to evaluate performance losses.

[0032] Preferably, in step S401, the modulo-operation algorithm performance loss is estimated according to the current channel state, channel quality and / or current modulation and coding scheme. In particular, the performance losses that can be caused by using the modulo operation in this case can be estimated according to the current channel state and / or channel quality and the previously saved modulo operation performance losses in various channel conditions and / or channel quality, and / or performance losses that can be caused by using the modulo operation in this case can be estimated according to the current modulation and coding scheme and previously stored The resulting loss of performance of modulo operations in various modulation and coding schemes. The performance loss of an algorithm with a modulo operation in different channel conditions and / or channel quality or in various modulation and coding schemes can be determined using a method such as precalculation, preliminary modeling, or preliminary measurement.

, по сравнению с мощностью полезного сигнала до того, как выполняется нормализация, потери мощности полезного сигнала после операции ограничения мощности (выражаемые в форме дБ) составляют

. В частности, потери производительности операции линейного ограничения мощности могут оцениваться согласно потерям мощности для мощности полезного сигнала после операции линейного ограничения мощности, относительно мощности полезного сигнала перед операцией линейного ограничения мощности и соответствия между предварительно сохраненными потерями мощности и потерями производительности, причем соответствие между потерями мощности и потерями производительности может получаться посредством использования такого способа, как предварительное моделирование, предварительное вычисление или предварительное измерение. Помимо этого, потери мощности для мощности полезного сигнала после операции линейного ограничения мощности, относительно мощности полезного сигнала перед операцией линейного ограничения мощности, также могут быть непосредственно использованы в качестве потерь производительности операции линейного ограничения мощности.[0033] Preferably, in step S401, the performance losses of the linear power limiting algorithm are estimated according to the power losses for the useful signal power after the linear power limiting operation, relative to the useful signal power before the linear power limiting operation. For example, provided that the power limiting coefficient calculated according to the above method is

, compared with the power of the useful signal before normalization is performed, the power loss of the useful signal after the power limiting operation (expressed in dB form) is

. In particular, the performance loss of the linear power limiting operation can be estimated according to the power loss for the useful signal power after the linear power limiting operation, relative to the useful signal power before the linear power limiting operation and the correspondence between the previously saved power loss and the performance loss, the correspondence between the power loss and performance losses can be obtained by using a method such as In-line modeling, pre-calculation or pre-measurement. In addition, the power loss for the useful signal power after the linear power limiting operation, relative to the useful signal power before the linear power limiting operation, can also be directly used as the performance loss of the linear power limiting operation.

, где

является смещением по модулю. Посредством выполнения операции по модулю, действительная часть и мнимая часть

ограничены рамками диапазона, и, следовательно, его мощность также ограничена рамками целевого диапазона.[0034] If the determination result in step S401 is “Yes”, step S402 is performed. Step S402 Performing a modulo operation for the signal after preprocessing the precoding, wherein the modulo operation includes summing the offset modulo the signal after the preprocessing. Also, when using ZF-THP as an example for description, the signal after the operation modulo is

where

is the offset modulo. By performing the modulo operation, the real part and the imaginary part

limited by the range, and therefore its power is also limited by the range of the target range.

ограничения мощности, так что мощность сигнала

после операции линейного ограничения мощности не превышает предварительно установленное пороговое значение мощности.[0035] If the determination result in step S401 is “No”, step S403 is performed. Step S403 Performing a power limiting operation without a modulo operation, for example, a linear power limiting operation, for a signal after preprocessing a precoding. When using the linear power limiting operation used in the ZF-THP algorithm as an example, step S403 specifically includes: determining a coefficient

power limits so that the signal power

after the operation of linear power limitation does not exceed a preset threshold power value.

, где

и

.[0036] Step S404. Performing post-processing precoding for a signal with limited power to generate a pre-encoded signal. Also, when using ZF-THP as an example to describe the precoding post-processing, post-processing comprises: multiplying the signal v _{k (k} = 1, 2, ..., K) after the modulo operation or the operation of the linear power limit by the matrix Q, obtained by pre-processing, in order to obtain a pre-encoded signal x _k (k = 1, 2 ..., K), namely,

where

and

.

[0037] Step S405. The transmission, to the receiver, of the modulo information, which is used to indicate whether or not the transmitter is performing the modulo operation for the signal after preprocessing. The modulo information can be used by the receiver to determine, according to the modulo information, whether or not to perform the modulo recovery operation for the received signal. The modulo recovery operation performed by the receiver is identical to the modulo operation performed by the transmitter. Since the modulo operation can interfere with the desired signal, in order to reduce the modulo operation performance loss, it is necessary to perform, on the receiver side, a modulo recovery operation that is completely identical to the modulo recovery operation on the side of the transmitting recovery unit. However, if linear power limitation is used in the power limitation algorithm on the transmitter side, it is not necessary to perform a module recovery operation for the received signal on the receiver side to recover. Therefore, by transmitting, to the receiver, modulo information to indicate whether or not the modulo operation for the signal is performed after preprocessing the precoding, the performance loss in signaling can be reduced more appropriately, losses caused by performing an optional recovery operation are eliminated modulo for the receiver side, and communication quality is improved.

, чтобы получать матрицу Q и матрицу B, где

,

является мощностью шума приемного устройства, и

является мощностью сигнала v с ограниченной мощностью;

указывает псевдообратную матрицу относительно матрицы H, и если количество строк H превышает или равно количеству столбцов,

, либо если количество столбцов H превышает количество строк,

. Другие этапы этого алгоритма являются аналогичными этапам согласно ZF-THP. По сравнению с ZF-THP, этот алгоритм рассматривает шум и помехи на стороне приемного устройства. Для информации по модулю, канал может отдельно заниматься для передачи, или информация по модулю может передаваться вместе с другими необходимыми сигналами связи. Если информация по модулю передается вместе с другими необходимыми сигналами связи, может быть необязательным занимать дополнительный ресурс канала. Далее используется LTE-система связи в качестве примера для того, чтобы кратко описывать способ для передачи информации по модулю.[0038] Although this embodiment is described by using ZF-THP as an example, the present invention is not limited to the ZF-THP precoding algorithm, and may be applicable to any precoding algorithm that may cause performance loss for a signal to be transmitted. For example, in another MMSE-THP nonlinear precoding algorithm (Tomlinson-Harashima precoding based on the minimum standard error, Tomlinson-Harashima precoding based on the minimum standard error), the preprocessing includes: performing QR decomposition for the matrix

to get the matrix Q and matrix B, where

,

is the noise power of the receiver, and

is the power of the signal v with limited power;

indicates a pseudoinverse matrix relative to the matrix H, and if the number of rows H is greater than or equal to the number of columns,

, or if the number of columns H exceeds the number of rows,

. The other steps of this algorithm are similar to the steps according to ZF-THP. Compared to ZF-THP, this algorithm considers noise and interference on the receiving side. For information on the module, the channel can be separately occupied for transmission, or information on the module can be transmitted together with other necessary communication signals. If information modulo is transmitted along with other necessary communication signals, it may not be necessary to take up an additional channel resource. Next, an LTE communication system is used as an example in order to briefly describe a method for transmitting information modulo.

[0039] Preferably, in step S405, information modulo is included in the transmission of control overhead signals in the downlink, which is used to indicate scheduling in the downlink. In particular, in the PDCCH (physical downlink control channel, physical downlink control channel), information is transmitted modulo together with scheduling information, which is used to indicate scheduling in the downlink to indicate whether or not modulo operation for the codeword PDSCH (physical downlink shared channel, physical downlink shared channel) indicated by disc information petcherization. PDSCH is used to carry data from a DSCH transmission channel (a downlink shared channel, a downlink shared channel), and is a DSCH carrier. The PDSCH codeword is a signal transmitted by a transmitter.

, если операция по модулю выполнена для данных, передаваемых на антенном порту на стороне передающего устройства, предположим, что

; либо если операция по модулю не выполнена для данных, передаваемых на антенном порту на стороне передающего устройства, предположим, что

. Альтернативно, может использоваться обратная обработка, т.е. когда не выполняется операция по модулю, предположим, что

, либо когда выполняется операция по модулю, предположим, что

. После того как информация по модулю загружается таким способом,

используется для того, чтобы заменять

, и используется в качестве нового конкретного для UE опорного сигнала, который затем предварительно кодируется и передается. Далее по-прежнему используется ZF-THP в качестве примера для того, чтобы пояснять правильность способа. В идеальном случае, после того, как конкретный для UE опорный сигнал поступает в приемное устройство, его эквивалентный канал является диагональным элементом L, но из признака QR-разложения матрицы может быть известно, что диагональный элемент L может задаваться с возможностью всегда составлять положительное действительное число (или отрицательное действительное число). Следовательно, когда UE на стороне передающего устройства выполняет оценку канала, всегда можно предполагать, что эквивалентный канал (или диагональный элемент L) составляет положительное действительное число (или отрицательное действительное число), и знак данных конкретного для UE опорного сигнала умножается на 1 (-1) и -1 (1), чтобы, соответственно, представлять случай, в котором выполняется операция по модулю, и случай, в котором не выполняется операция по модулю. В силу этого, UE на стороне приемного устройства может определять, посредством обнаружения знака конкретного для UE опорного сигнала, то, выполнена или нет операция по модулю для данных на антенном порту, соответствующем конкретному для UE опорному сигналу. Например, когда знак пилотного сигнала для конкретного для UE опорного сигнала является положительным, информация по модулю указывает то, что приемное устройство должно выполнять операцию по модулю для принимаемого сигнала; или когда знак пилотного сигнала для конкретного для UE опорного сигнала является отрицательным, информация по модулю указывает то, что приемное устройство не должно выполнять операцию по модулю для принимаемого сигнала, причем эквивалентный канал конкретного для UE опорного сигнала составляет положительное действительное число по умолчанию.[0040] Preferably, in step S405, the modulo information can alternatively be implicitly included in the reference signal specific to the UE (subscriber unit, subscriber unit). In particular, provided that the reference signal specific to the UE at the antenna port p is

if the modulo operation is performed for data transmitted on the antenna port on the side of the transmitting device, suppose that

; or if the modulo operation is not performed for data transmitted on the antenna port on the side of the transmitting device, suppose that

. Alternatively, reverse processing may be used, i.e. when the modulo operation is not performed, suppose that

, or when the operation is carried out modulo, suppose that

. After the module information is loaded in this way,

used to replace

, and is used as a new UE-specific reference signal, which is then precoded and transmitted. Further, ZF-THP is still used as an example in order to clarify the correctness of the method. In the ideal case, after the reference signal specific to the UE arrives at the receiving device, its equivalent channel is the diagonal element L, but from the sign of the QR decomposition of the matrix it can be known that the diagonal element L can be set with the ability to always be a positive real number (or a negative real number). Therefore, when the UE on the transmitter side performs channel estimation, it can always be assumed that the equivalent channel (or diagonal element L) is a positive real number (or a negative real number), and the data sign of the reference signal specific to the UE is multiplied by 1 (-1 ) and -1 (1) to respectively represent the case in which the modulo operation is performed and the case in which the modulo operation is not performed. Therefore, the UE on the receiver side can determine, by detecting the sign of the UE-specific reference signal, whether or not a modulo operation has been performed for data on the antenna port corresponding to the UE-specific reference signal. For example, when the sign of the pilot signal for the UE-specific reference signal is positive, the modulo information indicates that the receiver should perform the modulo operation for the received signal; or when the pilot sign for the UE-specific reference signal is negative, the modulo information indicates that the receiver should not perform the modulo operation for the received signal, the equivalent channel of the UE-specific reference signal being a positive real default number.

[0041] Referring to FIG. 5, FIG. 5 is a flowchart of a first embodiment of a precoding method on the receiver side according to the present invention. The method includes:

[0042] Step S500. Receiving information modulo transmitted by a transmitting device.

[0043] Preferably, in step S500, information modulo is included in the transmission of control overhead signals in the downlink, which is used to indicate scheduling in the downlink.

[0044] Preferably, in step S500, the module information is implicitly included in the UE-specific reference signal.

[0045] Step S501. Determining, according to the modulo information, whether or not the transmitting device performs a modulo operation for the signal after preprocessing. For example, if the information on the module is implicitly included in the reference signal specific to the UE, channel estimation can be performed for the equivalent channel of the reference signal specific to the subscriber unit, and then, the coefficient multiplied by the reference signal specific to the subscriber unit, 1 or -1, is determined according to the default sign of the real part of the equivalent channel of the reference signal specific to the subscriber device, and due to this, the meaning of the information is determined modulo. For example, when the sign of the pilot signal for the UE-specific reference signal is positive, the modulo information indicates that the receiver should perform the modulo operation for the received signal; or when the pilot sign for the UE-specific reference signal is negative, the modulo information indicates that the receiver should not perform the modulo operation for the received signal, the equivalent channel of the UE-specific reference signal being a positive real default number.

[0046] If the determination result in step S501 is “Yes”, step S502 is performed. Step S502. Performing a recovery operation modulo the received signal. Preferably, the modulo recovery operation process is identical to the modulo operation process.

[0047] If the determination result in step S501 is “No,” the method procedure ends.

[0048] In the precoding method provided by an embodiment of the present invention, whether or not to perform a module recovery operation for a received signal is determined according to the module information. Not only is the adverse effect exerted by the power limiting operation on signal transmission reduced, but the optional modulo recovery operation is also eliminated.

[0049] Referring to FIG. 6, FIG. 6 is a schematic structural diagram of a first embodiment of a transmission device according to the present invention. The transmitting device 60 includes.

[0050] The precoding preprocessing unit 610 is configured to pre-process the precoding for the signal to be transmitted, the preprocessing causing an increase in the power of the signal to be transmitted. For example, pre-processing may include all processing steps that can increase the signal power in a pre-coding algorithm, for example, processing to suppress sequential interference between signal streams.

[0051] The power limiting algorithm selection module 620 is configured to select a power limiting algorithm according to a selection rule. For example, a selection rule includes: selecting a power limitation algorithm with minimal performance loss, wherein the performance loss is the difference between the communication quality after the power limiting operation is performed and the communication quality when the power limiting operation is not performed. The selection rule may further include: selecting a power limitation algorithm that can generate minimal noise. The power limiting algorithm selection module 620 may select the most suitable of the previously stored power limiting algorithms in a particular case according to the selection rule.

[0052] The power limiting unit 630 is configured to perform a power limiting operation for a pre-processed signal according to a selected power limiting algorithm.

[0053] The precoded signal generating unit 640 is configured to generate a precoded signal according to a limited power signal. In particular, the pre-encoded signal generating unit 640 may perform some post-processing of the precoding for a signal with limited power. Post-processing may include the remaining processing steps after pre-processing and power limitation processing in the precoding algorithm are completed, for example, processing for converting a signal stream to an antenna.

[0054] In a transmitter provided by an embodiment of the present invention, various power limiting algorithms are adaptively selected in various cases. Not only is the transmission power controlled in such a way that it corresponds to the limitation of the hardware state, but also the adverse effect exerted by the power limiting operation on signal transmission is minimized as much as possible.

[0055] Referring to FIG. 7, FIG. 7 is a schematic structural diagram of a second embodiment of a transmission device according to the present invention. The transmitting device 70 includes.

, где u_k указывает предварительно обработанный сигнал, a_k указывает сигнал, который должен передаваться, b_kl указывает элемент в k-й строке и l-м столбце B, и v_l указывает сигнал с ограниченной мощностью. Как можно видеть из вышеприведенного процесса обработки, вследствие влияния члена

, расположенного в правой части формулы, мощность u_k выше мощности a_k, и, следовательно, необходимо выполнять операцию ограничения мощности для сигнала после обработки предварительного кодирования таким образом, ограничивать мощность передачи.[0056] The precoding preprocessing unit 710 is configured to pre-process the precoding for the signal to be transmitted, the preprocessing causing an increase in the power of the signal to be transmitted. Using ZF-THP as an example and assuming that the numbers of antennas on the side of the receiving device and the side of the transmitting device are symmetrical and are K, and that the signals to be transmitted are a ₁ , a ₂ ..., a _K , processing pre-coding includes: obtaining a channel matrix H according to the feedback of the receiving device or obtaining an approximate channel matrix H of the downlink according to the estimation of the pilot channel of the uplink and decomposition H to obtain ^H = LQ H, where L is a lower triangular matrix with size K × K, Q is a unitary matrix with dimensions K × K, and the expansion can be realized through the QR-decomposition ^H H, where ^H H indicates conjugate transpose of H; then obtaining the matrix B according to B = GL, where G is a diagonal matrix including the inverse values of the diagonal elements of L, and therefore B is a lower triangular matrix whose diagonal elements are 1; and calculating pre-processed signals according to

where u _k indicates a pre-processed signal, a _k indicates a signal to be transmitted, b _kl indicates an element in the kth row and lth column B, and v _l indicates a signal with limited power. As can be seen from the above processing process, due to the influence of the member

located on the right side of the formula, the power u _{k is} higher than the power a _k , and therefore, it is necessary to perform the power limiting operation for the signal after precoding processing in this way, to limit the transmit power.

[0057] The power limiting algorithm selection module 720 is configured to determine, according to a selection rule, whether or not to select an algorithm with a modulo operation from an algorithm with a modulo operation and a power limitation algorithm without a modulo operation. The modulo operation algorithm includes: determining the modulo offset and using the sum of the modulo offset and the pre-processed signal as a signal after the modulo operation, the signal amplitude after the modulo operation not exceeding a predetermined amplitude threshold value. A power limiting algorithm without a modulo operation may include a linear power limiting algorithm or any nonlinear power limiting algorithm, with the exception of a modulo operation algorithm. When using the linear power limitation algorithm as an example, the algorithm includes: determining the power limiting coefficient and multiplying the power limiting coefficient by a pre-processed signal or multiplying the power limiting coefficient by the signal to be transmitted, which is included in the pre-processed signal, and using the signal after calculating the multiplication as a signal after the linear power limitation operation, the power of the linear ogre operation power reduction does not exceed a preset threshold power value. Although the modulo operation and the linear power limiting operation can well limit the power, and compared to skipping, the power limiting operations have performance losses, the performance losses caused by them vary depending on different cases. For example, when the channel condition and / or channel quality is poor, the performance losses caused by the linear power limiting operation are very large; when the channel state and / or channel quality is relatively good, the linear performance performance limitation of the operation can be less than the modular operation loss. Therefore, the selection rule may include: selecting one of the algorithm with a modulo operation and the linear power limitation algorithm according to the current channel state and / or channel quality. For example, when the measurement value of one or more indicators of the current channel state and / or channel quality exceeds a predetermined threshold value, it is considered that the modulo operation performance loss is less than the linear power limitation operation performance loss, and therefore, the power limitation algorithm selection module 720 selects an algorithm with a modulo operation; or when the measurement value of one or more indicators of the current channel state and / or channel quality is less than a predetermined threshold value, it is considered that the modulo operation performance loss is greater than the linear power limitation operation performance loss, and therefore, the power limitation algorithm selection module 720 selects an algorithm linear power limitation. Indicators of channel status and / or channel quality include a signal-to-noise ratio, correlation between antennas, channel correlation between users, and the like. In order to provide better communication quality, the power limiting algorithm selection module 720 may select a power limiting algorithm based on a more complex coefficient. For example, the power limit algorithm selection module 720 may determine, according to the performance loss of the algorithm with the modulo operation and the performance loss of the linear power limitation algorithm, whether or not to select the algorithm with the modulo operation. The following uses the modulo operation algorithm and the linear power limitation algorithm as examples to describe in detail how the power limitation algorithm selection module 720 estimates the performance loss.

[0058] Preferably, the power limiting algorithm selection module 720 may estimate the modulus loss of operation of the operation modulo according to the current channel condition, channel quality, and / or the current modulation and coding scheme. In particular, the power limitation algorithm selection module 720 may evaluate, according to the current channel state and / or channel quality and the pre-stored performance losses of the modulo operations in various channel conditions and / or channel quality, the performance losses that can be caused by using the modulo operation in this case, and / or can evaluate, according to the current modulation and coding scheme and the previously saved performance losses of the module operations in various schemes x modulation and coding, performance losses that can be caused by using the modulo operation in this case. The performance loss of an algorithm with a modulo operation in different channel conditions and / or channel quality or in various modulation and coding schemes can be determined using a method such as precalculation, preliminary modeling, or preliminary measurement.

, по сравнению с мощностью полезного сигнала до того, как выполняется нормализация, потери мощности полезного сигнала после операции ограничения мощности (выражаемые в форме дБ) составляют

. В частности, модуль 720 выбора алгоритма ограничения мощности может оценивать потери производительности операции линейного ограничения мощности согласно потерям мощности для мощности полезного сигнала после операции линейного ограничения мощности, относительно мощности полезного сигнала перед операцией линейного ограничения мощности и соответствия между предварительно сохраненными потерями мощности и потерями производительности, причем соответствие между потерями мощности и потерями производительности может получаться посредством использования такого способа, как предварительное моделирование, предварительное вычисление или предварительное измерение. Помимо этого, модуль 720 выбора алгоритма ограничения мощности может непосредственно использовать потери мощности для мощности полезного сигнала после операции линейного ограничения мощности, относительно мощности полезного сигнала перед операцией линейного ограничения мощности, в качестве потерь производительности операции линейного ограничения мощности.[0059] Preferably, the power limiting algorithm selection module 720 may estimate the performance loss of the linear power limiting algorithm according to the power loss for the useful signal power after the linear power limiting operation, relative to the useful signal power before the linear power limiting operation. For example, provided that the power limiting coefficient calculated according to the above method is

, compared with the power of the useful signal before normalization is performed, the power loss of the useful signal after the power limiting operation (expressed in dB form) is

. In particular, the power limiting algorithm selection module 720 may evaluate the performance loss of the linear power limiting operation according to the power loss for the useful signal power after the linear power limiting operation, with respect to the useful signal power before the linear power limiting operation and the correspondence between the previously saved power loss and performance loss moreover, the correspondence between power losses and performance losses can be obtained through tion using a method such as a preliminary simulation prior calculation or prior measurement. In addition, the power limiting algorithm selection module 720 can directly use the power loss for the useful signal power after the linear power limiting operation, relative to the useful signal power before the linear power limiting operation, as the performance loss of the linear power limiting operation.

, где

является смещением по модулю. Посредством выполнения операции по модулю, действительная часть и мнимая часть

ограничены рамками диапазона, и, следовательно, его мощность также ограничена рамками целевого диапазона.[0060] The module operation execution module 730 is configured to perform the module operation for the signal after precoding preprocessing, when the result of determining the power limitation algorithm selection module 720 is “Yes”, the module operation including the sum of the module bias with a signal after preprocessing precoding. Also, when using ZF-THP as an example for description, the signal after the operation modulo is

where

is the offset modulo. By performing the modulo operation, the real part and the imaginary part

limited by the range, and therefore its power is also limited by the range of the target range.

ограничения мощности, так что мощность сигнала

после операции линейного ограничения мощности не превышает предварительно установленное пороговое значение мощности.[0061] The power limiting module 740 without a modulo operation is configured to perform a power limiting operation without a modulo operation for a signal after preprocessing pre-coding, for example, a linear power limiting operation when the determination result of the power limiting algorithm selection module 720 is “No " Using ZF-THP as an example, a linear power limiting operation includes: determining a coefficient

power limits so that the signal power

after the operation of linear power limitation does not exceed a preset threshold power value.

, где

и

.[0062] The pre-encoded signal generating unit 750 is configured to post-process the precoding for the signal after the modulo operation or the linear power limiting operation and generate a pre-encoded signal. Also, when using ZF-THP as an example to describe the post-processing of precoding, the post-processing includes: multiplying the signal v _k (k = 1, 2 ..., K) after the modulo operation or the operation of linear power limitation by the matrix Q, obtained by pre-processing, in order to obtain a pre-encoded signal x _k (k = 1, 2 ..., K), namely,

where

and

.

[0063] The module information transmitting module 760 is configured to transmit, to the receiver, the module information, which is used to indicate whether or not the transmitting device performs the module operation for the signal after preprocessing, so that the receiver the device determines, according to the modulo information, whether or not to perform a modulo recovery operation for the received signal. The modulo recovery operation performed by the receiver is identical to the modulo operation performed by the transmitter. Since the modulo operation can interfere with the desired signal, in order to reduce the modulo operation performance loss, it is necessary to perform, on the receiver side, a modulo recovery operation that is completely identical to the modulo recovery operation on the side of the transmitting recovery unit. However, if linear power limitation is used in the power limitation algorithm on the transmitter side, it is not necessary to perform a module recovery operation for the received signal on the receiver side to recover. Therefore, by transmitting, to the receiver, modulo information to indicate whether or not the modulo operation for the signal is performed after preprocessing the precoding, the performance loss in signaling can be reduced more appropriately, losses caused by performing an optional recovery operation are eliminated modulo for the receiver side, and communication quality is improved.

, чтобы получать матрицу Q и матрицу B, где

,

является мощностью шума приемного устройства, и

является мощностью сигнала v с ограниченной мощностью;

указывает псевдообратную матрицу относительно матрицы H, и если количество строк H превышает или равно количеству столбцов,

, либо если количество столбцов H превышает количество строк,

. Другие этапы этого алгоритма являются аналогичными этапам согласно ZF-THP. По сравнению с ZF-THP, этот алгоритм рассматривает шум и помехи на стороне приемного устройства. Для информации по модулю, канал может отдельно заниматься для передачи, или информация по модулю может передаваться вместе с другими необходимыми сигналами связи. Если информация по модулю передается вместе с другими необходимыми сигналами связи, может быть необязательным занимать дополнительный ресурс канала. Далее используется LTE-система связи в качестве примера для того, чтобы кратко описывать способ для передачи информации по модулю посредством модуля 760 передачи информации по модулю.[0064] Although this embodiment is described by using ZF-THP as an example, the present invention is not limited to the ZF-THP precoding algorithm, and may be applicable to any precoding algorithm that may cause performance loss for a signal to be transmitted. For example, in another MMSE-THP nonlinear precoding algorithm (Tomlinson-Harashima precoding based on the minimum standard error, Tomlinson-Harashima precoding based on the minimum standard error), the preprocessing includes: performing QR decomposition for the matrix

to get the matrix Q and matrix B, where

,

is the noise power of the receiver, and

is the power of the signal v with limited power;

indicates a pseudoinverse matrix relative to the matrix H, and if the number of rows H is greater than or equal to the number of columns,

, or if the number of columns H exceeds the number of rows,

. The other steps of this algorithm are similar to the steps according to ZF-THP. Compared to ZF-THP, this algorithm considers noise and interference on the receiving side. For information on the module, the channel can be separately occupied for transmission, or information on the module can be transmitted together with other necessary communication signals. If information modulo is transmitted along with other necessary communication signals, it may not be necessary to take up an additional channel resource. Next, an LTE communication system is used as an example in order to briefly describe a method for transmitting information modulo by module 760 for transmitting information modulo.

[0065] Preferably, the module information transmitting module 760 can transmit the module information by including the module information in the transmission of control overhead signals in the downlink, which is used to indicate scheduling in the downlink. In particular, in the PDCCH (physical downlink control channel, physical downlink control channel), the module information transmitting module 760 may transmit module information together with scheduling information, which is used to indicate scheduling in the downlink, to indicate whether or not a modulo operation has been performed for the codeword PDSCH (physical downlink shared channel, physical downlink shared channel ide) indicated by dispatch information. PDSCH is used to carry data from a DSCH transmission channel (a downlink shared channel, a downlink shared channel), and is a DSCH carrier. The PDSCH codeword is a signal transmitted by a transmitter.

, если операция по модулю выполнена для данных, передаваемых на антенном порту на стороне передающего устройства, предположим, что

; либо если операция по модулю не выполнена для данных, передаваемых на антенном порту на стороне передающего устройства, предположим, что

. Также может использоваться обратная обработка, т.е. когда не выполняется операция по модулю, предположим, что

, либо когда выполняется операция по модулю, предположим, что

. После того как информация по модулю загружается таким способом,

используется для того, чтобы заменять

, и используется в качестве нового конкретного для UE опорного сигнала, который затем предварительно кодируется и передается. Далее по-прежнему используется ZF-THP в качестве примера для того, чтобы пояснять правильность способа. В идеальном случае, после того как конкретный для UE опорный сигнал поступает в приемное устройство, его эквивалентный канал является диагональным элементом L, но из признака QR-разложения матрицы может быть известно, что диагональный элемент L может задаваться с возможностью всегда составлять положительное действительное число (или отрицательное действительное число). Следовательно, когда UE на стороне передающего устройства выполняет оценку канала, всегда можно предполагать, что эквивалентный канал (или диагональный элемент L) составляет положительное действительное число (или отрицательное действительное число), и знак данных конкретного для UE опорного сигнала умножается на 1 (-1) и -1 (1), чтобы, соответственно, представлять случай, в котором выполняется операция по модулю, и случай, в котором не выполняется операция по модулю. В силу этого, UE на стороне приемного устройства может определять, посредством обнаружения знака конкретного для UE опорного сигнала, то, выполнена или нет операция по модулю для данных на антенном порту, соответствующем конкретному для UE опорному сигналу. Например, когда знак пилотного сигнала для конкретного для UE опорного сигнала является положительным, информация по модулю указывает то, что приемное устройство должно выполнять операцию по модулю для принимаемого сигнала; или когда знак пилотного сигнала для конкретного для UE опорного сигнала является отрицательным, информация по модулю указывает то, что приемное устройство не должно выполнять операцию по модулю для принимаемого сигнала, причем эквивалентный канал конкретного для UE опорного сигнала составляет положительное действительное число по умолчанию.[0066] Preferably, the module information transmitting module 760 can transmit the module information by implicitly including the module information in a reference signal specific to the UE (subscriber unit, subscriber unit). In particular, provided that the reference signal specific to the UE at the antenna port p is

if the modulo operation is performed for data transmitted on the antenna port on the side of the transmitting device, suppose that

; or if the modulo operation is not performed for data transmitted on the antenna port on the side of the transmitting device, suppose that

. Reverse processing may also be used, i.e. when the modulo operation is not performed, suppose that

, or when the operation is carried out modulo, suppose that

. After the module information is loaded in this way,

used to replace

, and is used as a new UE-specific reference signal, which is then precoded and transmitted. Further, ZF-THP is still used as an example in order to clarify the correctness of the method. In the ideal case, after the reference signal specific to the UE arrives at the receiving device, its equivalent channel is the diagonal element L, but from the sign of the QR decomposition of the matrix it can be known that the diagonal element L can be set with the ability to always be a positive real number ( or a negative real number). Therefore, when the UE on the transmitter side performs channel estimation, it can always be assumed that the equivalent channel (or diagonal element L) is a positive real number (or a negative real number), and the data sign of the reference signal specific to the UE is multiplied by 1 (-1 ) and -1 (1) to respectively represent the case in which the modulo operation is performed and the case in which the modulo operation is not performed. Therefore, the UE on the receiver side can determine, by detecting the sign of the UE-specific reference signal, whether or not a modulo operation has been performed for data on the antenna port corresponding to the UE-specific reference signal. For example, when the sign of the pilot signal for the UE-specific reference signal is positive, the modulo information indicates that the receiver should perform the modulo operation for the received signal; or when the pilot sign for the UE-specific reference signal is negative, the modulo information indicates that the receiver should not perform the modulo operation for the received signal, the equivalent channel of the UE-specific reference signal being a positive real default number.

[0067] Referring to FIG. 8, FIG. 8 is a schematic structural diagram of a first embodiment of a receiving device according to the present invention. The receiving device 80 includes.

[0068] The module information reception module 810 is configured to receive module information transmitted by a transmitter.

[0069] Preferably, the module information is included in the transmission of control overhead signals in the downlink, which is used to indicate scheduling in the downlink.

[0070] Preferably, the module information is implicitly included in the UE-specific reference signal.

[0071] The module 820 for determining the execution of a modulo operation is configured to determine, according to the modulo information, whether or not the transmitting device performs a modulo operation for the signal after precoding preprocessing.

[0072] Preferably, the module operation determining module 820 can perform channel estimation for the equivalent channel of the user-specific reference signal and determine, according to the default sign of the real part of the equivalent channel of the user-specific reference signal, then the coefficient multiplied by a reference signal specific to the subscriber device, 1 or -1, and thereby determine the meaning of the information modulo. For example, when the sign of the pilot signal for the UE-specific reference signal is positive, the modulo information indicates that the receiver should perform the modulo operation for the received signal; or when the pilot sign for the UE-specific reference signal is negative, the modulo information indicates that the receiver should not perform the modulo operation for the received signal, the equivalent channel of the UE-specific reference signal being a positive real default number.

[0073] The module 830 for performing a module recovery operation is configured to perform a module recovery operation for a received signal if the result of determining the module operation determining module 820 is “Yes”. Preferably, the modulo recovery operation performed by the modulo 830 modulo recovery operation module is identical to the modulo operation performed by the modulo module.

[0074] In a receiver provided by an embodiment of the present invention, whether or not to perform a module recovery operation for a received signal is determined according to the module information. Not only is the adverse effect exerted by the power limiting operation on signal transmission reduced, but the optional modulo recovery operation is also eliminated.

[0075] The present invention further provides a precoding system and a precoding method implemented by using a precoding system. The precoding system includes a transmitter and a receiver as described in any of the above embodiments.

[0076] Those of ordinary skill in the art may understand that all or some of the processes in the methods of embodiments may be implemented by a computer program that instructs relevant hardware. The program may be stored on a computer-readable storage medium. When the program is executed, processes in the methods of the embodiments are carried out. The above storage medium may include: a magnetic disk, an optical disk, read-only memory (read-only memory, ROM) or random access memory (random access memory, RAM).

[0077] What is disclosed above is merely exemplary embodiments of the present invention and, of course, does not intend to limit the scope of protection of the present invention. Those skilled in the art may understand that all or some of the processes that implement the above embodiments and equivalent modifications made in accordance with the claims of the present invention should fall within the scope of the present invention.

Claims (48)

1. The method of pre-coding, comprising stages in which: pre-coding is pre-processed for the signal to be transmitted, wherein the pre-processing causes an increase in the power of the signal to be transmitted; selecting a power limiting algorithm according to a selection rule; performing a power limiting operation for the pre-processed signal according to the selected power limiting algorithm; and generating a precoded signal according to a signal with limited power; wherein the selection rule comprises a step in which: a power limitation algorithm is selected with minimal performance loss, wherein the performance loss is the difference between the communication quality after the power limiting operation is performed and the communication quality when the power limiting operation is not performed. 2. The precoding method according to claim 1, wherein the power limiting algorithm comprises an algorithm with a modulo operation and a power limiting algorithm without a modulo operation; and - the step of selecting a power limitation algorithm according to the selection rule comprises the step of: selecting one of the algorithm with modulo operation and the power limitation algorithm without modulo operation according to the selection rule; wherein the algorithm with the modulo operation contains the steps in which: the modulo offset is determined and the sum of the modulo offset and the pre-processed signal are used as the signal after the modulo operation, and the signal amplitude after the modulo operation does not exceed a predetermined threshold amplitude value. 3. The precoding method according to claim 2, wherein the method further comprises the step of: transmitting, to the receiver, information modulo, which is used to indicate whether or not the transmitting device performs modulo operation for the pre-processed the signal by which precoding preprocessing is performed. 4. The pre-coding method according to claim 1, wherein the step of generating the pre-coded signal according to the limited power signal, in particular, comprises: post-processing the pre-coding for the limited power signal and generating a pre-coded signal. 5. The pre-coding method according to claim 2, wherein the power limiting algorithm without modulo operation comprises a linear power limiting algorithm, wherein the linear power limiting algorithm comprises the steps of: determining a power limiting coefficient and multiplying the power limiting coefficient by a pre-processed signal or multiplying the power limiting factor by the signal to be transmitted, which is contained in the pre-processed signal, and using the multiplied signal l as a signal after a power limiting operation without a modulo operation, while the signal power after a power limiting operation without a modulo operation does not exceed a preset threshold power value. 6. The precoding method according to claim 1, wherein the power loss of the power limiting algorithm is estimated according to the power loss for the useful signal power after the power limiting operation corresponding to the power limiting algorithm, relative to the useful signal power before the power limiting operation. 7. The pre-coding method according to claim 2, in which the performance loss of the algorithm with a modulo operation is estimated according to the current channel state, channel quality, or the current modulation and coding scheme. 8. The precoding method of claim 3, wherein the modulo information is contained in the transmission of control overhead signals in a downlink, which is used to indicate scheduling in a downlink. 9. The pre-coding method according to claim 3, in which the module information is implicitly contained in a reference signal specific to the subscriber device. 10. The pre-coding method according to claim 9, in which the modulo information is indicated by a sign times 1 or -1 specific to the subscriber device of the reference signal, while the sign of the real part of the equivalent channel specific to the subscriber device of the reference signal is positive or negative default. 11. A precoding method comprising the steps of: receiving modulo information transmitted by the transmitter, the modulo information being used to indicate whether or not the transmitter has performed the modulo operation for the signal after precoding; and determine, according to the modulo information, whether or not the transmitting device performs a modulo operation for the pre-processed signal, and if the determination result is “Yes”, a modulo restore operation is performed for the received signal. 12. The pre-coding method according to claim 11, wherein the module information is implicitly contained in a reference signal specific to the subscriber device; and the step of determining, according to the modulo information, whether or not the transmitting device performs a modulo operation for the pre-processed signal, in particular, it comprises the step of: perform channel estimation for the equivalent channel of the reference signal specific for the subscriber unit and determine, according to the default sign of the real part of the equivalent channel of the reference signal specific for the subscriber device, the coefficient multiplied by the reference signal specific for the subscriber device is 1 or -1. 13. A transmitting device comprising: a pre-coding pre-processing module adapted to pre-coding pre-processing for the signal to be transmitted, wherein the pre-processing causes an increase in the power of the signal to be transmitted; a power limiting algorithm selection module configured to select a power limiting algorithm according to a selection rule; a power limiting module configured to perform a power limiting operation for a pre-processed signal according to a selected power limiting algorithm; and a module for generating precoded signals, configured to generate a precoded signal according to a signal with limited power; wherein the power limitation algorithm comprises an algorithm with a modulo operation and a power limitation algorithm without a modulo operation; and the power limit algorithm selection module is configured to select one of the modulo operation algorithm and the power limit algorithm without modulo operation according to the selection rule. 14. The transmitting device according to claim 13, wherein the transmitting device further comprises: a module information transmission module, configured to transmit, to a receiver, module information that is used to indicate whether or not the transmitter is performing the module operation for a pre-processed signal. 15. A receiving device comprising: a module information receiving module configured to receive module information transmitted by the transmitter, the module information being used to indicate whether or not the transmitter has performed module operation for the signal after preprocessing; a module operation determination module, configured to determine, according to the module information, whether or not the transmitting device performs a module operation for the signal after preprocessing; and a module for performing a module recovery operation, configured to perform a module repair operation for a received signal if the result of determining the module for determining a module operation is “Yes”. 16. A pre-coding system comprising a transmitting device and a receiving device, the transmitting device comprising: - a pre-coding pre-processing module, configured to pre-coding pre-processing for the signal to be transmitted, wherein the pre-processing causes an increase in the power of the signal to be transmitted; - a module for selecting a power limiting algorithm, configured to select a power limiting algorithm according to a selection rule; a power limiting module configured to perform a power limiting operation for a pre-processed signal according to a selected power limiting algorithm; and - a module for generating precoded signals, configured to generate a precoded signal according to a signal with limited power; wherein the selection rule comprises a step in which: a power limitation algorithm is selected with minimal performance loss, wherein the performance loss is the difference between the communication quality after the power limiting operation is performed and the communication quality when the power limiting operation is not performed. 17. The pre-coding system according to claim 16, in which: - the transmitting device further comprises: - a module information transmitting module, configured to transmit module information to the receiver, which is used to indicate whether or not the transmitting device performs the module operation for the pre-processed signal; and - the receiving device contains: - module information receiving module, configured to receive module information transmitted by a transmitting device; - a module for determining the execution of an operation modulo, configured to determine, according to the information modulo, whether or not the transmitting device performs an operation modulo a pre-processed signal; and - a module for performing a module recovery operation, configured to perform a module recovery operation for a received signal if the result of determining the module for determining the module operation is “Yes”.

Images