KR20180057611A - Signal transmission method, signal reception method, transmitter and receiver - Google Patents

Abstract

The present application provides a method for transmitting a signal, the method comprising: transmitting link grouping configuration information by a transmitter, the link grouping configuration information comprising: dividing a link into at least two groups, Link, which is information of a link; Layering a data flow to be transmitted according to a grouping of links by a transmitter; Performing spatial modulation on the layered data flow by a transmitter; Performing, by the transmitter, multicarrier modulation on the spatially modulated signal; And transmitting by the transmitter a multicarrier modulated signal. The present application further provides a signal receiving method, a transmitter and a receiver. The present application utilizes features of spatial modulation systems to provide different levels of protection for different data flows, so that users of different channel conditions can obtain different quality of service.

Description

Signal transmission method, signal reception method, transmitter and receiver

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to wireless communication technology, and more particularly, to a signal transmission method, a signal reception method, a transmitter, and a receiver.

The rapid development of the information and communications industry, especially the growing demand for mobile Internet and Internet of Things (IoT), presents an unprecedented challenge to future mobile technology. According to ITU-R M. (IMT.BEYOND 2020.TRAFFIC) issued by the International Telecommunication Union (ITU), mobile service traffic will increase by almost 1,000 times compared to 2010 (4G age) by 2020, The number of IoT devices is also expected to grow to more than 17 billion, the number of IoT devices will gradually expand to mobile communication networks, and the number of connected devices will be much larger. In response to these unprecedented challenges, the telecommunications industry and academia have begun extensive research on 5G mobile technology (5G) and prepared them for 2020. At present, ITU-R M. [IMT.VISION] from ITU discusses the framework and overall objectives of the future 5G, detailing the demand forecasts, application scenarios and various important performance indicators of 5G. In terms of the new requirements of 5G, ITU-R M. [IMT.FUTURE TECHNOLOGY TRENDS] from ITU provides information related to the 5G technology trend, which is a significant improvement in system throughput, consistent user experience, IoT, , Scalability to support energy efficiency, cost, network flexibility, new service support and flexible spectrum utilization.

Multiple-input multiple-output (MIMO) technology is an important technique for improving system spectral efficiency. As the MIMO technology can effectively improve the system data rate and improve the system link stability, it is possible to use the 3rd Generation Partnership Project (3GPP), the European DVB (Digital Video Broadcasting) and the IEEE802. (Long Term Evolution) system corresponding to Evolved Universal Terrestrial Radio Access (E-UTRA) formalized by WiMAX (Worldwide Interoperability for Microwave Access). By forming a communication link between the transmitting and receiving antennas on the receiving side, the MIMO technique can provide spatial diversity gain and spatial multiplexing gain to the system. By transmitting the same data on different links, the MIMO technique can improve the reliability of data transmission and obtain diversity gain; By transmitting different data on different links, the MIMO technique can improve the system spectral efficiency without increasing the transmission bandwidth and improve the transmission data rate. Due to the channel state information of the transmitting side, the MIMO technique can further improve the spectral efficiency of the entire system by serving a plurality of users having the same time-frequency resources together with precoding. Currently, MIMO technology is a core technology that can support 4G MBB (Mobile Broadband) service needs. In 5G, the existing MIMO technology will be difficult to meet the greatly improved data rate because the demand for spectral efficiency, energy efficiency and data rate will be better. Thus, evolved MIMO technology, that is, large scale MIMO technology, has gained wide interest from academia and industry. By placing far more antennas than the number of users at the transmitting end, large-scale MIMO techniques can achieve more array processing gains (finer beams) and more spatial degrees of freedom, and with simple linear behavior, It can be completely distinguished, and thus the spectral efficiency and energy efficiency can be further improved. However, in practical application scenarios, there have been some problems with MIMO technology as well as with large-scale MIMO technology. For example: 1. Whether the MIMO technique is effective or reliable depends on whether accurate channel state information can be obtained at the transmitting end. If the channel state information on the transmitting side is not sufficiently accurate, a significant reduction in system gain will result. Current MIMO techniques rely on channel estimation based on reference signals and feedback. However, as the number of antennas increases, the overhead associated with the reference signal and feedback will severely reduce system spectral efficiency. 2. The requirements for synchronization between antennas are strict. 3. Inter-channel interference needs to be handled at the receiving end. 4. Although multi-user MIMO can improve the overall spectral efficiency of the cell, it does not help to improve single-user spectral efficiency.

As a field of MIMO technology, SM (Spatial Modulation) has become widespread in academia in recent years. The SM technique uses a portion of the information bits to select the transmit antenna with only one antenna for each transmission. By using an antenna index as an additional carrier wave for transmitting information, a three-dimensional constellation is constructed based on a normal two-dimensional constellation, resulting in higher spectral efficiency than a single antenna system. On the other hand, SM technology solved some problems of conventional MIMO technology. For example, since each transmission uses only a single antenna, the SM technique does not need to perform complex inter-antenna synchronization and elimination of inter-link interference at the receiving end, simplifying the process at the receiving end; SM technology can improve single user spectral efficiency and is therefore more appropriate for some scenarios where there is a need to improve single user data rates; Since the SM technique does not require precoding on the transmit side, no feedback is required on the receive side; The transmitting side requires only one RF link, which greatly reduces the overhead of the transmitting side. Multicarrier-based SM techniques lose the benefit of a single RF link, but the allocation of time-frequency two-dimensional resources provides a higher degree of freedom for the system and also provides better robustness for frequency selective fading caused by multipath Respectively.

Advantages of SM technology are becoming widespread in communication research. Characteristics that do not require channel feedback and that do not have a requirement for the number of antennas at the receiving end can be particularly suitable for broadcasting data or transmitting data in open loop mode. In order to extend the application of spatial modulation techniques in 5G and take advantage of spatial modulation techniques, it is necessary to deeply explore their properties in different application scenarios and to improve their methods.

A technical problem to be solved by the present invention is that a cellular system can not provide differentiated services to users in different channel conditions during transmission of broadcast data. To this end, the present application provides a signal transmission method, a reception method, a transmitter and a receiver, which use features of a spatial modulation system to provide different levels of protection for different data flows, so that users with different channel conditions To be able to receive the service.

The present invention provides a signal transmission method,

The method comprising: transmitting link grouping setting information by a transmitter, the link grouping setting information being information of a link included in each group after dividing the link into at least two groups;

Layering a data flow to be transmitted according to a grouping of links by a transmitter;

Performing spatial modulation on the layered data flow by a transmitter;

Performing, by the transmitter, multicarrier modulation on the spatially modulated signal; And

And transmitting, by the transmitter, a multi-carrier modulated signal.

Advantageously, dividing the link into at least two groups comprises: splitting all available links into at least two groups, wherein the generated group is a group of a first layer; Further dividing each of the groups of the first hierarchy into at least two groups, wherein the generated group is a group of the second hierarchy; And performing such segmentation until each group contains only one link or the setting requirements of the link grouping are satisfied, by such analogy.

Preferably, layering the data flow to be transmitted in accordance with the grouping of the links by the transmitter comprises transmitting the basic data using the group of the first layer and transmitting the basic data using the group of the first layer, And sending the assistance data using each group of layers; The auxiliary data includes at least one of extended data based on basic data, redundant information of data of a previous layer, and a combination of the extended data and redundant information.

Preferably, the criterion for dividing the link into groups is to assign the links having a correlation index greater than the setting threshold to a group.

Advantageously, the method further comprises: estimating, by the transmitter, a correlation index between the links according to information from the receiver, and thereby dynamically adjusting the number of links and the grouping of the links; The information from the receiver includes channel state information fed back from the receiver and / or a sounding reference signal sent to the transmitter via the uplink channel by the receiver.

Preferably, the method further comprises assigning users with the same link grouping configuration information to one group, and performing broadcast services on the same time-frequency resource for users in the same group.

Preferably, the method further comprises performing multi-carrier modulation and transmission after pre-processing the spatially modulated signal.

Advantageously, said pre-processing step comprises performing power adjustment on the link and / or phase adjustment on the link.

Advantageously, performing the power adjustment on the link comprises: adjusting each average transmit power of the group in the first layer such that each of the groups has a different average transmit power, while maintaining transmit power unchanged; Adjusting the average transmit power of each of the groups in the second layer such that each of the groups of the second layer can have different average transmit power while maintaining the average transmit power of each of the groups in the first layer unchanged ; And performing an adjustment by such analogy until adjustment of the average transmission power of each of the groups of the lowest layer is completed.

Preferably, the criterion for adjusting the average transmit power of the group at each layer is that the power adjustment amount of the layer is not greater than the power adjustment amount of the previous layer.

Advantageously, performing phase adjustment on the link comprises randomly selecting a rotational phase for each link of the group of the lowest hierarchy, wherein the interval of each rotational phase of the links belonging to the different group is not cross And selecting adjacent rotation phase intervals for each link of the group belonging to the same group in the previous layer.

Preferably, the method includes using constellation point symbols of spatial modulation to transmit data in the lowest layer or to transmit other supplemental or redundant information.

Advantageously, the method further comprises transmitting, by the transmitter, a reference signal in accordance with the grouping of the links.

Preferably, the step of transmitting, by the transmitter, the reference signal in accordance with the grouping of the links comprises the steps of: transmitting, by the transmitter, the same time-frequency resources for the links belonging to the same group And transmitting the same reference signal sequence using the same reference signal sequence.

Advantageously, if the multicarrier modulation and transmission are performed after pre-processing the spatially modulated signal, performing the pre-processing on the reference signal before transmitting the reference signal.

Advantageously, the method further comprises dividing the layered data in each of the layers into blocks, and adding a cyclic redundancy check (CRC) code independent of the data in each layer of each block of data .

Preferably, the transmitter transmits link number information and link grouping configuration information in at least one of a physical broadcast channel, a physical downlink control channel, and a physical downlink shared channel.

Preferably, the transmitter transmits on a physical broadcast channel, a physical downlink control channel, or a physical downlink shared channel with additional fields added, said additional fields indicating link number information and link grouping configuration information.

Preferably, the transmitter transmits link count information using a CRC check mask of the physical broadcast channel, each of the transmission modes of the physical broadcast channel corresponds to at least two CRC checkmasks, and each CRC checkmask Corresponds to one kind of information about the number of links; The transmission mode of the physical broadcast channel includes a single antenna port transmission mode, a dual antenna port transmission diversity mode, and a four antenna port transmission diversity mode;

The transmitter transmits on a physical broadcast channel, a physical downlink control channel or a physical downlink shared channel with additional fields added, and the additional field indicates link grouping configuration information.

The present application further provides a transmitter,

A setting module that transmits link grouping setting information, wherein the link grouping setting information is information of a link included in each group after dividing the link into at least two groups;

A data layering module for layering a data flow to be transmitted according to grouping of links;

A spatial modulation module for performing spatial modulation on the layered data flow;

A multi-carrier modulation module for performing multi-carrier modulation on a space-modulated signal; And

And a transmitting module for transmitting the multi-carrier modulated signal.

The present application also provides a method of signal reception. The method comprises:

Receiving, by the receiver, link grouping setting information;

Obtaining, by a receiver, grouping of links included in each of the groups according to the link grouping setting information and information of links; And

And performing, by the receiver, layered detection of the received data according to the grouping of the links.

Advantageously, the step of performing, by the receiver, layered detection of the received data according to the grouping of the link,

Detecting, by a receiver, data transmitted from all layers according to channel status information of each link, and determining the number of layers to be maintained according to a setting criterion; Wherein the setting criteria comprises: comparing a previously set signal-to-noise ratio threshold and an estimated signal-to-noise ratio of detected data from each layer; and if the signal-to-noise ratio threshold is greater than the threshold, And performing subsequent processing, but not performing subsequent processing; Or the setting criterion comprises determining, by the transmitter, whether to maintain the data of the corresponding layer for each receiver according to whether a CRC check added by the transmitter independently for each layer of data has passed .

Preferably, the method further comprises the steps of: detecting data of each layer by layer according to channel state information of each group; and estimating the estimated signal-to-noise ratio of detected data from each of the layers with a preset signal- Comparing the signal-to-noise ratio threshold with the signal-to-noise ratio threshold, and if the signal-to-noise ratio threshold is higher than the signal-to-noise ratio threshold, performing subsequent detection of data in the next layer;

Advantageously, the method further comprises, by a receiver, receiving a reference signal according to grouping of links and performing channel estimation.

The present application further provides a receiver,

A setting information receiving module for receiving the link grouping setting information;

A grouping acknowledgment module for obtaining link grouping and link information included in each of the groups according to the link grouping setting information;

And a detection module that performs layered detection on the received data according to the grouping of the links.

The present disclosure also provides a method of signal transmission based on multi-carrier spatial modulation. In this method,

The transmitting apparatus determining a pre-processing base matrix and extending a pre-processing base matrix to obtain an extended pre-processing matrix;

The transmitting apparatus preprocesses the first reference signal with the pre-processing basic matrix and transmits the pre-processed first reference signal to the receiving apparatus; And

The transmitting apparatus performs symbol mapping and spatial modulation on the bit stream to be transmitted, preprocesses the symbols obtained after spatial modulation with the extended pre-processing matrix, and transmits the preprocessed symbols to the receiving apparatus after multicarrier modulation .

In one embodiment, determining the pre-processing base matrix may comprise calculating a pre-processing base matrix according to channel state information, using a predefined pre-processing base matrix, or using predefined codes And a step of selecting a pre-processing basic matrix from the book.

In one embodiment, calculating the pre-processing base matrix according to channel state information includes calculating a pre-processing base matrix according to a channel coefficient matrix using a precoding algorithm; The precoding algorithm includes at least one of a matched filter algorithm, a zero-forcing algorithm, and a least mean squared error precoding algorithm.

In one embodiment, the channel coefficient matrix includes multi-carrier modulation, an equivalent physical-channel coefficient between the transmitter and the receiver, and an equivalent frequency-domain channel coefficient consisting of multi-carrier demodulation.

In one embodiment, extending the pre-processing base matrix to obtain an extended pre-

Performing a linear combination on a column of the preprocessing basic matrix to obtain a column of the extended preprocessing matrix;

Performing a phase rotation on a column of a pre-processing basic matrix to obtain a column of an extended pre-processing matrix, wherein the rotated phases of the different elements of each column are the same or different; And

And multiplying a power allocation factor by a column of the pre-processing basic matrix to obtain a column of the extended pre-processing matrix.

In one embodiment, the number of rows in the preprocessing matrix is equal to the number of transmit antennas, and the number of columns in the preprocessing matrix is used to transmit the channel state information fed back by the receiving apparatus and the number of available reference signals or reference signals And is determined by the transmitting apparatus according to the amount of available resources.

In one embodiment, the number of rows of the extended pre-processing matrix is equal to the number of rows of the pre-processing basic matrix, and the number of columns of the extended pre-processing matrix is greater than or equal to the number of columns of the pre-processing basic matrix.

In one embodiment, the method further comprises:

Further comprising the step of the transmitting apparatus determining the number of columns of the extended preprocessing matrix according to the information fed back by the receiving apparatus.

In one embodiment, the method further comprises:

The transmitting apparatus preprocesses the second reference signal with an expanded pre-processing matrix, and transmitting the pre-processed second reference signal to the receiving apparatus.

In one embodiment, the first reference signal is used to estimate the base equivalent channel and the second reference signal is used to correct the estimate of the extended equivalent channel.

In one embodiment, the basic equivalent channel is comprised of a pre-processing base matrix, multi-carrier modulation, actual physical channel and multi-carrier demodulation.

In one embodiment, the method further comprises:

Further comprising the step of adjusting the insertion density of the second reference signal in accordance with the channel state information fed back by the receiving device, wherein the adjusting comprises selecting the transmitting device not to insert the second signal, Selecting to insert at a density lower than the number of columns in the matrix, or selecting to insert at a density equal to the number of columns in the pre-processing matrix.

The present disclosure also provides a transmitting apparatus comprising a first pre-processing basic matrix computation module, a first pre-processing matrix expansion module, a first reference signal transmission module and a first data transmission module,

The first pre-processing basic matrix calculation module is set to determine a pre-processing basic matrix;

The first pre-processing matrix expansion module is set to extend the pre-processing basic matrix to obtain an extended pre-processing matrix;

Wherein the first reference signal transmission module is configured to perform preprocessing on the first reference signal with a pre-processing base matrix and to transmit the pre-processed first reference signal to the receiving device;

The first data transmission module performs symbol mapping and spatial modulation on the bitstream to be transmitted, performs spatial modulation on the expanded bitstream, performs preprocessing on the symbols obtained, and preprocesses the multicarrier- As shown in FIG.

The present disclosure also provides a signal transmission method based on multi-carrier spatial modulation in a multi-user system,

The transmitting apparatus selecting a pre-processing basic matrix for each terminal according to channel state information and extending a pre-processing basic matrix of each terminal to obtain a corresponding extended pre-processing matrix;

Processing a reference signal with a respective pre-processing base matrix and transmitting a pre-processed reference signal to a corresponding terminal, wherein the reference signal transmitted to the different terminal uses orthogonal resources, ;

Performing a symbol mapping and a spatial modulation on a bit stream of each terminal and performing a pre-processing on a symbol obtained after spatial modulation of each terminal with a corresponding extended pre-processing matrix; And

And the transmitting apparatus combines the preprocessed symbols of each terminal and transmits the combined symbols after multi-carrier modulation.

In one embodiment, the terminals are simultaneously receiving and using the same time-frequency resources.

In one embodiment, the step of the transmitting apparatus selecting the pre-processing basic matrix for each terminal according to the channel state information includes the steps of the transmitting apparatus calculating the pre-processing basic matrix according to the channel coefficient matrix, And selecting a pre-processing basic matrix from a pre-defined codebook according to the state information.

In one embodiment, the channel coefficient matrix includes multi-carrier modulation, an actual physical channel between the transmitting device and all terminals, and an equivalent frequency-domain channel coefficient consisting of multi-carrier demodulation of each terminal.

In one embodiment, combining comprises adding a symbol to be transmitted on the same link.

The present disclosure is also applicable to a multi-user system based on multi-carrier spatial modulation and includes a transmitter including a second pre-processing basic matrix calculation module, a second pre-processing matrix extension module, a second reference signal transmission module, ≪ / RTI > here,

The second pre-processing basic matrix calculation module is set to select a pre-processing basic matrix for each terminal according to channel state information;

The second pre-processing matrix expansion module is set to extend the pre-processing basic matrix of each terminal to obtain a corresponding extended pre-processing matrix;

The second reference signal transmission module is configured to perform preprocessing on the reference signal with each pre-processing basic matrix and transmit the preprocessed reference signal to the corresponding terminal, and the reference signal transmitted to the different terminal uses orthogonal resources;

The second data transmission module performs symbol mapping and spatial modulation on the bit stream of each terminal, performs spatial modulation on the corresponding extended pre-processing matrix, performs preprocessing on the obtained symbols, and preprocesses symbols of the terminal , And transmits the combined symbols after multicarrier modulation.

The present disclosure also provides a method of signal reception based on multi-carrier spatial modulation,

Receiving a first reference signal and estimating a basic equivalent channel based on the first reference signal;

Extending the estimate of the base equivalent channel using a method consistent with the manner used by the transmitting apparatus to extend the pre-processing base matrix so that the receiving apparatus obtains an estimate of the extended equivalent channel; And

The receiving device receives the data and demodulates the received data according to an estimate of the extended equivalent channel to obtain the original data.

In one embodiment, the method further comprises:

Further comprising the receiving device receiving the second reference signal and correcting the estimate of the extended equivalent channel according to the second reference signal.

The present disclosure also provides a receiving device comprising a receiving module, a basic equivalent channel estimating module, an extended equivalent channel estimating module and a demodulation module; here,

The receiving module is set to receive a first reference signal and data;

The basic equivalent channel estimation module is set to estimate a basic equivalent channel based on a first reference signal;

The extended equivalent channel estimation module is set to extend the basic equivalent channel using a manner consistent with that used by the transmitting device to extend the pre-processing base matrix to obtain an estimate of the extended equivalent channel;

The demodulation module is configured to demodulate the data according to an estimate of the extended equivalent channel to obtain the original data.

In one embodiment, the receiving module is further configured to receive a second reference signal;

The extended equivalent channel estimation module is further configured to correct the estimate of the extended equivalent channel in accordance with the second reference signal.

The present invention provides a method and a device for using multiple antennas to provide a layered service for a user receiving a broadcast service. By adopting the present invention, a user with a better channel condition can receive more data or receive more reliable data, and a user with a poor channel condition can also obtain a basic service, so that the channel quality with the worst service quality It is possible to avoid the problem of the conventional broadcast service determined by the user of the mobile station and thus to provide a differentiated service to users of different channel conditions.

On the other hand, by performing spatial modulation through an equivalent channel consisting of preprocessing, multicarrier modulation, real physical channel and multicarrier demodulation, link reliability can be effectively increased and the ability of a multi-carrier spatial modulation system for fading or correlated channels .

1 is a block diagram of a conventional multi-carrier spatial modulation system.
2 is a schematic diagram of a conventional MBSFN system.
Figure 3 is a schematic diagram of one possible way of link grouping in a first embodiment of the present invention.
4 is a schematic diagram of bit grouping in a first embodiment of the present invention.
5 is a schematic diagram comparing bit error rate performance of different groups when four receive links are mounted on the receive side in a first embodiment of the present invention;
6 is a schematic diagram comparing bit error rate performance of different groups when two links are mounted on the receive side in the first embodiment of the present invention.
Figure 7 is a schematic diagram comparing the performance of different groups of bit error rates when two links are mounted on the receiving side and there is a high correlation between links in the first embodiment of the present invention;
8 is a schematic diagram of a data layering method in a first embodiment of the present invention.
9 is a schematic diagram of power allocation between links in a second embodiment of the present invention.
10 is a schematic diagram of the operational flow of a multi-carrier spatial modulation technique supporting layered transmission used in a third embodiment of the present invention.
11 is a schematic diagram of a method of transmitting link number information and link grouping setting information in a third embodiment of the present invention.
FIG. 12 is a schematic diagram showing the link number information carried by the CRC mask method in the third embodiment of the present invention. FIG.
13 is an exemplary diagram of grouped transmissions of RSs in a fourth embodiment of the present invention.
14 is a schematic diagram of resource allocation of a grouped transmission in a fourth embodiment of the present invention.
15 is a schematic diagram of grouping users in a fifth embodiment of the present invention.
16 is a schematic diagram of a process for grouping users in a fifth embodiment of the present invention.
17 is a schematic diagram of a multi-carrier spatial modulation technique process based on layered transmission in a fifth embodiment of the present invention.
18 is a schematic diagram of the structure of one preferred transmitter of the present invention.
Figure 19 is a schematic diagram of the structure of one preferred receiver of the present invention
20 is a schematic diagram illustrating a pre-processing based multi-carrier spatial modulation system in accordance with a first embodiment of the present disclosure;
21 is a flowchart showing a signal processing procedure of the TDD mode according to the first embodiment of the present disclosure.
Figure 22 is a diagram comparing the bit error rate performance of a proposed solution with a conventional solution with a spectral efficiency of 6 bps / Hz according to a second embodiment of the present disclosure;
Figure 23 is a diagram comparing the bit error rate performance of a proposed solution with a conventional solution and spectral efficiency of 4 bps / Hz according to a second embodiment of the present disclosure;
24 is a schematic diagram illustrating a multi-user MIMO system based on preprocessed spatial modulation in accordance with a third embodiment of the present disclosure;
25 is a flowchart illustrating a signal processing procedure based on a pre-processing basic matrix fixed according to the fourth embodiment of the present disclosure.
26 is a schematic diagram illustrating a comparison of bit error rate performance of different solutions with a spectral efficiency of 6 bps / Hz according to a fourth embodiment of the present disclosure;
27 is a schematic diagram illustrating a comparison of bit error rate performance of different solutions with a spectral efficiency of 4 bps / Hz according to the fourth embodiment of the present disclosure;
28 is a schematic diagram illustrating the generation of a preprocessing matrix with adaptive parameter selection in accordance with a fifth embodiment of the present disclosure;
29 is a flowchart illustrating a reference signal insertion and channel estimation procedure according to the fifth embodiment of the present disclosure.
30 is a schematic diagram showing a comparison between constellation with preprocessing and constellation without preprocessing at the receiving end according to the sixth embodiment of the present disclosure;
31 is a schematic diagram showing a comparison of the bit error rate performance of the proposed solution and the conventional solution when the transmitter has four antennas according to the sixth embodiment of the present disclosure;
32 is a schematic diagram showing a comparison between constellation with preprocessing and constellation without preprocessing at the receiving end according to the sixth embodiment of the present disclosure;
33 is a schematic diagram showing a comparison of the bit error rate performance of the proposed solution with the conventional solution when the transmitting end has 16 antennas according to the sixth embodiment of the present disclosure;
34 is a schematic view showing the structure of a transmitting apparatus according to the embodiment of the present disclosure;
35 is a schematic view showing another structure of a transmitting apparatus according to the embodiment of the present disclosure;
36 is a schematic diagram showing a structure of a receiving apparatus according to an embodiment of the present disclosure;

BRIEF DESCRIPTION OF THE DRAWINGS For a more complete understanding of the objects, technical solutions and advantages of the present application, reference is now made to the accompanying drawings, illustrating illustrative embodiments, and further details of the disclosure.

Spatial modulation techniques use antenna indexes to transmit data as additional carriers for information. Compared to a single antenna system, it can achieve higher spectral efficiency with the same bandwidth. However, compared with the conventional multi-antenna system, the space modulation technique has the following advantages. 1. Since only one of the multiple antennas is used in all data transmissions, no synchronization between the antennas is needed on the receiving side; 2. The use of only one antenna can not cause link-to-link interference, and therefore the receiving side does not need an equalization algorithm with higher complexity to eliminate inter-link interference; 3. The need for only a few RF channels can significantly reduce the high energy consumption problems caused by multiple RF channels, that is, spatial modulation is a system with high energy efficiency; 4. The spatial modulation system may still be operational when the number of antennas on the transmitting side is greater than the number of receiving antennas. In addition, spatial modulation can make system parameters more flexible since the same spectral efficiency can be implemented by a combination of different numbers of antennas and modulation methods. A spatial modulation system combined with a multi-carrier technique such as Orthogonal Frequency Division Multiplexing (OFDM) performs spatial modulation on a frequency domain equivalent multi-antenna channel including multi-carrier modulation, actual physical channel, and multi-carrier demodulation do. Although they lose the advantage of having fewer RF channels, they gain greater freedom, especially for problems such as resource allocation, pilot frequency allocation, and are also more compatible with standards.

A block diagram of a multi-carrier spatial modulation technique is shown in the dashed box on the left hand side of Fig. 1, where the number of antennas at the transmit side is set to N and the modulation order used is Q = ^2B , where B is mapped to a symbol The number of bits. The basic process of this is as follows: In the transmitted data stream, a plurality of log ₂ (NQ) = log ₂ (N) + B bits exist as a group, and the first log ₂ (N) The data flow index used is determined, and the next B bits are mapped to one QAM symbol. Taking N = 2 and B = 2 as an example, the spatial modulation bit to symbol mapping relationship is shown in Table 1, where the antenna index represents the current antenna index for the transmitted data. In the sequence of transmitted bits, the first bit is used to determine the antenna index and the next two bits are used to determine the symbol to be transmitted. After the spatially modulated symbol is obtained, an Inverse Fast Fourier Transform (IFFT) is performed to obtain the data flow transmitted on all N transmit antennas for all N data streams.

[Table 1]

Table 1: Bit-to-Symbol Mapping Relationships

A block diagram of the reception side of a space modulation technique employing OFDM technology is shown in Fig. 1 as a dotted box on the right side, and M antennas are mounted on the reception side. Upon receipt of the received signal, the Fast Fourier Transform (FFT) at the receiving end can be performed so that the data flow of each receive antenna is obtained to obtain a frequency domain signal. Assuming a frequency domain equivalent channel matrix, including a transmitting IFFT, an actual physical channel, and a receiving FFT, H? C ^MxN , each channel model can be written as:

y = Hx + n

Where H is the frequency domain equivalent channel matrix represented by an M x N dimensional complex matrix, M is the number of equivalent receive links, N is the number of equivalent transmit links, C ^MxN is the receive vector after the FFT and x = e _i s _j ∈ C ^Nx1 is the transmitted spatial modulation symbol vector, and n ∈ C ^Mx1 is the noise vector. Vector _{e i = [0, ...,} 0,1,0, ..., 0] , and only the i-th element of ^T ∈C ^Nx1 is 1 and the others are 0, which only the i-th antenna in accordance with the transmission bit Is used for data transmission, and [] ^T represents the transpose of the vector. The symbol s _j is a symbol selected from a symbol set of a constellation mapping, for example, QAM (Quadrature Amplitude Modulation), PAM (Pulse Amplitude Modulation), or PSK (Phase Shift Keying) according to a transmission bit. Thus, the received symbols can be abbreviated as follows:

y = h _i s _j + n

Where h _i ∈ C ^Mx1 is the ith column of the matrix H.

On the receiving side, the following maximum likelihood detection algorithm is used to detect transmitted symbols:

의 추정과 수신 심볼

의 추정치를 획득한 후, 비트 대 심볼 매핑 기준에 따라 송신 비트 흐름의 추정 값이 획득될 수 있다.Transmit antenna index

Lt; RTI ID = 0.0 >

The estimated value of the transmitted bit stream can be obtained according to the bit-to-symbol mapping criterion.

In addition to the above-mentioned spatial modulation system with only one data transmission link at a time, a GSM (Generalized Spatial Modulation) system activates a subset of all links in each transmission and uses the index of the subset as a carrier But the different links transmit the same data to improve the reliability of the system; Different data can be transmitted to improve the data rate of the system. This is regarded as one form of spatial modulation in the present disclosure.

The prior art publication [Bit Error Probability of SM-MIMO Over Generalized Fading Channels] and simulation results show that compared to conventional open loop MIMO systems (e.g., Space Frequency Block Coding (SFBC) or V-BLAST systems) Multi-carrier spatial modulation systems can better search for the receive diversity provided by the receive antennas, thus achieving far better performance than conventional open loop systems for users with multiple receive antennas. The characteristics of a spatial modulation system that does not require channel feedback make this technique particularly suitable for a broadcast channel, for example, a PMCH (Physical Multicast Channel) that provides Multi-media Broadcast / Multicast Service (MBMS).

In the existing LTE-A, the MBMS service is provided in the form of a MBSFN (Multimedia Broadcast Single Frequency Network) as shown in FIG. In the figure, a plurality of base stations simultaneously transmit the same broadcast information of the same frequency and use signals from different base stations as multipath components, which obtains a signal-interference plus noise ratio (SINR) So it is well suited to users at the edge of a cell as well as a moving user.

In addition to the difficulty of using the channel state information of the transmitter in the broadcast channel, diversity characteristics of users simultaneously served make it difficult to apply the conventional MIMO technique, and the existing standard PMCH (physical layer multicast channel) Transmits using only a single antenna. In this case, a multi-carrier spatial modulation technique that does not require channel state information feedback can utilize multiple antennas on the base station side as well as provide higher data rates than transmission of a single antenna. By combining MBSFN, higher reliability than single cell multi-carrier spatial modulation can be obtained. Therefore, there is a high possibility of applying spatial modulation techniques to the PMCH.

In current MBMS transmissions, the transmission mode can only be designed for the worst channel, so it is difficult for the user to obtain a better data rate in good channel conditions, limiting the overall system performance available. In the present application, by combining the characteristics of multi-carrier spatial modulation techniques, different quality services will be provided to users in different channel conditions by improving the user experience and improving the overall system performance of the broadcast channel. The basic idea of the present application is to layer the links using the correlation between the links so that the data transmitted in the different layers can obtain different protection. When the receiver detects the data, it will select the detected data layer according to its channel condition. Thus, a user with a poor channel condition can still obtain basic data, but a user with a good channel condition will be able to detect more data layers and obtain higher data rates.

First Embodiment:

This embodiment introduces a multi-carrier spatial modulation system that provides layered transmission in combination with specific system parameter settings. Assuming that the base station is equipped with 16 transmit antennas, that is, up to 16 links can be active at the same time. The available time-frequency resources use the PRB (Physical Resource Block) specified in LTE as one unit, and one PRB consists of 12 subcarriers in 14 adjacent OFDM symbols. The number of system subcarriers is 256 and the number of available subcarriers is 120, that is, consecutive 10 subcarriers in the frequency domain are considered. Space Shift Keying (SSK) modulation is used in this embodiment, that is, one link is activated for each transmission, but each active link Does not transmit a QAM signal but instead transmits a known signal to both the transmitting side and the receiving side. The channel model is as follows:

는 평탄 페이딩(flat fading) MIMO 행렬이며, 즉, 이의 요소는 평균값이 0이고, 분산(variance)이 1인 독립적인 복소 가우시안 분포를 따른다. 는 송신 측 공간 상관 행렬이며, 이는 송신 측에서 링크 사이의 상관 관계(링크 간 상관 관계)를 측정하기 위해 사용된다. 행렬 R_T의 요소는 다음과 같이 표현될 수 있다:Where H? C is a frequency domain equivalent channel coefficient matrix,

Is a flat fading MIMO matrix, i.e. its elements follow an independent complex Gaussian distribution with an average value of zero and a variance of one. Is the transmit side spatial correlation matrix, which is used to measure the correlation (link-to-link correlation) between links at the transmitting end. The elements of the matrix R _T can be expressed as:

Element represents the correlation between the m-th link and the n-th link, d _{m, n} is the distance between the m th link and the n th link, d _min is the minimum distance between the links, , () * Denotes a conjugate.

The layered data transmission service is provided in the form of link layering and grouping. A preferred link grouping criterion is the correlation between the links as shown in FIG. In Figure 3, all links are divided into N groups according to the correlation between the links labeled as group 1, group 2, ..., group N, respectively. It is assumed here that the spatial modulation system activates only one link. Indicates an active link after grouping uses the b ~ b _{1 n,} "inter-group (inter-group)" refers to any group that contains an active link represented bits and; &Quot; Intra-group " means any particular position within the group to which the active link represented by the bit belongs. In this form of grouping, links with stronger correlation (i.e., correlation indexes greater than the set threshold) are arranged in one group, and links belonging to different groups have a relatively low correlation. On the other hand, the upper bits of the transmit bit group are used to indicate which group the activated link is in, while the lower bits are used to indicate the activated link in the group (i.e., some link in the group is activated). The method of grouping can be nested, i.e., the intra-group can continue to perform grouping according to the correlation, thereby achieving the object of multi-layered data transmission It should be noted.

In this embodiment, SSK modulation with 16 available links can transmit 4 bits of information in each communication, and all links are grouped into three layers. First, for the first layer of the group, the first eight links are grouped as one group, the latter eight links are grouped as one group, the most significant bit indicates which group the link is activated on; Next, each link group is divided into two groups according to a correlation, each group including four links having a higher correlation as a second layer of the group, and the second most significant bit is indicative indication; Finally, the last two least significant bits are used to indicate which of the four links in the group is active as the third layer of the group. Figure 4 shows a schematic diagram of bit grouping in this embodiment. As shown in FIG. 4, in the 4-bit information, b ₁ is a bit representing the first layer of the group, b ₂ is a bit representing the second layer of the group, and b ₃ and b ₄ are the third layer Lt; / RTI >

First, consider the case where four links are mounted on the receiving side and the channel correlation coefficient ρ = 0.1. Figure 5 shows the bit error rates that can be obtained by different groups in this case. Here, the legacy 'first layer' represents the bit error rate of the first layer of the group, the most significant bit; 'Second layer' represents the bit error rate of the group of the second layer, i.e. the second most significant bit; The 'third layer' represents the bit error rate of the third layer of the group, the least significant two bits; 'Average' represents the average bit error rate. In this case, it can be seen that the first layer of the group has the best bit error performance, but the third layer of the group has the worst performance. Under the same bit error rate, the performance of the first layer of the group is about 2 dB better than the performance of the second layer of the group, and is about 4 dB better than the performance of the third layer of the group. Thus, for a user with a good channel condition and a higher signal-to-noise ratio on the receiving side, all three layers of data can be decoded, but for a user with a lower signal-to-noise ratio, Only the first layer of < / RTI >

Next, consider the case where two links are mounted on the receiving side and the channel correlation coefficient ρ is 0.3. Figure 6 shows the bit error rates that can be obtained by different groups in this case. Here, the legacy 'first layer' represents the bit error rate of the first layer of the group, the most significant bit; 'Second layer' represents the bit error rate of the second layer of the group, i.e., the second most significant bit; The 'third layer' represents the bit error rate of the third layer of the group, the least significant two bits; 'Average' represents the average bit error rate. As with the results of FIG. 5, in this case, the different groups may still obtain significant performance differences, so that the user can select an appropriate data rate according to his channel condition.

Finally, consider the case where two links are mounted on the receiving side and the channel correlation coefficient ρ = 0.5. Figure 7 shows the bit error rates that may be obtained by different groups if the link has a high correlation. Here, the legacy 'first layer' represents the bit error rate of the first layer of the group, the most significant bit; 'Second layer' represents the bit error rate of the second layer of the group, the second most significant bit; The 'third layer' represents the bit error rate of the third layer, or least significant bit, of the group; 'Average' represents the total bit error rate. In this case, the performance gap between the different layers is much clearer. For example, when the bit error rate is 10 ^-3 , the performance of the first layer of data is about 5 dB better than the performance of the second layer of data and about 8 dB better than the performance of the third layer of data.

The simulation results from Figures 5 to 7 show that the way in which the layered data is transmitted using correlation between links is more effective when there are multiple antennas mounted at the receiver or there is a specific correlation between the links ; It is possible to provide differentiated services to users having different signal-to-noise ratios while ensuring that users can obtain basic services.

The above-described results illustrate that the link grouping method provided by the embodiment can provide different bit error rate performance between different groups, thus facilitating the system to transmit different data for different groups. One possible method is to transmit the most basic information about the bits of the first layer of the group and the bits of each subsequent layer of the group carry the extended information based on this layer of data. For example, the extension information may be additional service data for the base service, and may also be data that improves time-frequency definition or voice clarity. Thus, each time a layer of data is decoded, the data rate can be improved based on the data of the previous layer. Another possible way is to transmit the most basic information for the bits of the first layer of the group, and the bits of each subsequent layer of the group (such as parity bits for channel encoding or repetition of information in the first layer of the group) And transmits duplicate information. Thus, each time a layer of data is decoded, reliability can be improved based on data in the previous layer, thereby improving the robustness of the system. To improve both data rate and reliability, the two methods described above can be combined.

In order to make it easier for the receiver to detect the data of each layer, data of each layer can be divided into blocks, and independent CRC check codes can be added. While this may slightly reduce the data rate, it may make it easier for the user to perform layered data detection. Figure 8 shows a schematic diagram of this data layering method. In the figure, the first layer of data is basic data and the other layer of data is an extension or redundancy based on the first layer of data. The example shown in the figure divides each layer of data into data blocks 1 and 2 and adds CRC check codes independent of each other to data block 1 and data block 2, respectively.

In the channel of this embodiment, the links are grouped according to the correlation between the links. In the channel model used, since closer links have a higher correlation, in this embodiment, grouping can be performed directly according to the order of the links. Since most systems use dual polarized antennas where different groups of polarized antennas can be considered independent of each other, the first layer of the group can be determined by using the polarization direction between different antennas. Since it is taken into account that adjacent antennas tend to have a higher correlation, grouping according to distance between antennas having the same polarization direction is also reliable. In addition, channel state information from user feedback may also be used to determine which links are more correlated, and grouping of links may be performed in accordance with such information.

Although the simulations presented in this embodiment do not take into account the case of transmission of constellation point symbols such as QAM symbols or PSK symbols in an actual system, some of the information may also be conveyed to constellation point symbols for transmission. Most detection algorithms with low complexity actually used assume that it is necessary to detect the used link first and then perform the subsequent constellation point symbol detection after determining the active link on the transmitting side. Thus, if a link detection error occurs or link detection has a higher uncertainty, this will have a serious negative impact on the detection of the constellation point symbol. In this case, the constellation point symbol may be treated as data whose priority or importance is one layer lower for transmission. Another way to transmit constellation point symbols is to use a constellation point symbol to transmit a separate data flow and to determine whether to maintain the data flow by CRC detection. In some special situations, such as when there is a stronger correlation link such as a stronger direct mapping path, link detection may not be accurate but still can guarantee the accuracy of the constellation point symbol. In this case, instead of sending a separate data flow using the constellation point symbol, the throughput may be improved instead. At this point, the data flow sent to the constellation point symbol may include some auxiliary data For example, redundancy or redundancy of some hierarchy of data, or some new ancillary data information.

Second Embodiment:

The present embodiment will provide a multi-carrier spatial modulation technique that supports pre-processed layered transmissions on the transmit side. In some real systems, due to the fact that feedback is absent or feedback is not ideal, the link grouping setting of the base station may not guarantee that it meets the requirements of all users. At this point, the difference between the different groups can be increased at the base station side by preprocessing the different links, thereby increasing the likelihood of accurate detection.

The preprocessing in this embodiment includes, but is not limited to, power allocation and phase rotation. Both preprocessing methods will be described below.

1. Power allocation.

Assuming that the average transmit power is not changed, the average transmit power of each group of the first layer is adjusted such that different groups have different average transmit power; Assuming that the average transmit power of each group of the first layer is not changed, the average transmit power of each group of the second layer is adjusted such that different groups of the second layer have different average transmit power; The above-described procedure is performed recursively according to the above-described steps, and finally, the power allocation results for each of the groups in each hierarchy are obtained. To ensure that detection of the previous layer is not affected by power adjustment of the next layer, the power adjustment amount of the previous layer needs to be specified to be strictly higher than the power adjustment amount of the next layer. An example of the power allocation between links is shown in FIG.

Figure 9 shows a grouping setup in which the number of links available to the base station is 4 and two layers are used for transmission. Each group of the first layer comprising two links; Each group of the second layer includes one link. Assuming that the average transmission power is 1, the average power of the two groups of the first layer is adjusted, assuming that the average transmission power is not changed. For example, as shown in FIG. 9, the average power of group 1 of the first hierarchy is adjusted to 1 + p, and the average power of group 2 of the first hierarchy is adjusted to 1-p. Assuming that the average power of each group of the first layer is not changed, the power of each group of the second layer is adjusted. For example, the average power of each group of the second layer is adjusted to 1 + p + p ₁ , 1 + pp ₁ , 1-p + p ₁ , 1-pp ₁ . In order for the group of detection of the first layer, to ensure not to be affected by the power allocation of the second layer it is necessary to check if p> p _1.

2. Phase rotation.

Except for power adjustment between different links, the difference between different groups can be increased through phase rotation. One possible criterion for phase rotation is to randomly select the rotational phase for the link of each group of the lowest layer, where the randomly selected phase intervals do not intersect for each group, Are selected for links belonging to the same group. Since the number of groups in the lowest layer is 4, the system shown in Fig. 9 is still used as an example in which the number of links is 4 and the number of layers is 2. Thus, four phase intervals are selected as phase rotation intervals. Group 1 of the second hierarchy belongs to the same group of the first hierarchy (i.e., group 1 of the first hierarchy) and group 3 and 4 of the second hierarchy belong to another group of the first hierarchy (i.e., The adjacent rotational phase interval is selected for group 1, 2 of the second hierarchy and another adjacent rotational phase interval is selected for group 3, 4 of the second hierarchy. The rotation phase intervals for the four groups of the second layer are as follows.

[5/8, 3/4], [5/8, 5/8]

It is also noted that the two methods described above can be combined to further increase the distance between different groups, i. E. Power adjustment and phase rotation can be performed simultaneously.

When transmitting the reference signal used for group channel estimation (the reference signal can be used for demodulation of each group), the reference signal passes through the same pre-processing so that the reference signal can be directly applied to the estimation of the pre- Can be used. Moreover, in the case of an actual system based on physical resource block scheduling, each time-frequency resource from the same physical resource block uses the same pre-processing method.

Third Embodiment:

This embodiment will illustrate the operational flow of a multi-carrier spatial modulation technique using layered transmission supported by this solution in an actual system.

10 shows a schematic diagram of the operational flow of a multi-carrier spatial modulation technique supporting layered transmission used by the present embodiment. On the base station side, the user equipment UE is first informed of link number information and link grouping setting information used for data transmission; The data to be transmitted is layered according to information about the number of selected links and link grouping setting information; The reference signal corresponding to the selected link is transmitted and the data to be transmitted is transmitted to the UE after multi-carrier spatial modulation is performed. Here, the number-of-links information may be set in advance or included in the link grouping setting information, and thus the number-of-links information is optional information to be transmitted. In addition, a pattern for link grouping can be set, and the base station can assign a specific link grouping pattern to the UE so that the UE obtains information about the links included in each group as well as the grouping of links.

On the UE side, link number information and link grouping setting information are first obtained. The link channel state information is then estimated by the reference signal of each link or group according to the information. Finally, detection of the data flow is performed to estimate the transmitted data.

The link number information indicates the number of links used for transmitting the space modulated signal. A base station can often support more links because it tends to mount more antennas. However, in view of the different channel conditions and the service user, there is a need to select an appropriate number of links depending on the particular situation. The link grouping setting information refers to the grouping of links after the number of links is selected. For one kind of link number, only one or two link grouping settings need to be specified. For example, when the number of links used by the base station is eight, one possible link setup is to place each of the four links as a first layer into one group, then every two links as a second layer Groups; Or every two links are assigned as one group as the first layer. Specific link grouping settings may also be determined by channel conditions and user settings. With the link number information and the link grouping setting information, the specific grouping setting used by the base station can be determined.

The following is a detailed description of the process described above.

When the base station informs the UE of link number information and link grouping setup information, the information may be transmitted on a physical broadcast channel (PBCH) or a physical downlink control channel (PDCCH). While transmitting on the PBCH, the following two formats may be selected.

1. A new field is added to the PBCH to transmit link number information and link grouping setting information.

As shown in Fig. 11, two fields, i.e., a link number information indication field and a link grouping setting information indication field, are added to the reserved bits of the PBCH (as shown in the additional fields of Fig. 11) .

Since the number of designated antenna ports is 1, 2, or 4 on the PBCH, the user performs detection in the form of blind detection and CRC mask detection, and therefore needs to be notified only when the number of antenna ports is greater than four. For example, when a base station has 128 antennas, the number of links that can be used by multi-carrier spatial modulation is 2, 4, 8, 16, 32, 64 and 128 (i.e., a power of 2). When the number of links used is notified, only when the number of links is larger than 4 is notified. One possible notification method is shown in Table 2.

[Table 2]

Table 2: One possible way to show link count information when the number of links is 128

In Table 2, the 3 bits are used to notify the UE of the number of links for which the last two cases are reserved, which shows that more links can be supported in this manner. In addition, the number of links of the same kind needs to support one or two grouping settings to meet only the layered transmission requirements, so that the two newly added fields need to occupy only four bits. It is assumed that the number of reserved bits is 10 on the PBCH, so that 4 bits of overhead is acceptable.

2. Link number information is transmitted by CRC mask.

A way to inform the user of the number of antenna ports in a conventional PBCH channel is to add a mask corresponding to the number of each antenna port to the CRC check code, which is a transmission mode blind detection plus CRC mask. By adding an available CRC mask, the link number information can be informed to the user without additional fields.

Figure 12 shows a preferred method of carrying link count information using a CRC mask. The transmission mode used by the PBCH includes a single antenna port mode, a dual antenna port antenna diversity mode and a four antenna port antenna diversity mode. To ensure the reliability of the PBCH transmission of information, the available CRC mask may be divided into three groups corresponding to a single antenna port, a dual antenna port and four antenna ports, respectively. In the example shown in FIG. 12, CRC masks 1, 2 and 3 all correspond to a single antenna port. Thus, by decoding one of the masks, the user can determine that the transmission mode used by the PBCH is a single antenna port mode. Each CRC mask in turn represents the number of links used by the actual broadcast channel. For example, if the number of links used by the broadcast channel is set to 16 and the PBCH transmission uses a single antenna port mode, CRC mask 3 is selected to process the CRC check bits. After the user has been informed by the CRC check that Mask 3 is being used, the user can see that the PBCH transmission mode is single antenna port mode and the number of links used by the broadcast channel is 16. When using this method, the user is notified of the link grouping setting information by adding an extra field to the reserved bits.

In addition, these two schemes described above can be combined, i.e., use a CRC mask to notify the number of ports adding extra fields to the reserved bits in the PBCH, thus improving the reliability of the information.

The above-described link number information and link grouping setting information can also be transmitted on the downlink control channel, i.e., adding an extra field to the control channel to indicate link number information and link grouping setting information. One possible method of indicating link number information is shown in Table 2, where bit 000 indicates that the link setting used is the same as the setting of the PBCH.

In addition to these two methods, link number information and link grouping setup information may also be transmitted on the physical downlink shared channel (PDSCH).

The data is layered by the base station according to one or more of the following criteria:

One. Data is layered according to the priority of data, that is, data having the highest priority is allocated to a bit layer having the highest reliability; The data with the second highest priority is assigned to the bit layer with the second highest reliability; With this analogy, data with the lowest priority is assigned to the bit layer with the lowest reliability. Here, the priority may be the priority of the application data, that is, the data with the highest priority requires a more efficient and more reliable decoding, while the data with the lower priority has a higher priority Can be mitigated. The priority can also be a priority of the multimedia data, that is, the data having the high priority is the basic data, and by decoding the data having the high priority, the basic multimedia service can be obtained, By further detection, the quality of service can be improved based on the base service.

2. Alternatively, the bit layer with the highest reliability transmits the basic information bits. After performing the channel encoding on the basic information bits, the redundant information bits are transmitted in the second highest reliability bit layer, and the redundant bits generated from the additional encodings are transmitted in the low reliability bit layer. Thus, once a layer of data is detected, the reliability of the received signal can be improved. Moreover, the two types of layering methods described above can be combined to simultaneously increase the data rate and reliability.

For data detection, the user can use the following two methods.

1. Joint detection. That is, the user performs joint detection for each data layer and obtains an estimated value of the transmitted data of each layer. Then, the received signal-to-noise ratio is estimated for each data layer, and a layered data flow exceeding a certain threshold is selected for further processing (such as channel decoding and source decoding, etc.); If the layered data is processed by adding a block-by-block CRC, a CRC check can be performed for each data layer, and each layer that passes the check is maintained.

2. Detection by hierarchy. That is, until the received signal-to-noise ratio of a layer can not reach a certain threshold value or a layer of CRC check fails to pass, the information transmitted on each data layer depends on the channel status information of each layer It is detected by layer.

Fourth Embodiment:

In this embodiment, a reference signal setting method using the solution provided by the present application will be presented.

The reference signals can be processed according to the insertion method used in conventional communication systems, i.e. the reference signals used for the estimation of the different link channels use resources which are mutually orthogonal for transmission, that is, Domain, time resource, or the same time-frequency resource, but uses mutually orthogonal codes to distinguish between different links. This method can estimate channel state information for each link. Data detection may be performed in a collaborative manner from each group and data from the group in which the confidence has exceeded a certain threshold value is selected for further processing. The channel state information of each group can also be obtained via combination, and then each data layer can be detected through hierarchical detection until the signal of a layer reaches a signal-to-noise ratio threshold .

In this embodiment, a scheme of a group for transmitting a reference signal will be presented. The basic idea is to simplify the design of the receiver by transmitting the group's reference signal, allowing each data layer to be detected directly from the group's channel state information. 13 shows a simple example of a group for transmitting a reference signal with a link number of 8 on the transmitting side and a number of layers of 3. In Fig. 13, the first layer of the group includes two groups, and each group includes four links. To distinguish between the two groups of the first layer, two orthogonal reference signals of length 2 are required as shown in the figure as RS1 and RS2. When transmitting the reference signal of this layer, the four links belonging to the same group transmit the same reference signal data on the premise of power constraints, and the four links belonging to the other group are connected to the reference And transmits the signal data. Each group in the second layer of the group comprising two links; Also, only two reference signals that are orthogonal to each other that are two in length are required to distinguish two different groups. In particular, in Figure 13, Link 1 and Link 2 transmit the same reference signal, i.e. RS3, but Link 5 and Link 6 transmit a reference signal orthogonal to the signal, RS4, and the remaining links are not active. And the channel state information of the other two groups may be calculated in combination with the channel state information of the first layer group. When transmitting the channel state information of the third layer of the group, four orthogonal reference signals of length 4 are used as RS5 to RS8, that is, only channel state information of links 1, 3, 5, and 7 need to be estimated The channel state information of the remaining links can be obtained in combination with the channel state information of the second layer.

The group method of transmitting the reference signal described above can simplify the operation of the user without consuming additional resources, so that a user with a poor channel condition can decode the basic data faster.

14 shows a schematic diagram of time-frequency resource allocation for a group transmitting a reference signal. For the example shown in FIG. 13, the conventional scheme of the reference signal transmission requires eight orthogonal reference signals and therefore requires eight orthogonal time-frequency resources. From the above description, layer 1 requires two orthogonal reference signals and thus requires two orthogonal time-frequency resources; Layer 2 requires two orthogonal reference signals and thus requires two orthogonal time-frequency resources; Layer 3 requires four orthogonal reference signals and therefore requires four orthogonal time-frequency resources. Therefore, the time-frequency resources required by the present invention are the same as those of the conventional method, but the present invention can support better layer-by-layer detection and is more advantageous for users with poor channel conditions.

Fifth Embodiment:

In this embodiment, a solution is presented that determines link grouping settings and user group settings based on channel state information from user feedback.

Although the multimedia broadcast / multicast service in LTE-A does not support coordinating the process at the sender according to the feedback information of the user, for the solution proposed by the present application, Adjusting the number of links and link grouping settings may provide better service for users at different channel conditions. On the other hand, the feedback-based solution may also be suitable for users with services in open-loop mode. 15, the base station assigns users having the same or similar information as the number of links and the information of the link grouping to a group, and transmits the same time-frequency Perform broadcast services on resources.

The specific grouping process is illustrated in FIG. On the base station side, a downlink reference signal is transmitted to measure the channel state information of the downlink physical channel. The reference signal may be similar to a cell-specific reference signal (CRS) or a channel state information reference signal (CSI-RS) in LTE / LTE-A. The reference signal plays a role different from the reference signal described in the second embodiment. The UE estimates the downlink channel based on the reference signal, and feeds back the estimated channel state information to the base station. The base station estimates the correlation between the links according to the feedback from the UE, determines the link grouping setting of the user, assigns users having the same or similar link grouping setting as one group, And performs a broadcast service for the same time-frequency resource.

To measure the correlation between the links, the base station also estimates uplink channel state information according to SRS (Sounding Reference Signal) transmitted from the UE to the base station over the uplink channel to estimate the correlation between the downlinks . For a time-division duplex (TDD) system, using the reciprocity between the uplink and downlink channels, the correlation between the downlinks can be obtained directly. For a frequency division duplex (FDD) system, the correlation between the links is also determined by the uplink channel estimation, since the correlation between the links is affected and determined by the large fading between the channels. .

The user can feed back channel state information through RI (Rank Indication) and PMI (Precoding Matrix Index) existing in LTE. The base station estimates the correlation between the downlinks according to the feedback of the user. For convenience of user feedback, a link grouping setup pattern codebook known to both the base station and the user can also be designed, and the user feeds back link number information via the RI and feeds back the necessary link grouping settings via the link grouping setup pattern .

Through the estimation of the correlation between user links, the base station can dynamically adjust the user group and notify the user of the time-frequency resource location where broadcast data is needed on the downlink control channel or downlink shared channel. The user reads the information on the downlink control channel or the downlink shared channel, and obtains information on the number of used links and link grouping configuration information as well as broadcast data resource allocation information. Based on this information, the user obtains the broadcast data from each source.

The signal processing flow of a multi-carrier spatial modulation system based on group transmission, including user grouping, preprocessing, is shown in Fig. User grouping and link establishment selection based on feedback / uplink transmission is an optional part. The structure shown in Fig. 17 is suitable not only for control channel transmission but also for providing a multimedia broadcast / multicast service broadcast channel. When applying such a structure to a control channel, the basic data includes some control information required for the system, and the extended data may be some extended control data for increasing the transmission data rate of the control channel, or may increase the reliability of the control channel Or duplicate of the underlying data to make it; This can also be used for receivers working in open loop mode, and receivers in this kind of mode can not efficiently feed back channel state information. With the solution provided by the present application, the receiver can voluntarily adjust the rate at which it receives data according to changes in channel conditions, thus providing greater flexibility and reliability.

Corresponding to the method described above, the present application provides a transmitter, the structure of which is shown in Fig. The transmitter,

A setting module for transmitting link grouping setting information, wherein the link grouping setting information divides a link into at least two groups, and thereafter, information of a link included in each of the groups. The setting module;

A data layering module for layering a data flow transmitted according to a group of links;

A spatial modulation module for performing spatial modulation on the layered data flow;

A multi-carrier modulation module for performing multi-carrier modulation on the spatially modulated signal; And

And a transmitting module for transmitting the multi-carrier modulated signal.

Corresponding to the method described above, the present application also provides a receiver, the structure of which is shown in Fig. The receiver,

A setting information receiving module for receiving the link grouping setting information;

A group acknowledgment module for obtaining link grouping and link information included in each of the groups according to the link grouping setting information; And

And a detection module for performing layered detection on the received data according to the grouping of the links.

Sixth Embodiment:

In this embodiment, a downlink physical channel training solution applicable to multi-carrier spatial modulation is described with reference to exemplary system parameter settings. In this embodiment, the base station has N antennas, and the terminal has M antennas. Such a system operates in a time division duplex (TDD) mode. Thus, the state of the uplink channel can be used for the downlink channel according to the channel correlation.

20 is a schematic diagram illustrating a pre-processing based multi-carrier spatial modulation system in accordance with a first embodiment of the present disclosure; It can be seen from Fig. 20 that, compared with a conventional multi-carrier spatial modulation system, the pre-processing based spatial modulation system provided by this embodiment adds a pre-processing module between the spatial modulation and the IFFT module. The basic idea is to perform spatial modulation operations on the equivalent channel consisting of preprocessing → IFFT → channel → FFT to increase the reliability of the link, reduce the pilot overhead, and support multiple simultaneous serving terminals. In this embodiment, the signal processing procedure in the TDD mode is as shown in Fig. 21 and is briefly described below.

First, the terminal transmits an uplink SRS (Sounding Reference Signal) to the base station. The base station estimates a system frequency domain channel according to the received SRS and obtains a channel coefficient matrix H? C ^MxN constituted by frequency domain channel coefficients.

Then, the base station calculates a pre-processing the base matrix W _b ∈C ^NxM according to a channel coefficient matrix. The preprocessing is performed by MF (Matched-Filter) precoding, i.e. W _b = H ^H , ZF (Zero-Forcing) precoding, i.e. W _b = H ^H (HH ^H ) ^-1 or MMSE But not by way of limitation.

The base station then extends the pre-processing base matrix to obtain the extended pre-processing matrix W? C ^NxN . The preprocessing base matrix can be extended by any one of the following three methods.

가 행렬 W_b의 제 m 열 벡터를 나타내는

이며이면, 행렬 W의 제 n 열 벡터 w_n은

로에 의해 나타내어질 수 있으며, 여기서,

는 w_n을 생성할 때 벡터 W_b에 대한 선형 결합 계수를 나타낸다. 선형 결합 계수는 수신 단에 의해 수신된 심볼 사이의 유클리드 거리(Euclidean distance)를 가능한 한 크게 하기 위해 선택된다(또는 등가 채널 벡터 사이의 유클리드 거리를 가능한 한 크게 한다). 하나의 간단한 조건은 선형 결합 계수가 실수이고, 반대 수가 없다는 것이다. 이러한 조건은 가능한 조건 중 하나일 뿐이다. 심볼 사이의 유클리드 거리를 가능한 한 크게 보장할 수 있는 임의의 조건이 적용 가능하다.First Expansion Method: Performs a linear combination on a column of a pre-processing basic matrix to obtain a linear combination, that is, a column of an extended pre-processing matrix. E.g,

Represents the m-th column vector of the matrix W _b

, The nth column vector w _n of the matrix W is

, Where < RTI ID = 0.0 >

Represents the linear coupling coefficient for the vector W _b when generating w _n . The linear combination factor is chosen to make the Euclidean distance between the symbols received by the receiving end as large as possible (or make the Euclidean distance between equivalent channel vectors as large as possible). One simple condition is that the linear coupling coefficient is a real number and not an inverse number. These conditions are only one of the possible conditions. Any condition that can guarantee the Euclidean distance between symbols as large as possible is applicable.

에 의해 나타내어질 수 있으며, 여기서 벡터

는 전처리 기본 행렬의 제 m 열을 나타내고, j는 허수 단위이고,

는 회전각을 나타낸다. 게다가, 위상 회전은 각각의 열 벡터의 요소에 상이한 회전 인수를 곱하거나, 열 벡터에 N×N 회전 행렬을 곱하는 것과 같은 다양한 방식을 통해 구현될 수 있다.Second Expansion Method: Phase rotation is performed on the column vectors of the preprocessing basic matrix to obtain the phase rotation, i.e., the column vectors of the expanded preprocessing matrix. In particular, the nth column of the expanded preprocessing matrix

, Where the vector < RTI ID = 0.0 >

Represents the m-th column of the pre-processing basic matrix, j is an imaginary unit,

Represents the rotation angle. In addition, phase rotation can be implemented in various ways, such as multiplying elements of each column vector by different rotation factors, or multiplying a column vector by an NxN rotation matrix.

에 의해 나타내어질 수 있으며, 여기서,

는 전력 할당 인수를 나타낸다.Third Expansion Method: Power allocation, that is, each column vector of the pre-processing base matrix is multiplied by the power allocation factor to obtain the column of the extended pre-processing matrix. In particular, the nth column of the expanded preprocessing matrix

, Where < RTI ID = 0.0 >

Represents the power allocation factor.

It should be noted that the above three methods can be used in combination. For example, a linear combination of the columns of the preprocessing basic matrix may be performed first to obtain the NxN matrix, and then a phase rotation and power allocation operation may be performed to obtain the final extended pre-processing matrix on this matrix.

이며, 행렬 W는 특정 규칙에 따라 생성된다. 따라서, 단말기가 규칙을 알고 있으면, 단말기는 채널 추정이 적은 선형 결합의 규칙에 따라 완전한 채널 행렬을 생성할 수 있다. 특히 기본 등가 채널은 다음에 의해 정의된다:Finally, when transmitting data to the terminal, the base station needs to perform downlink equivalent channel training. The equivalent channel experienced by the data transmitted by the base station is

, And a matrix W is generated according to a specific rule. Thus, if the terminal knows the rules, the terminal can generate a complete channel matrix according to the rules of linear combination with fewer channel estimates. In particular, the basic equivalent channel is defined by:

은 다음에 의해 나타내어진다:On the other hand,

Is represented by: < RTI ID = 0.0 >

로 수행되면, 등가 채널

의 추정이 획득될 수 있다는 것을 알 수 있다. 이것은 다운링크 등가 채널을 추정할 때, 기본 등가 채널

을 추정하기 위해서만 필요로 되고, 등가 채널

의 추정은 필요로 되지 않는다는 것을 의미한다. 따라서, 다운링크 채널 추정에 대한 오버헤드가 효과적으로 감소된다.The expansion operation, which corresponds to creating the preprocessing matrix,

, The equivalent channel

≪ / RTI > can be obtained. This is because, when estimating the downlink equivalent channel,

Lt; RTI ID = 0.0 > channel < / RTI >

Lt; / RTI > is not required. Thus, the overhead for downlink channel estimation is effectively reduced.

In particular, when performing downlink training, the base station estimates M downlink base equivalent channels, performs preprocessing on the downlink reference signal with the pre-processing base matrix W _b , and transmits the pre-processed downlink reference signal to the terminal It is only necessary to do. After completing the downlink basic equivalent channel training, the base station performs a pre-processing on the downlink data using the matrix W.

During downlink equivalent channel training, the signal received by the terminal may be represented by:

Y _P = HW _b P + N;

는 기준 신호 행렬을 나타내며, M_P는 기준 신호의 길이를 나타낸다. 예를 들어, M_P=M, 행렬 P는 단위 행렬이고, 즉 기준 신호는 직교 시간-주파수 자원 상에서 송신된다. 단말기는 기준 신호 행렬 P를 알고 있기 때문에, 단말기는 기본 등가 채널

의 추정치

를 획득할 수 있다. 한편, 단말기는 전처리 기본 행렬로부터 확장된 전처리 행렬을 생성하기 위한 확장 규칙을 이미 알고 있으므로, 단말기는 전처리 기본 행렬을 확장할 때 송신단과 동일한 방식을 사용하여 확장된 등가 채널 행렬

의 추정치

를 복원할 수 있다. 데이터가 송신될 때, 단말기에 의해 수신된 신호는 다음에 의해 나타내어질 수 있다:here,

Represents the reference signal matrix, and M _P represents the length of the reference signal. For example, M _P = M, matrix P is a unitary matrix, i.e., the reference signal is transmitted on an orthogonal time-frequency resource. Since the terminal knows the reference signal matrix P,

Estimate of

Can be obtained. Since the terminal already knows an extension rule for generating an extended pre-processing matrix from the pre-processing basic matrix, the terminal uses an extended equivalent channel matrix

Estimate of

Can be restored. When data is transmitted, the signal received by the terminal may be indicated by:

에 따라 송신 신호를 추정하여, 추정된 비트 스트림을 출력한다.Where x? C ^Nx1 represents the transmitted signal after spatial modulation and y? C ^Mx1 represents the signal received by the terminal. The terminal estimates the received signal y and the estimated equivalent channel matrix

And outputs the estimated bit stream.

In this solution, it can be seen that the extended pre-processing matrix is obtained by multiplying the pre-processing base matrix by the expansion matrix, i.e., the expanded pre-processing matrix finally obtained is calculated as:

W = W _b W _e

. 확장된 등가 채널과 기본 등가 채널은

을 충족한다. 따라서, 수신단이 확장 행렬 W_e을 알고 있다면, 이는 기본 등가 채널의 추정에 기초하여 확장된 등가 채널을 복원할 수 있다. 이 때, 다운링크 기준 신호의 오버헤드는 기본 등가 채널의 차원과만 관련이 있다. 시스템 스펙트럼 효율에 대한 다운링크 트레이닝의 영향은 크게 감소된다.Here, W _e? C ^MxN represents an expansion matrix and can be designed according to the above-described three expansion methods described in this embodiment. During channel estimation, the basic equivalent channel is first expanded,

. The extended equivalent channel and the default equivalent channel

. Therefore, if the receiving end knows the extension matrix W _e , it can recover the extended equivalent channel based on the estimation of the basic equivalent channel. At this time, the overhead of the downlink reference signal is only related to the dimension of the base equivalent channel. The impact of downlink training on system spectral efficiency is greatly reduced.

Hereinafter, an example for explaining the parameter setting is provided. Assuming that the system is a multi-antenna system with QPSK modulation, N = 16, M = 2. If conventional multi-carrier spatial modulation is used, six bits can be transmitted each time. At the same time, downlink training is required to estimate the total of 16 links, which results in a large burden on the system spectral efficiency. However, according to the solution of the present disclosure, it is only necessary to estimate two basic equivalent channels, which can greatly reduce the overhead of channel training. In this example, a linear combination and phase rotation extension method is used to extend the pre-processing base matrix. The preprocessing base matrix generated by the sender has a dimension of 16x2. A linear combination of the columns of the matrix is performed to obtain an extended intermediate matrix. The linear coupling coefficients are as shown in Table 3.

[Table 3]

[Table 3] Linear Coupling Coefficient

To obtain the final preprocessing matrix, phase rotation is performed on the columns of the middle matrix. All elements of the same column vector use the same phase rotation factor. In this embodiment, two adjacent columns use the same phase rotation factor, e.g., a multiple of 11.25 degrees.

Before the data is transmitted, the reference signal matrix is processed after being processed by the pre-processing base matrix, and then the data is transmitted after spatial modulation and processing based on the extended pre-processing matrix. The receiver estimates the downlink basic equivalent channel according to the reference signal and acquires the extended equivalent channel by expanding the column of the basic equivalent channel matrix according to Table 3 and the phase rotation processing rule. Finally, the terminal obtains the estimated equivalent channel matrix and the estimated bit stream according to the received signal.

It should be noted that the solution of the present disclosure creates an equivalent link between the transmit and receive ends, so that multiple links can be activated simultaneously based on an equivalent link to achieve generalized spatial modulation.

Example 7:

In this embodiment, the validity of the solution of the present disclosure is described with reference to parameter settings in the actual system and the simulated results. Assuming that the system uses 256 subcarriers, the number of valid subcarriers used to transmit data is 120. Consecutive 12 subcarriers of 14 OFDM symbols form a physical resource block (PRB). It is assumed that the transmitting end knows channel state information. According to the channel state information, the base station calculates the pre-processing base matrix according to the matched filter precoding algorithm,

W _b = H ^H.

Thereafter, the base station expands the pre-processing basic matrix according to the extension method described in the first embodiment, and preprocesses the data. The EVA channel model is utilized. The moving speed of the terminal is 50 km / h.

First, it is considered that the base station has 16 antennas and the terminal has two antennas. A QPSK modulation scheme is adopted. In this situation, the spectral efficiency is 6 bps / Hz. The expansion of the pre-processing basic matrix is similar to that of the first embodiment, i.e., performs linear combination and phase rotation on the columns of the pre-processing basic matrix. The linear coupling coefficients are as shown in Table 3. Conventional multi-carrier spatial modulation systems are selected for comparison. The system structure of a conventional multi-carrier spatial modulation system is shown in Fig.

22 is a schematic diagram illustrating a comparison of bit error rate performance of a pre-processing solution of the present disclosure and a conventional solution; The horizontal axis indicates the E _s / N _0, E _S represents the average energy of the transmitted symbols in each time, is normalized to 1 in this embodiment. N ₀ represents the noise spectral density used to evaluate the noise energy. It can be seen that with the preprocessing provided by this disclosure at the same data rate, the bit error rate performance of the multi-carrier spatial modulation system is greatly improved. For example, around a bit error rate of 10 ^-3 using the preprocessing method provided by this disclosure, the system performance is improved by about 7 dB compared to a conventional multi-carrier spatial modulation system.

From the above, it can be seen that the embodiment of the present disclosure first generates an energy concentrated link through preprocessing to optimize the signal-to-noise ratio at the receiving end. Based on this link, a new virtual link is created based on methods such as power allocation, phase rotation, and linear combination to provide higher spectral efficiency using the link index. Therefore, the performance comparison result provided by this embodiment can be described in two aspects as follows: 1, since channel state information known by the transmitting end is used, the basic pre-processing concentrates the transmission energy, The signal-to-noise ratio of the receiving end on the transmission line can be greatly increased; 2, through preprocessing at the transmitting end, the new virtual link generated guarantees that the Euclidean distance between symbols is relatively large, which further improves the bit error rate performance of the system.

는 허수 단위이며, θ=π/8은 회전각을 나타낸다.Then, it is considered that the base station has four transmit antennas and the terminal has one receive antenna. The QPSK modulation scheme is still used. At this time, the spectral efficiency is 4 bps / Hz. Since the receiving end has only one antenna, the conventional equivalent post-precoding channel is a single input single output channel. Linear bond pre-treatment can not be performed. Thus, only the phase rotation extension for the pre-processing base matrix is performed. In particular, the ith (1? I? 4) column of the extended pre-processing matrix W is w _b exp {jx (i-1)?}, And the vector w _b? C ^4x1 is the pre- . The computation may be performed based on a matched filter precoding algorithm.

Is an imaginary unit, and? =? / 8 represents a rotation angle.

Figure 23 compares the bit error rate performance of a conventional solution and a pre-processing solution of the present disclosure. It can be seen that due to the reduction of the receive antenna of the terminal, the bit error rate performance of both solutions is degraded. However, the solution of the present disclosure still has excellent performance. For example, around a bit error rate of 10 ^-2 , the preprocessed multi-carrier spatial modulation system has a performance advantage of greater than 5 dB.

Example 8:

In this embodiment, the support of a solution provided by the present disclosure to a multi-user MIMO system is described. In this embodiment, the multi-user MIMO system based on preprocessing spatial modulation is as shown in FIG.

이다. 송신 데이터에 대한 전처리를 수행할 때, 기지국은 먼저 기지국으로부터 모든 단말기로의 채널 상태 정보에 따라 주파수 도메인의 프리코딩 행렬을 계산하여 각각의 단말기에 대한 프리코딩 행렬을 획득한다. 그런 다음, 기지국은 확장된 전처리 행렬을 획득하기 위해 실시예 1의 솔루션에 따라 각각의 단말기의 프리코딩 행렬을 확장하고, 각각의 단말기의 데이터에 대한 전처리를 수행한다. 전처리 후에, 기지국은 조합 모듈에서 전처리된 데이터를 조합하며, 즉 동일한 안테나 상에 송신될 데이터를 부가한다. 그런 다음, 기지국은 조합된 데이터를 안테나를 통해 송신하기 전에 조합된 데이터에 대한 IFFT 연산을 수행한다.In Fig. 24, the number of simultaneously served terminals is K. In Fig. The base station has N antennas. The i &_lt; _th > terminal has M _i antennas. The total number of receive antennas is

to be. When pre-processing for transmission data is performed, the base station first calculates a precoding matrix of the frequency domain according to channel state information from all base stations to all terminals, and acquires a precoding matrix for each terminal. Then, the base station expands the precoding matrix of each terminal according to the solution of Embodiment 1 to obtain an extended pre-processing matrix, and performs preprocessing on data of each terminal. After preprocessing, the base station combines the preprocessed data in the combining module, i. E. Adding the data to be transmitted on the same antenna. The base station then performs an IFFT operation on the combined data before transmitting the combined data via the antenna.

In particular, each of the M antennas of the K terminals is shown as a receiving end. The frequency domain channel model between the base station and the receiving end can be expressed as:

y = Hx + n,

는 제 i 단말기의 프리코딩 기본 행렬을 나타낸다. 행렬 W_i는 실시예 1의 솔루션에 따라 확장되어 제 i 단말기의 확장된 프리코딩 행렬 W_E,i∈C^NxN을 획득한다. 그 후, 각각의 단말기에 대해, 하나의 링크가 N개의 가상 링크로부터 선택되어 변조 차수 Q를 가진 심볼을 송신하고, 대응하는 확장된 프리코딩 행렬을 사용하여 송신 벡터에 대한 프리코딩이 수행되며, 심볼은 IFFT 후에 안테나를 통해 송신된다. log₂(NQ) 비트는 각각의 단말기로 송신될 수 있음을 알 수 있다.Where H? C ^MxN represents the frequency domain equivalent channel matrix. Precoding processing for this matrix is performed to eliminate interference between terminals before transmitting data. Common pre-coding solutions include matched filter precoding, zero forcing precoding, MME precoding, and block diagonal precoding. Taking the zero-forcing precoding as an example, the precoding basic matrix W _P is calculated by W _P = H ^H (HH ^H ) ^-1 = [W ₁ W ₂ ... W _K ]

Represents a precoding basic matrix of the ith terminal. Matrix W _i is performed is expanded according to the procedure of Example 1 solution to obtain a precoding matrix W _{E, i} ∈C ^NxN expansion of the i-th terminal. Then, for each terminal, one link is selected from the N virtual links to transmit a symbol with a modulation order Q, and precoding for the transmit vector is performed using the corresponding extended precoding matrix, The symbol is transmitted via the antenna after the IFFT. It can be seen that the log ₂ (NQ) bits can be transmitted to each terminal.

Through precoding, interference between terminals can be effectively reduced or even eliminated. Thus, a multi-user system may be equally viewed as a multi-user system at this time. As such, the processing at each terminal is similar to the processing of the receiving end in a single user system. That is, first, FFT processing is performed on each link to obtain a frequency domain received signal, and then the received signal is demodulated according to a channel estimation to obtain estimated transmission data. The downlink channel estimation needs to estimate the basic equivalent channel composed of the pre-processing basic matrix and the frequency domain equivalent channel of each terminal. After obtaining an estimate of the equivalent channel through channel estimation, the terminal obtains an estimate of the extended equivalent channel through the same expansion operation as the transmitter and uses the estimated value of the extended equivalent channel for demodulation of the received signal.

As compared to a conventional multi-user large scale MIMO system, if a terminal has a single antenna, the solution provided by this disclosure can have more information through the link index, so that under the same modulation scheme, Can transmit more bits. These additional bits may be used to increase system reliability through channel coding, or may be used to transmit data to increase system throughput or data rate. Or some of these bits may be coded, while other bits are used to transmit data, so that high throughput as well as high reliability can be achieved. For a terminal with multiple receive antennas, multiple antennas may provide diversity gain and increase link reliability. A terminal with multiple antennas may also be viewed as multiple single-antenna terminals to provide higher throughput and data rate.

It should be noted that the above-described multi-user architecture is applicable to the TDD mode or the frequency division duplex (FDD) mode. In particular, in the case of the TDD mode, the base station acquires channel state information of the downlink based on the uplink channel estimation through the channel correlation. In the case of the FDD mode, the base station selects the pre-processing basic matrix for each terminal according to the channel state information fed back by the terminal, and performs the extended operation.

The transmission of the reference signal in the multi-user system is similar to that in the first embodiment. The reference signals of different terminals use orthogonal resources (including time, frequency, or orthogonal codebook resources, etc.). The reference signal is processed according to the precoding basic matrix of each terminal and transmitted to the corresponding terminal. The terminal estimates its base equivalent channel and expands the base equivalent channel according to an extension method that matches the base station to obtain an estimate of the extended equivalent channel. The basic equivalent channel of each terminal is defined as an equivalent channel coefficient matrix including a precoding basic matrix, a multi-carrier modulation, an actual physical channel from the transmitting end to the terminal, and multi-carrier demodulation of the terminal. The estimated value of the extended equivalent channel of each terminal is defined as an equivalent channel coefficient matrix including an extended precoding matrix, multi-carrier modulation, an actual physical channel to the terminal at the transmitting end, and multi-carrier demodulation of the terminal.

Example 9:

Embodiments 6, 7 and 8 provide a comparison of the application and performance of the solution provided by this disclosure under TDD mode. A common feature of this embodiment is that the base station knows the correct channel state information, which greatly facilitates the calculation of the precoding basic matrix at the transmitting end. However, in FDD mode, this is difficult to implement. This embodiment provides an implementation under FDD mode.

In FDD mode, it is difficult for the base station to obtain accurate channel state information, which leads to a great deal of difficulty in calculating the pre-processing base matrix. However, based on the principle of the solution provided by this disclosure, the pre-processing base matrix may be independent of channel state information. Although the calculation of the pre-processing base matrix based on known channel state information may increase the received signal-to-noise ratio of the terminal, a randomly selected pre-processing base matrix may also be used to generate the base channel link, Lt; / RTI > Thus, the solution of this disclosure is also applicable to the FDD mode. Hereinafter, the implementation of the present disclosure in the FDD mode will be described with reference to an embodiment.

25 is a flow diagram illustrating a signal processing procedure based on a fixed pre-processing base matrix in FDD mode in accordance with an embodiment of the present disclosure. In this embodiment, the calculation does not depend on the feedback from the terminal to the base station, since it is not necessary to calculate the pre-processing base matrix according to the channel state information. In this embodiment, a signal processing procedure based on a fixed pre-processing base matrix includes: first, the base station selects an appropriate code word from a fixed codebook set as a pre-processing base matrix. The matrix may be randomly selected or it may be a suitable codeword selected according to channel state information fed back by the terminal. In a second situation, during downlink channel estimation, the base station may perform pre-processing on the reference signal transmitted based on the predefined codebook. The terminal selects a codeword having a maximum received signal-to-noise ratio and feeds back the index of the codeword. The base station takes the codeword fed back by the terminal as a pre-processing base matrix. Then, after the pre-processing basic matrix is selected, a corresponding pre-processing matrix expansion operation can be performed. Similar to Embodiment 1, linear combination, phase rotation and / or power allocation for the columns of the pre-processing base matrix can be performed to obtain an extended pre-processing matrix. Finally, pre-processing is performed on the spatial modulation symbols transmitted in the extended pre-processing matrix, and the preprocessed symbols are transmitted through the respective antennas after the IFFT operation.

For channel estimation, the base station selects a pre-processing base matrix and then transmits a demodulation reference signal used to estimate a base equivalent channel and performs a preprocessing on the reference signal with a pre-processing base matrix. After obtaining an estimate of the base equivalent channel based on the demodulation reference signal, the terminal may then calculate the estimate of the base equivalent channel (including linear combination of columns, phase rotation and power allocation) And performs an expansion operation that coincides with that of FIG. Finally, the terminal performs spatial demodulation processing on the received signal according to an estimate of the extended equivalent channel to obtain an estimate of the transmitted bitstream.

Hereinafter, the efficiency of the solution provided by this embodiment will be described with reference to a performance simulation.

First, it is assumed that the base station has four transmit antennas and the terminal has one receive antenna. A QPSK modulation scheme is used. At this time, the spectral efficiency is 4 bps / Hz. Three of these solutions are considered:

The first solution adopts a fixed pre-processing base matrix as described in this embodiment, and the pre-processing base vector is fixedly selected as w _b = [1 j 1 -j] ^T at the base station, where j is an imaginary unit.

The second solution adopts a fixed pre-processing basic matrix as described in this embodiment, and the base station selects a code word from a pre-set codebook as a pre-processing basic matrix according to channel state information fed back by the terminal. The codebook used in the simulation in this embodiment is described by the following matrix:

Here, each column of the matrix represents a codeword, and the codeword is orthogonal. j represents an imaginary unit. The preprocessing of the two solutions described above includes phase rotation and power allocation. The phase rotation angle is a multiple of π / 8 and the power allocation ratios are P1: P2: P3: P4 = 5: 6: 7: 8 where P _i is the transmission power of the i th link, Normalized.

The third solution is a conventional multi-carrier spatial modulation system.

Figure 26 shows a comparison of the bit error rate performance of the three solutions described above. It can be seen that when the base station does not consider the channel state information, i.e. the first solution in which the same pre-processing base matrix is selected for different subcarriers, the performance is inferior or similar compared to conventional multi-carrier spatial modulation. The advantages of such a solution are as follows: Only the equivalent channel needs to be estimated before expansion, thus reducing the overhead for downlink equivalent channel estimation. A second solution that takes channel state information into account has obvious advantages. For example, when the bit error rate is about 10 ^-2 , the third solution has an additional 5 dB gain over the existing solution. However, the second solution must perform physical channel estimation based on the codebook that results in some overhead.

Now, another situation is considered in which the base station has 16 antennas and the terminal has one antenna. The QPSK modulation scheme is still in use. At this time, the spectrum efficiency is 6 bps / Hz. The following two solutions are considered: The first solution adopts a fixed pre-processing basic matrix as described in the present embodiment, and the base station generates a pre-processing basic matrix as a pre-processing basic matrix according to the channel state information fed back by the terminal. Lt; / RTI > The codebook employed in the simulation includes four columns selected at equal intervals from a DFT matrix with dimension 16,

Each column in the above matrix represents a codeword. The second solution is a conventional multi-carrier spatial modulation system.

Figure 27 shows a comparison of the bit error rate performance of the two solutions described above. Compared to the conventional solution, it can be seen that the solution provided by this disclosure can achieve better performance even if a small codebook is employed. In addition, the use of small codebooks can reduce the overhead of downlink channel estimation. The foregoing shows that even in FDD mode, the solution provided by this disclosure can achieve an apparent performance gain with relatively small channel estimation and feedback costs. When the receiving end has multiple antennas, the codebook can be designed to take a row full rank matrix as a codeword. The transmitting end selects a codeword matrix as a pre-processing basic matrix according to the feedback from the receiving end, and acquires an extended pre-processing matrix. In such a scenario, the flexibility of the extended operation can be improved by taking the row full rank matrix as a preprocessing base matrix, which is advantageous for obtaining better bit error performance by having a large symbol distance.

Tenth Embodiment:

This embodiment provides an adaptive parameter adjustment scheme of the method provided by this disclosure.

For a time-variant channel environment in an actual communication scenario, the system parameters need to be adjusted in real time in accordance with channel state information to optimize system performance. With respect to the solution provided by this disclosure, the following are provided: channel state information: dimension of the extended pre-processing matrix, dimension and selection mode of the pre-processing base matrix, selection of phase rotation angle, selection of power allocation, The insertion frequency of the pilot used to estimate the equivalent channel, and the like. 28 is a schematic diagram illustrating generation of a preprocessing matrix based on adaptive parameter selection in accordance with an embodiment of the present disclosure;

If the channel changes rapidly, the channel estimation error may lead to an inaccuracy of the estimation of the effective channel. In a solution provided by this disclosure, a virtual link is created using phase rotation and power allocation. Thus, channel estimation errors may lead to Euclidean distances between symbols leading to an increase in bit error rate. The dimension of the extended preprocessing matrix W may be an integer N _c ≥ N _b where N _c represents the number of columns of the matrix W and N _b represents the number of columns of the preprocessing base matrix And the dimension of the extended preprocessing matrix W determines the number of valid transmission links to determine the number of bits transmitted in the spatial domain so that the higher dimension can increase the data rate, And increase the Euclidean distance between the symbols at the receiving end to increase the estimation accuracy of the system. Adjustment of the dimension of the extended pre-processing matrix W also leads to adjustment of phase rotation and power allocation. In particular, if the channel changes rapidly and the channel estimate at the receiving end is incorrect, then the estimation accuracy at the receiving end needs to be increased. Thus, an extended preprocessing matrix with a power allocation mode with a large difference between the low dimension, the large phase rotation angle and the power allocation factor can be selected. Conversely, if the channel condition is good, it may be an object to increase the system data rate. Thus, an extended matrix with a power allocation mode with a slight difference between high dimension, small phase rotation angle and power allocation factor can be selected.

In the FDD mode, the pre-processing base matrix is selected based on the channel state information. Therefore, the number of columns is not determined by the number of transmitting antennas or the number of receiving antennas. The preprocessing base matrix with more columns can provide more flexibility for subsequent expansion operations and is advantageous for improving system performance. However, the overhead used for downlink equivalent channel estimation is increased at the same time. Thus, when the channel changes rapidly or selects a higher frequency / time, a pre-processing base matrix with more columns may be used to increase link reliability; Otherwise, a pre-processing base matrix with fewer rows may be selected to reduce the overhead of downlink equivalent channel estimation.

. 이러한 행렬 중에서, 전처리 기본 행렬의 행의 수 N만이 송신 안테나의 수와 일치해야 한다. N_b 및 N_c는 수신 단으로부터의 피드백에 따라 결정될 수 있다. 예를 들어, N_b는 등가 채널의 채널 가변 속도 또는 랭크와 같은 채널 상태 정보에 의해 결정될 수 있거나 이용 가능한 기준 신호에 의해 결정될 수 있다. N_c는 수신 단에 의해 피드백되는 채널 상태 정보와 수신 단에 의해 필요로 되는 데이터 속도에 의해 결정될 수 있다.The above selection of the dimension of the preprocessing matrix shows that W = W _b and _e , where

. Of these matrices, only the number N of rows of the pre-processing basic matrix must match the number of transmitting antennas. N _b and N _c may be determined according to the feedback from the receiving end. For example, N _b may be determined by channel state information, such as the channel variable rate or rank of the equivalent channel, or may be determined by an available reference signal. N _c can be determined by the channel state information fed back by the receiving end and the data rate required by the receiving end.

In addition, there may be a large error when estimating only the basic equivalent channel and restoring the extended equivalent channel based on the basic equivalent channel when the channel is changing rapidly or choosing a high frequency / time, do. At this time, it is possible to estimate the channel of some virtual link to correct the estimated value of the extended equivalent channel. In this embodiment, the reference signal insertion and channel estimation procedure is as shown in FIG.

In Fig. 29, the reference signal is inserted twice. First, after the pre-processing base matrix is generated, preprocessing for reference signal 1 is performed using the pre-processing base matrix. The terminal estimates an equivalent channel according to the reference signal 1. The terminal then expands the equivalent channel using an extension rule that matches the base station to obtain an estimate of the extended equivalent channel. After acquiring the extended pre-processing matrix, the base station inserts the second reference signal 2, preprocesses the reference signal 2 using the extended pre-processing matrix, and transmits the pre-processed reference signal 2. The terminal estimates the extended virtual link channel according to the reference signal 2 and corrects the previously obtained estimate of the extended equivalent channel based on the extended virtual link channel. It should be noted that since the second inserted reference signal is only used to correct the estimate of the equivalent channel, the insertion density can be adjusted according to the reliability of the channel. For example, if the current channel condition is good and the data transmission is relatively reliable, the insertion density of the reference signal at the second may be low or insertion may not be necessary. If the channel conditions are not good and the data transmission is less reliable, then the insertion density of the reference signal at the second needs to be increased.

Example 11:

This embodiment provides an implementation of an open loop system for a single antenna terminal provided by the solution of this disclosure. It is assumed that the base station already knows channel state information and that the terminal has a single antenna. At this time, the base station needs to increase the Euclidean distance between symbols at the receiving end by selecting the pre-processing basic matrix, power allocation, and phase rotation operation. The criterion for selecting the power allocation factor and phase rotation angle is that the minimum distance between the constellation points in the equivalent constellation at the single antenna receiving end is made as large as possible through power allocation and phase rotation between the different links.

First, the following situation is considered: the base station has four antennas and a QPSK modulation scheme is adopted. At this time, the spectral efficiency is 4 bps / Hz. A matrix having four rows and one column is selected as the pre-processing basic matrix. The extended preprocessing matrix is generated through power allocation and phase rotation operations. The choice of power allocation factor and phase rotation angle is shown in Table 4. It should be noted that the generation of the phase rotation angle takes into account the amplitude and phase relationship between the QPSK constellation and the 16QAM constellation.

[Table 4]

Table 4: Selection of power allocation factor and phase rotation angle when the transmitting end has four antennas

Based on the power allocation factors and phase rotation angles as shown in Table 4, satisfactory Euclidian distances between symbols can be obtained in the constellation at the receiving end. Figure 30 shows constellations with preprocessing obtained by the receiving end for specific channel realization and constellations without preprocessing. The left side of Figure 30 shows the original constellation at the receiving end obtained without pre-processing. It can be seen that due to the effect of channel time and frequency selective fading, the Euclidean distance between some constellation points of the equivalent constellation at the receiving end is rather small, which degrades the system estimation performance. The right part of FIG. 30 shows the constellation at the receiving end when preprocessing is performed. The equivalent constellation at the receiving end is similar to the rotated 16QAM constellation. The average minimum Euclidean distance is increased. Therefore, the system estimation performance is improved. Figure 31 shows a comparison of the bit error rate performance of the two solutions described above. It can be seen that due to the increase in the distance between the symbols, the solution including the pre-processing has improved bit error rate performance.

Then, another situation is considered: the base station has 16 antennas, and the QPSK modulation scheme is still used. At this time, the spectrum efficiency is 6 bps / Hz. A vector with 16 rows and 1 column is randomly selected as the pre-processing base matrix. The selection of the power allocation factor and the phase rotation angle is as shown in Table 5.

[Table 5]

Table 5: Selection of power allocation factor and phase rotation angle when the base station has 16 antennas

32 is a schematic diagram illustrating equivalent constellation with preprocessing at the receiving end and equal constellation without preprocessing for specific channel realization; As shown by the left constellation of FIG. 32, in the absence of preprocessing, due to the influence of the channel, the Euclidian distance between some points in the equivalent constellation at the receiving end is somewhat smaller, thereby degrading the system bit error rate performance . However, as shown in the right part of Figure 32, after pre-processing, the equivalent constellation at the receiving end is similar to the rotated constellation of 16QAM, where there is no Euclidian distance between each pair of constellation points Is guaranteed. Thus, the minimum Euclidean distance between symbols is greatly increased, and the bit error performance of the entire system is improved.

33 is a schematic diagram illustrating a comparison of the bit error rate performance of the two solutions described above when the base station has 16 antennas. As the data rate increases, the number of constellation points in the equivalent constellation at the receiving end also increases. Thus, the system is susceptible to interference by noise. After preprocessing, the minimum Euclidean distance between the constellation points is increased. Thus, the system has improved capability for noise and the bit error rate performance of the overall system is improved. From FIG. 33, it can be seen that the bit error rate performance of the system is improved after the pre-processing method provided by this disclosure is applied.

It should be noted that, in this embodiment, a constellation similar to the QAM modulation scheme is generated at the receiving end through power allocation and phase rotation. Other types of constellations may also be generated by adjusting power allocation and phase rotation values. However, the basic criterion is to make the minimum Euclidean distance between the constellation points of the equivalent constellation at the receiving end as large as possible.

Example 12:

This embodiment applies the solution of this disclosure to reduce the reference signal overhead. It is assumed that the base station has four transmit antennas, the receiving end has one receive antenna, and the base station does not know the channel state information. The pre-processing base matrix is defined as:

The rank of the preprocessing basic matrix is 3, that is, the column vectors of the matrix are not linearly correlated. The matrix is extended through a linear combination of the columns of the matrix, i.e., the first three columns of the extended pre-processing matrix are the three columns of the preprocessing matrix W _b , and the fourth column is w ₄ = w ₁ -w ₂ + w ₃ . Thus, the extended preprocessing matrix is obtained as follows:

The extended equivalence matrix is:

There are still four simultaneous links. To transmit a spatial modulation symbol as described in the above embodiment, one of the four equivalent links is activated during each transmission. The information is transmitted via the active link and the index of the transmitted symbol.

Since the column rank of the preprocessing basic matrix is 3, only three reference signals using orthogonal resources are required to complete the estimation of the basic equivalent channel. Then, through the extension of the extended matrix W _e , an extended equivalent channel can be obtained and an estimate of the transmitted signal can be implemented.

The embodiments described above show that a pre-processing base matrix with a corresponding thermal rank can be designed according to the amount of available reference signal or the amount of resources available to transmit the reference signal. The expanded preprocessing matrix may be generated through a simple linear combination of the columns of the preprocessing matrix. It is possible to achieve a high data rate with the overhead of a relatively low reference signal. As such, a tradeoff between the overhead of the reference signal and the data rate can be obtained. Considering that the length of the reference signal is generally a power of two, the occupied orthogonal resource is also a power of two. If the required reference signal does not meet this condition, the unused reference signal resource may be used to transmit data to reduce overhead.

The above-described embodiment is taken as an example. Assume that the length of the reference signal is 4. The number of required reference signals is three, but four orthogonal resources are still needed to transmit the reference signal. Therefore, the overhead of the reference signal does not change. At this time, the orthogonal resources not used for transmitting the reference signal can be used to transmit data, and the data can be differentiated from the reference signal by the orthogonal cover code technique, thereby reducing the overhead of the reference signal.

According to the signal transmission method described above based on multi-carrier spatial modulation, the embodiment of the present disclosure provides a transmitting apparatus as shown in Fig. The transmitting apparatus includes a first pre-processing basic matrix calculating module, a first pre-processing matrix extending module, a first reference signal transmitting module, and a first data transmitting module; here,

The first pre-processing basic matrix calculation module is set to determine a pre-processing basic matrix;

The first pre-processing matrix expansion module is set to extend the pre-processing basic matrix to obtain an extended pre-processing matrix;

The first reference signal transmission module is configured to perform preprocessing on the first reference signal with the pre-processing basic matrix and to transmit the preprocessed first reference signal to the receiving device;

The first data transmission module performs symbol mapping and spatial modulation on the bit stream to be transmitted, performs spatial modulation on the extended pre-processing matrix, preprocesses the obtained symbols, and performs multicarrier modulation on the preprocessed symbol And is configured to transmit the symbol to the receiving apparatus.

According to the above-described signal transmission method of a multi-user system based on multi-carrier spatial modulation, the embodiment of the present disclosure provides a transmitting apparatus as shown in Fig. The transmitting apparatus includes a second pre-processing basic matrix calculating module, a second pre-processing matrix extending module, a second reference signal transmitting module, and a second data transmitting module; here,

The second pre-processing basic matrix calculation module is set to select a pre-processing basic matrix for each terminal according to channel state information;

The second pre-processing matrix expansion module is set to extend the pre-processing basic matrix of each terminal to obtain a corresponding extended pre-processing matrix;

The second reference signal transmitting module is configured to perform preprocessing on the reference signal with the pre-processing basic matrix and transmit the preprocessed reference signal to the corresponding terminal; A reference signal transmitted to a different terminal uses orthogonal resources;

The second data transmission module performs symbol mapping and spatial modulation on the bit stream of each terminal, preprocesses the spatial modulation symbols using the corresponding extended pre-processing matrix, and preprocesses symbols of the respective terminals , Performs multi-carrier modulation on the combined symbols, and is configured to transmit symbols.

According to the above-described signal transmission method based on multi-carrier spatial modulation, the embodiment of the present disclosure provides a receiving apparatus as shown in Fig. The receiving device includes a receiving module, a basic equivalent channel estimation module, an extended equivalent channel estimation module and a demodulation module; here,

The receiving module is set to receive a first reference signal and data;

The basic equivalent channel estimation module is set to estimate a basic equivalent channel based on a first reference signal;

The extended equivalent channel estimation module is set to extend the basic equivalent channel using a scheme consistent with the scheme used by the transmitting apparatus to extend the pre-processing base matrix to obtain an estimate of the extended equivalent channel;

The demodulation module is configured to demodulate the data according to an estimate of the extended equivalent channel to obtain the original data.

In one embodiment, the receiving module of the receiving device further receives a second reference signal;

The extended equivalent channel estimation module further corrects the estimate of the extended equivalent channel according to the second reference signal.

Example 13:

In this embodiment, a combination method of preamble based on antenna port grouping and spatial modulation will be described.

It is assumed that a plurality of UEs are serviced in one cell. In order to service a plurality of UEs in a broadcast manner, the methods of Embodiments 1 to 5 may be applied. A preprocessing method can be applied to improve performance. In particular, antenna grouping is based on the effective antenna port generated by the preprocessing. The basic procedure is described as follows.

1. UE estimates downlink channel state information via CSI-RS or CRS and reports the corresponding channel state information to BS by using quantized CSI or codebook based CSI feedback. At this stage, the base station can obtain downlink CSI from multiple UEs. Another way to obtain the downlink CSI is to make an estimate over the uplink channel using the channel correlation of the TDD mode.

2. According to the downlink CSI from multiple UEs, UEs with similar downlink channel status information are grouped as one group. For one UE group, one downlink CSI is used to compute the preprocessing matrix. One possible way to obtain the downlink CSI for one UE group is to average all downlink CSIs for the UEs of this UE group.

3. Based on the downlink CSI for the UE group, the pre-processing matrix is calculated based on the method proposed in Examples 1-5. In particular, a two-step method is used that includes extensions using basic pre-processing matrix calculations based on downlink CSI for UE groups and predefined extension methods. In this step, an effective antenna port corresponding to the valid link is formed.

4. Based on the effective antenna port, antenna port grouping may be performed. Considering that the preprocessing procedure may be transparent to the UE, the only thing that needs to be notified to the UE is the antenna port grouping information, and the notification method proposed in the previous embodiment can be applied.

5. Broadcast information is transmitted to multiple UEs in a group based on layered spatial modulation.

Note that the above-mentioned layering of the transmitted data in the previous embodiment can still be applied to the preprocessing based approach. In addition, the channel time selectivity as well as the channel frequency selectivity will determine the parameters of the preprocessing method as demonstrated in the previous embodiments.

If there is no UE grouping procedure or there is no downlink CSI of multiple UEs, a random base matrix or a fixed base matrix may be used to generate the pre-processing matrix. In this way, feedback with little performance loss is not required.

The foregoing is merely a preferred embodiment of the present application and is not intended to limit the present application, and any modifications, equivalents, and improvements made within the spirit and principle of the present application should fall within the scope claimed by the present application.

Claims (15)

In the signal transmission method,
Transmitting link grouping setting information by a transmitter, the link grouping setting information being information of the link included in each group after dividing the link into at least two groups;
Layering a data flow to be transmitted according to the grouping of the links by the transmitter;
Performing spatial modulation on the layered data flow by the transmitter;
Performing, by the transmitter, multicarrier modulation on a spatially modulated signal; And
And transmitting, by the transmitter, the multi-carrier modulated signal. The method according to claim 1,
Wherein dividing the link into at least two groups comprises:
Dividing all available links into at least two groups, the group being a group of a first hierarchy;
Further dividing each of the groups of the first hierarchy into at least two groups each, wherein the generated group is a group of a second hierarchy; And
By this analogy, performing the segmentation until each group contains only one link or the setting requirements of the link grouping are satisfied;
The step of layering, by the transmitter, a data flow to be transmitted according to the grouping of the links,
Transmitting the basic data using the group of the first layer and transmitting the auxiliary data using each group of the first layer and the other layer based on the previous layer, The method comprising: transmitting at least one of extended data based on basic data, redundant information of data of a previous layer, and a combination of the extended data and the redundant information; And
Using the constellation point symbol of the spatial modulation to transmit data in the lowest layer or to transmit other supplemental or redundant information;
The criterion for dividing the link into groups is to assign the links having a correlation index greater than a setting threshold to a group;
The method further comprises: estimating, by the transmitter, a correlation index between links according to information from the receiver, thereby dynamically adjusting the number of links and the grouping of links; Wherein the information from the receiver comprises channel state information fed back from the receiver and / or a sounding reference signal sent to the transmitter via an uplink channel by the receiver;
The method further comprises assigning users having the same link grouping configuration information to one group and performing a broadcast service on the same time-frequency resource for users in the same group , And a signal transmission method. 3. The method according to claim 1 or 2,
Further comprising: pre-processing the space-modulated signal and then performing the multi-carrier modulation and transmission;
The preprocessing step comprises performing power adjustment on the link and / or phase adjustment on the link;
Wherein performing power adjustments on the link comprises adjusting the average transmit power of each of the groups in the first layer such that each of the groups has a different average transmit power while maintaining transmit power unchanged; Each of the groups in the second layer such that each of the groups of the second layer can have different average transmission power while maintaining the average transmission power of each of the groups in the first layer unchanged. Adjusting average transmission power; And performing, by this analogy, an adjustment until adjustment of the average transmit power of each of the groups of the lowest layer is completed;
The criterion for adjusting the average transmission power of the group in each layer is that the power adjustment amount of the layer is not greater than the power adjustment amount of the previous layer;
Wherein performing phase adjustment on the link comprises randomly selecting a rotation phase for each link of the group of the lowest layer, wherein the interval of each rotation phase of the link belonging to a different group does not intersect Selecting the adjacent rotational phase intervals for each link of the group belonging to the same group in the previous layer;
The method further comprises transmitting, by the transmitter, a reference signal according to the grouping of the links;
The step of transmitting, by the transmitter, the reference signals in accordance with the grouping of the links comprises the steps of: transmitting, by the transmitter, the same time-frequency resources for the links belonging to the same group Using the same reference signal sequence;
The method may further comprise performing the pre-processing on the reference signal prior to transmitting the reference signal if the multicarrier modulation and transmission is performed after pre-processing the spatially modulated signal;
The method further includes partitioning the layered data in each of the layers into blocks and adding a cyclic redundancy check (CRC) code independent of the data in each layer of each block of data ;
The transmitter transmitting link number information and link grouping configuration information in at least one of a physical broadcast channel, a physical downlink control channel, and a physical downlink shared channel;
Wherein the transmitter transmits on the physical broadcast channel, a physical downlink control channel or a physical downlink shared channel with an additional field added, the additional field indicating the link number information and the link grouping setting information;
Wherein the transmitter transmits link number information using a CRC check mask of the physical broadcast channel, each of the transmission modes of the physical broadcast channel corresponds to at least two CRC checkmasks, and each CRC checkmask Correspond to one kind of information about the number of links; The transmission mode of the physical broadcast channel includes a single antenna port transmission mode, a dual antenna port transmission diversity mode, and a four antenna port transmission diversity mode;
Characterized in that the transmitter transmits on the physical broadcast channel, a physical downlink control channel or a physical downlink shared channel with an additional field, and the additional field represents the link grouping setup information. Way. In the transmitter,
A setting module for transmitting link grouping setting information, wherein the link grouping setting information is information of the link included in each group after dividing the link into at least two groups;
A data layering module for layering a data flow to be transmitted according to the grouping of the links;
A spatial modulation module for performing spatial modulation on the layered data flow;
A multi-carrier modulation module for performing multi-carrier modulation on a space-modulated signal; And
And a transmitter module for transmitting the multi-carrier modulated signal. In the signal receiving method,
Receiving, by the receiver, link grouping setting information;
Acquiring, by the receiver, grouping of links included in each of the groups according to the link grouping setting information and information of the links;
Performing, by the receiver, layered detection of the received data according to the grouping of the links;
The step of performing, by the receiver, layered detection of the received data according to the grouping of the links,
Detecting, by the receiver, data transmitted from all layers according to channel status information of each link, and determining the number of layers to be maintained according to a setting criterion; Wherein the setting criteria comprises: comparing a previously set signal-to-noise ratio threshold and an estimated signal-to-noise ratio of detected data from each layer; and if the signal-to-noise ratio threshold is greater than the threshold, And performing subsequent processing, but not performing subsequent processing; Or the setting criterion comprises determining, by the transmitter, whether to maintain the data of the corresponding layer for each receiver according to whether a CRC check added by the transmitter independently for each layer of data has been passed ;
The method comprises the steps of: detecting data of each layer by layer according to channel state information of each group; and comparing the estimated signal-to-noise ratio of detected data from each of the layers with a preset signal-to-noise ratio threshold Further comprising performing subsequent detection of data in a next layer if the signal to noise ratio threshold is greater than the signal to noise ratio threshold and otherwise terminating the detection;
Wherein the method further comprises: receiving, by the receiver, a reference signal according to the grouping of the links, and performing channel estimation. In the receiver,
A setting information receiving module for receiving the link grouping setting information;
A grouping acknowledgment module for grouping links included in each of the groups according to the link grouping setting information and acquiring information about the links; And
And a detection module for performing layered detection on the received data according to the grouping of the links. A signal transmission method based on multi-carrier spatial modulation,
Expanding the pre-processing base matrix to determine a pre-processing base matrix and obtaining an extended pre-processing matrix;
The transmitting apparatus preprocesses the first reference signal with the pre-processing basic matrix and transmits the pre-processed first reference signal to the receiving apparatus;
The transmitting apparatus performs symbol mapping and spatial modulation on a bit stream to be transmitted, preprocesses symbols obtained after spatial modulation with an extended pre-processing matrix, and transmits a preprocessed symbol to the receiving apparatus after multicarrier modulation ;
The step of determining the pre-processing basic matrix may include calculating the pre-processing basic matrix according to channel state information, using a pre-defined pre-processing basic matrix, or using a pre- Selecting a pre-processing basic matrix;
Wherein the step of calculating the pre-processing basic matrix according to the channel state information includes calculating the pre-processing basic matrix according to a channel coefficient matrix using a precoding algorithm; Wherein the precoding algorithm comprises at least one of a matched filter algorithm, a zero-forcing algorithm, and a least mean squared error precoding algorithm;
Wherein the channel coefficient matrix comprises multi-carrier modulation, an actual physical channel between the transmitting apparatus and the receiving apparatus, and an equivalent frequency-domain channel coefficient configured by the multi-carrier demodulation. 8. The method of claim 7,
Further comprising the step of the transmitting apparatus determining the number of columns of the extended preprocessing matrix according to the information fed back by the receiving apparatus;
Wherein expanding the preprocessing base matrix to obtain the expanded preprocessing matrix comprises:
Performing a linear combination on a column of the preprocessing basic matrix to obtain a column of the extended preprocessing matrix;
Performing a phase rotation on a column of the preprocessing matrix to obtain a column of the extended preprocessing matrix, wherein the rotated phases of the different elements of each column are the same or different;
Multiplying a power allocation factor by a column of the pre-processing basic matrix to obtain a column of the extended pre-processing matrix;
Wherein the number of columns of the pre-processing basic matrix is equal to the number of transmission antennas, and the number of columns of the pre-processing basic matrix is the number of available reference signals or the reference signal fed back by the receiving apparatus Determined by the transmitting apparatus according to the amount of available resources;
Wherein the number of rows of the extended pre-processing matrix is equal to the number of rows of the pre-processing basic matrix, and the number of columns of the extended pre-processing matrix is greater than or equal to the number of columns of the pre-processing basic matrix. 9. The method according to claim 7 or 8,
Processing the second reference signal with the extended pre-processing matrix and transmitting the pre-processed second reference signal to the receiving apparatus;
Further comprising adjusting the insertion density of the second reference signal according to the channel state information fed back by the receiving apparatus,
Selecting at least one of the columns of the preprocessing matrix to be inserted at a density lower than the number of columns of the preprocessing matrix or selecting to insert at a density equal to the number of columns of the preprocessing matrix, ;
Wherein the first reference signal is used to estimate a basic equivalent channel and the second reference signal is used to correct an estimate of the extended equivalent channel;
Wherein the basic equivalent channel is comprised of the pre-processing basic matrix, multi-carrier modulation, real physical channel and multi-carrier demodulation. In the transmitting apparatus,
A first pre-processing matrix multiplication module, a first pre-processing matrix multiplication module, a first reference signal transmission module, and a first data transmission module,
Wherein the first pre-processing basic matrix calculation module is set to determine a pre-processing basic matrix;
Wherein the first pre-processing matrix expansion module is set to extend a pre-processing base matrix to obtain an extended pre-processing matrix;
Wherein the first reference signal transmission module is configured to perform preprocessing on the first reference signal with the pre-processing basic matrix and to transmit the pre-processed first reference signal to the receiving device;
The first data transmission module performs symbol mapping and spatial modulation on a bitstream to be transmitted, performs preprocessing on symbols obtained after spatial modulation with an extended pre-processing matrix, modulates the pre- And is set to transmit to the receiving apparatus. A signal transmission method based on multi-carrier spatial modulation in a multi-user system,
The transmitting apparatus selecting a pre-processing basic matrix for each terminal according to channel state information and extending the pre-processing basic matrix of each terminal to obtain a corresponding extended pre-processing matrix;
Processing the reference signal with a respective pre-processing matrix and transmitting the pre-processed reference signal to a corresponding terminal, wherein the reference signal transmitted to a different terminal uses orthogonal resources, ;
Performing a symbol mapping and a spatial modulation on each bit stream of each terminal and performing pre-processing on symbols obtained after the spatial modulation of each terminal with the corresponding extended pre-processing matrix; And
Wherein the transmitting device combines the preprocessed symbols of each terminal to transmit the combined symbols after multi-carrier modulation. 12. The method of claim 11,
The terminals being simultaneously receiving and using the same time-frequency resources;
Wherein the step of the transmitting device selecting the pre-processing basic matrix for each terminal according to the channel state information comprises the steps of the transmitting device calculating the pre-processing basic matrix according to a channel coefficient matrix, And selecting the pre-processing basic matrix from a pre-defined codebook according to the channel state information;
Wherein the channel coefficient matrix comprises a multi-carrier modulation, an actual physical channel between the transmitting apparatus and all terminals, and an equivalent frequency domain channel coefficient consisting of multi-carrier demodulation of each terminal;
The combining comprising adding the symbol to be transmitted on the same link. A transmission apparatus applicable to a multi-user system based on multi-carrier spatial modulation,
A second pre-processing matrix multiplication module, a second pre-processing matrix multiplication module, a second reference signal transmission module, and a second data transmission module;
Wherein the second pre-processing basic matrix calculation module is configured to select a pre-processing basic matrix for each terminal according to channel state information;
The second pre-processing matrix expansion module is set to extend the pre-processing basic matrix of each terminal to obtain a corresponding extended pre-processing matrix;
Wherein the second reference signal transmission module is configured to perform preprocessing of the reference signal with each pre-processing basic matrix and transmit the pre-processed reference signal to the corresponding terminal, and the reference signal transmitted to the different terminal uses the orthogonal resource ;
Wherein the second data transmission module performs symbol mapping and spatial modulation on bit streams of each terminal and preprocesses symbols obtained after the spatial modulation on the corresponding extended pre-processing matrix, And preprocessed symbols are combined to transmit the combined symbols after multicarrier modulation. A signal reception method based on multi-carrier spatial modulation,
Receiving a first reference signal and estimating a basic equivalent channel based on the first reference signal;
Extending the estimate of the basic equivalent channel using a scheme consistent with the scheme used by the transmitting apparatus to extend the pre-processing base matrix so that the receiving apparatus obtains an estimate of the extended equivalent channel;
Demodulating the received data according to an estimate of the extended equivalent channel to receive the data and to acquire original data; And
The receiving device receiving a second reference signal and correcting the estimate of the extended equivalent channel in accordance with the second reference signal. In the receiving apparatus,
A receiving module, a basic equivalent channel estimation module, an extended equivalent channel estimation module and a demodulation module;
The receiving module being configured to receive a first reference signal and data;
Wherein the basic equivalent channel estimation module is configured to estimate a basic equivalent channel based on the first reference signal;
Wherein the extended equivalent channel estimation module is configured to extend the basic equivalent channel using a manner consistent with that used by the transmitting device to extend the pre-processing basic matrix to obtain an estimate of the extended equivalent channel;
The demodulation module being configured to demodulate the data according to an estimate of the extended equivalent channel to obtain original data;
The receiving module is further configured to receive a second reference signal;
Wherein the extended equivalent channel estimation module is further configured to correct an estimate of the extended equivalent channel in accordance with the second reference signal.

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