CN107425893A - Generalized spatial modulation system sending and receiving end antenna selecting method based on power system capacity - Google Patents

Abstract

The invention belongs to the technical field of communication, and relates to a method for selecting an antenna at a transceiver end of a generalized space modulation system based on system capacity. The present invention provides a method for selecting transceiver antennas of a generalized space modulation system based on system capacity. The technology selects a suitable transceiver antenna set according to channel information, so that the capacity of the system is significantly improved, and the system introduces less The BER performance of the system is improved with a small amount of feedback and a small increase in complexity.

Description

An Antenna Selection Method for Transmitter and Receiver of Generalized Spatial Modulation System Based on System Capacity

technical field

The present invention belongs to the technical field of communication anti-jamming, and relates to generalized spatial modulation (Generalized Spatial Modulation, SM) technology, quadrature amplitude (Quadrature Amplitude Modulation, QAM) modulation technology, and related MIMO (Multiple Input Multiple Output) technology, more specifically It is said to be a method for selecting antennas at the transceiver end of a generalized spatial modulation system based on system capacity.

Background technique

MIMO modulation technology is a high-speed transmission technology in a wireless environment. It configures more antenna units at the transmitting end and/or receiving end, and combines advanced space-time coding modulation schemes. By making full use of the degree of freedom of space, it can Brings additional diversity, multiplexing and beamforming gains.

Recently, spatial modulation technique as a new MIMO modulation scheme has been proposed as a new modulation technique. The basic principle of this technology is to transmit information bits by activating different antennas and using the antenna index value for modulation. The essence of this transmission scheme is to exploit the independence of different channels in a MIMO system. Because only one antenna is activated at a time, only one radio frequency unit is required at the transmitting end and this process can transmit part of the bits, so this scheme increases the transmission rate and reduces the cost and complexity of the MIMO system. The generalized spatial modulation system is extended on the basis of the spatial modulation system, and multiple transmit antennas are activated in each time slot, which improves the spectrum utilization efficiency of the system. However, there is a certain loss in its BER performance.

Contents of the invention

The purpose of the present invention is to solve the problems existing in the above-mentioned prior art, and to provide a method for selecting antennas at the transceiver end of a generalized spatial modulation system based on system capacity, and obtain a significant increase in BER performance at the cost of adding less complexity. improve.

The technical solution of the present invention is: based on the generalized spatial modulation system antenna selection method of the system capacity, it is defined that each receiving antenna combination in the generalized spatial modulation system includes N _rs root receiving antennas, and each transmitting antenna combination includes N _ts transmitting antennas, each transmitting antenna combination set contains m transmitting antenna combinations, and m is the power of 2, the purpose of this method is to select the receiving antenna combination {R ₁ ...R _n } and the transmitting antenna combination set {C The combination [R _i , C _Rj ] of _R1 ... C _Rm } is characterized in that it comprises the following steps:

a. Obtain the capacity lower bound β _ij of the GSM system composed of each receiving antenna combination R _i and a group of transmitting antenna combination sets C _Rj :

Among them, H _k represents the channel matrix formed by the kth transmit antenna combination under the antenna combination, Represents a unit square matrix of size N _ts , ρ represents the signal-to-noise ratio;

b. Select the receiving antenna combination and transmitting antenna combination set that can maximize the capacity lower bound β:

Among them, S represents the set of all antenna selection schemes that meet the requirements, [R _i , C _Rj ] represents an antenna selection scheme, Indicates the final selected receive antenna combination and transmit antenna combination set.

The beneficial effect of the present invention is that the present invention provides a method for selecting transceiver antennas of a generalized spatial modulation system based on system capacity. This technology selects a suitable set of transceiver antennas according to channel information, so that the capacity of the system is significantly improved. The system can improve the BER performance of the system under the condition of introducing less amount of feedback and increasing the complexity of the system.

Description of drawings

Fig. 1 is a traditional GSM system block diagram;

Fig. 2 is a system block diagram of the antenna selection method at the transceiver end based on the generalized spatial modulation system proposed by the present invention.

detailed description

Below in conjunction with accompanying drawing, describe technical scheme of the present invention in detail:

In order to better describe the present invention, the terms used in the technical solution of the present invention and the transmitter structure of the generalized spatial modulation system are introduced here.

Generalized spatial modulation: Assuming that the GSM-MIMO system has N _t transmitting antennas and N _r receiving antennas, the transmitting end of each time slot only selects N _p (N _p <N _t ) transmitting antennas to send data symbols. Since the combination of selecting N _p antennas among the N _t transmitting antennas has a total of , according to the bitmap rule, only need Antenna combinations are used for the mapping of information bits, Indicates rounding down. Therefore, similar to traditional spatial modulation, the information bits to be transmitted are divided into two parts, one part is used to select the combination of transmitting antennas, and the required bit length is The other part is used to select the APM constellation symbol The required bit length is l ₂ =log ₂ (M), where M is the modulation order, Represents a collection of APM constellation symbols. Let the transmitted information bit vector be b and the length be L, then After selecting the transmitting antenna combination and the APM constellation point according to the transmitted information bits, the transmitting antennas in the combination are activated and the symbol s is transmitted at the same time, while the rest of the antennas not in the selected combination remain silent and do not transmit any signal.

As shown in Figure 1, b is the bit data to be transmitted, which can be regarded as an L×T matrix, where L=log2(M)+2*log2(Mary) is the number of bits carried by a GSM modulation symbol, and Mary is Quadrature Amplitude Modulation (Quadrature Amplitude Modulation, QAM) order, T represents the number of time slots. The number of bits that a GSM modulation symbol can carry is determined by the QAM modulation order and the number of transmit antenna combinations. The GSM modulation criterion is to convert b into an M×T matrix x according to the GSM conversion table. In x, one column represents the data sent at one time, and any column has only Ns non-zero data of the number of antennas in each antenna combination, which means that only the antennas of the selected combination send data at any time.

The specific embodiment of the present invention is a system diagram as shown in FIG. 2 .

The transmitter structure is roughly divided into the following steps:

Step 1: Determine the parameters of the system to be selected, that is, determine the number of transmitting antennas N _t , the number of receiving antennas N _r , the number of transmitting antennas activated each time N _s , the number of activated transmitting antenna groups to be selected is N _ts , The mean value of the QAM symbol modulation order is m, according to

Step 2: Obtain the receiving antenna set and the transmitting antenna combination set by using the method in the summary of the invention;

Step 3: Use the above steps to select a combined set of receiving antennas and transmitting antennas for information transmission.

Claims (1)

1. The generalized spatial modulation system transceiver antenna selection method based on system capacity defines that each receiving antenna combination in the generalized spatial modulation system includes N _rs root receiving antennas, and each transmitting antenna combination includes N _ts root transmitting antennas, Each transmit antenna combination set contains m transmit antenna combinations, and m is a power of 2. The purpose of this method is to select the receive antenna combination {R ₁ ...R _n } and the transmit antenna combination set {C _R1 ...C _Rm } The target combination [R _i , C _Rj ] in is characterized in that it includes the following steps: a. Obtain the capacity lower bound β _ij of the GSM system composed of each receiving antenna combination R _i and a group of transmitting antenna combination sets C _Rj : <mrow><msub><mi>&amp;beta;</mi><mrow><mi>i</mi><mi>j</mi></mrow></msub><mo>=</mo><mfrac><mn>1</mn><mi>m</mi></mfrac><msubsup><mi>&amp;Sigma;</mi><mrow><mi>k</mi><mo>=</mo><mn>1</mn></mrow><mi>m</mi></msubsup><msub><mi>log</mi><mn>2</mn></msub><mi>det</mi><mrow><mo>(</mo><msub><mi>I</mi><msub><mi>N</mi><mrow><mi>t</mi><mi>s</mi></mrow></msub></msub><mo>+</mo><mfrac><mi>&amp;rho;</mi><msub><mi>N</mi><mrow><mi>i</mi><mi>s</mi></mrow></msub></mfrac><msub><mi>H</mi><mi>k</mi></msub><msubsup><mi>H</mi><mi>k</mi><mi>H</mi></msubsup><mo>)</mo></mrow></mrow> Among them, H _k represents the channel matrix formed by the kth transmitting antenna combination under the antenna combination, Represents a unit square matrix of size N _ts , ρ represents the signal-to-noise ratio; b. Select the receiving antenna combination and transmitting antenna combination set that can maximize the capacity lower bound β: <mrow><munder><mrow><mover><mi>s</mi><mo>^</mo></mover><mo>=</mo><mi>arg</mi><mi></mi><mi>max</mi></mrow><mrow><mo>&amp;lsqb;</mo><msub><mi>R</mi><mi>i</mi></msub><mo>,</mo><msub><mi>C</mi><mrow><mi>R</mi><mi>j</mi></mrow></msub><mo>&amp;rsqb;</mo><mo>&amp;Element;</mo><mi>S</mi></mrow></munder><mrow><mo>(</mo><msub><mi>&amp;beta;</mi><mi>i</mi></msub><mo>)</mo></mrow></mrow> Among them, S represents the set of all antenna selection schemes that meet the requirements, [R _i , C _Rj ] represents an antenna selection scheme, Indicates the final selected receive antenna combination and transmit antenna combination set.