| With the development of information technology, people have put forward higher and higher request to the data transmission rate and transmission reliability of wireless communication. Although the MIMO system has been put forward to a certain extent, it has met the demand of the system performance, but it has greatly increased the complexity and energy consumption of the system. In order to reduce the complexity and energy consumption of large scale MIMO system, a new multi antenna spatial multiplexing technique, namely spatial modulation technique, is proposed in the last few years.Spatial modulation technology at any time only activate a transmit antenna, so the system structure at the transmitter does not need to synchronize between the antenna, in the receiver to detect and demodulation is relatively simple. At the same time, it also uses the serial number of the antenna to transmit information, thus eliminating the part of power, so compared with the traditional multi antenna technology, spatial modulation technology is relatively high. But the spatial modulation system requires that the number of antennas at the transmitter end is 2power, and the data transmission rate is lower than that of the large scale MIMO system. So, this paper proposes a at the transmitter to transmit antennas are grouped by spatial modulation system, by performing the Linear Precoding processing at the transmitter. It can not only break the emission antenna number is 2 to the power of the constraints, but also improves the data transmission rate, reduce complexity of the demodulation receiving. In this paper, the zero forcing(ZF) precoding and minimum mean square error(MMSE) precoding techniques, to antenna grouping of spatial modulation system performance based on the analysis, obtained the closed form expression for the bit error rate(BER) to optimize the system transmission rate.The main contents are as follows:1, At the transmitter, first of all on the base station transmitting antenna grouping so as to improve the data transmission rate of the wireless system, and then use the spatial modulation system at any time there is only one antenna work and the rest ofthe other transmit antennas are not working, the spatial modulation of a complex MIMO wireless communication system channel matrix is simplified into a only the dimension of the vector matrix. This simplifies the calculation process.2, The mathematics of the chi square distribution approximation of distribution are obtained by using the method of forcing zero linear precoder bit error rate and the were simulated and analyzed. The results show that the approximate results and the simulation results are very close to the. Finally, the effect of the number of K, the number of M in the receiver and the number of users on the transmitter is analyzed,and how to adjust these parameters to improve the performance of the system is also analyzed.3, Using the same theory is calculated approximately by using minimum mean square error linear precode space modulation system BER, and then the simulation analysis and find out the theoretical approximation is very close to the simulation results. Through to both linear precoder simulation analysis, it is found that, when the receiving end user number m is constant, an appropriate increase in emission antenna grouping number k can improve the BER performance of the system.4, The transmission performance of the antenna grouping space modulation system is analyzed, and the optimization of the system is also carried out. When each group has two antennas, its transmission rate is the largest. Finally, the system transmission rate is analyzed, and the simulation results show that the analysis is correct, and it is superior to the traditional SM and GSM transmission performance. |
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