Research And Implementation On Stbc And Frequency Domain Equali-Zation In MIMO SC-FDE System

In the rapid development of communication technology today,people are increasingly demanding the wireless communication rate. Thefifth generation communication technology (5G) is proposed to reach the peak rate of 20Gbps target. The multiple-input multiple-output (MIMO)technology based on antenna diversity and smart antenna technology can increase the capacity and spectrum utilization of communication system by several times without increasing the bandwidth. In order to fully exploit the potential coding gain and diversity gain of MIMO technology,the design of space-time code is very important. The space-time block coding (STBC) can use the low complexity of the decoding algorithm to obtain the maximum spatial diversity gain and it has been widely used.And frequency domain equalization technology is the main equalization technology in wireless communication. So it is necessary to research and implement space-time coding and frequency domain equalization in MIMO systems.In this paper, we firstly analyzed the principle of STBC coding and decoding theoretically and give the derivation of maximum likelihood decoding algorithm. At the same time, the equalization criterion of forcing zero and minimum mean square error (MMSE) are analyzed. The MMSE equalization criterion is analyzed in detail from the frequency domain perspective. A MIMO SC-FDE system with low SNR is designed for the special application scenario, and the performance simulation results are given.Frequency domain equalization algorithm can not be implemented in hardware without FFT processor and the hot OFDM technology is based on FFT transform. Taking into account the localization of related equipment, in this paper, an FFT processor is designed, which can save the resources most under the condition of satisfying the delay requirement.At last, the STBC and frequency domain equalization algorithms are designed and implemented using FPGA as a platform, and integrated into the whole system for indoor test and field test, and achieved good results.The result of indoor test and field test shows that combining STBC technology with SC-FDE technology can fully obtain diversity gain and combat inter-symbol interference. The improved STBC decoding algorithm is very suitable for combining with the frequency domain equalization, which reduces the complexity of the algorithm and is beneficial to the realization of FPGA. Through continuous optimization and improvement, the whole system has achieved a good test results, with a certain practical value of the project.