高速短波OFDM系统空间分集接收性能仿真分析

Simulation of spatial diversity reception performance of high-speed HF OFDM system

为了解决现有窄带短波通信系统存在的速率低、误码率高等问题，基于正交频分复用技术和空间分集接收技术，提出了一种可用性高的窄带短波高速数字系统．该系统在发射端采用多进制正交振幅调制和信道编码交织，在接收端采用信道估计和分集接收技术，从而有效降低了系统误码率．仿真结果表明，当短波系统传输速率为9.6 kb/s 时，在采用多天线分集接收技术之后，与国外同类典型研究结果相比，多天线分集技术有3~6dB的增益，这说明多天线分集技术提升了短波系统的性能，使得系统达到了可用性要求．

In order to solve the problem of low data rate and high bit-error-rate (BER) in the existingnarrowband shortwave communication system, this paper presents a narrowband shortwave high speed digitalsystem with high availability, based on orthogonal frequency division multiplexing (OFDM) and spatial diversityreceiving technology. The multi-system quadrature amplitude modulation and channel coding interleaving areemployed at the transmitter in this proposed system, and the channel estimation and diversity reception techniquesare used at the receiver in the system, thus reducing the system’s BER effectively. Simulation results show thatusing the multiple antenna diversity reception is to have a gain of 3-6 dB when the transmission rate of thisshortwave system is 9.6 kb/s, compared with the same type of research results overseas. It is suggested that themultiple antennas diversity technology can improve the shortwave system performance, allowing the system tomeet the requirement of availability.