Research On Performance Of STBC-OFDM Systems Over HF Watterson Channel

HF communication is one of the primary means of long distance communication. In recent years, because of its small transmission power and strong ability of anti-interference, it is widely used in various communication fields. At present, improving transmission rate in communication systems is one of the main fields of research in the HF communication. Meanwhile, the space-time coding technology has also been extensively studied to increase the channel capacity of effective technology.This paper proposes an idea of which space-time coding technology is applied to HF communication. However, space-time coding technology is only applicable to flat fading channel. Given the HF channel characteristics, the paper introduces the orthogonal frequency division multiplexing (OFDM). Orthogonal frequency division multiplexing with strong anti-fading characteristics can convert frequency selective fading to flat fading. Thus the communication will achieve very good results with STBC-OFDM.This paper firstly introduces multipath delay and fading properties of the HF channel. Secondly we have constructed the Watterson model and implemented the simulation model of HF channel. Then, we describes the basic principles of space-time block code (STBC)and different space-time block code encoding and decoding methods given the flat fading channel simulation of BER performance of STBC results. Last we describe the principle of OFDM technology, and simulate the performance of STBC-OFDM systems. On this basis, we analyze the performance of STBC-OFDM systems over HF channel and construct the system and signal model, and then give the simulation results and conclusion. The results of simulation show that STBC-OFDM system can make full use of spectrum resources for lower bit error rate and it can improve the communication system performance to achieve HF communications requirements.