多径信道中OFDM系统的优化设计

Design of Optimized OFDM System in Multipath Channel

多径衰落是多径信道中存在的最大问题。连续相位调制正交频分复用信号(OFDM-CPM)是一种将连续相位调制技术(CPM)应用于正交频分复用(OFDM)系统的新思路,它具有良好的相位平滑转移特性、较高的频带利用率和较低的误码率,它可以有效提高系统的抗多径衰落能力和信道利用率。在多径信道中,对OFDM-CPM信号进行了研究并详细推导出了该系统的数学模型。仿真结果显示,该信号具有比OFDM-PSK信号更优秀的误码率(BER)表现,因此证明了该思路的有效性和可行性。

Muhipath fading is a most important problem in mhipath channel. Orthogonal Frequency Division Multiplexing - Continuous Phase Modulation （OFDM - CPM） signal is a new method of using CPM on OFDM. This method has smooth phase transferring characteristic, higher channel utilization and lower Bit Error Rate （BER）. Therefor, it has better capability of coping with multipath fading and higher channel utilization. In multipath channel, the paper studies OFDM - CPM and deduces the mathematics model. Then, many simulations are made. The simulation results show that OFDM - CPM signal has lower BER than OFDM - PSK signal and demonstrates that the new method is effective and feasible.