连续相位调制和Turbo乘积码的串行级联系统设计

The Design of Serial Concatenated System of Turbo ProductCode with Continuous Phase Modulation

针对Turbo乘积码(TPC)与递归连续相位调制(CPM)级联系统(TPC-RCPM)误码性能差的问题,提出了一种由Turbo乘积码、伪随机交织器和非递归CPM组成的串行级联系统.首先将输入数据进行TPC编码,并对编码序列进行随机交织,然后送至非递归CPM调制器,经过非递归连续相位编码后与转换矩阵相乘,经无记忆调制器输出映射波形.与其他TPC-CPM系统相比,该系统的调制参数能够灵活调整,可以充分弱化解调器的错误相关性,改善系统的误码性能.仿真结果表明,与TPC-RCPM系统相比,该系统有效地降低了误码率,对于MSK和4CPM信号,在误比特率为10-2～10-5时可以获得约2.2dB和2dB的信噪比增益.

A new design scheme of serial concatenated system is proposed to solve the problem of poor bit error performance of concatenated Turbo product code（TPC） with recursive continuous phase modulation（CPM）（TPC-RCPM）.The scheme is composed of Turbo product code,random interleaver and non-recursive continuous phase modulation.Firstly,the input data are encoded by TPC encoder,and the encoded bits are then interleaved and put into non-recursive continuous phase modulator.The bits inputted to the non-recursive CPM are encoded by a non-recursive continuous phase encoder,and the outputs from the encoder are multiplied by a conversion matrix.Then,mapping waveforms are output through a memoryless modulator.Compared with other TPC-CPM systems,the proposed scheme has good flexibility for inner code parameter adjustment.The proposed scheme can greatly weaken the error correlation in the demodulator,leading to better BER performance.Simulation results show that the proposed scheme is effective in reducing BER compared with TPC-RCPM system.For MSK and 4CPM signals,about 2.2 dB and 2 dB SNR improvement are obtained when BER is in the range from 10-2 to 10-5.