基于可靠度的连续相位软解调算法及仿真  

Reliability-Based Soft Demodulating Algorithm for CPM and its Simulation Results

作　　者：杨勇 张凯 

机构地区：[1]西安烽火电子科技有限责任公司,陕西西安710075

出　　处：《无线电通信技术》2015年第6期46-49,共4页Radio Communications Technology

摘　　要：连续相位调制具有频谱利用率高、较低的带外功率、信号恒包络等特性,广泛地应用于无线通信系统中。然而现有的基于概率域的解调算法复杂度较高,不具有实用价值。针对这一问题对高效的相位连续调制技术进行了详细讨论,进而提出了基于可靠度的低复杂度CPM软解调算法。提出的软解调算法计算接收信号与调制信号之间的相关值,并将其作为信息度量。算法不依赖于信道噪声方差,避免了信道噪声方差估计不准确对解调性能带来的影响。仿真结果表明,提出的基于可靠度的软解调算法的性能与概率域下的解调算法几乎没有差异,并且完全能够与现代纠错码相结合,从而提高通信系统的可靠性。Continuous-Phase Modulation has been widely used in different communication systems due to the advantages like high spectrum utilization,low side-lobe power and constant envelope. However the probabilistic demodulating algorithm for CPM has high computational complexity and is not adaptive to practice.For this problem, the CPM technology is discussed,and further a reliability- based soft demodulating algorithm for CPM is proposed. The proposed reliability-based demodulating algorithm takes the mutual correlation between received signal and modulated signal as information metric. The algorithm is independent of variance of channel noise,which avoiding the effect of inaccurate estimate of channel. Simulation results show that, the reliability-based demodulating algorithm performs as well as the probabilistic demodulating algorithm,and can be combined with LDPC codes to improve the reliability of communication system.

关 键 词：连续相位调制 前向纠错码 格图 可靠度信息 

分 类 号：TN76[电子电信—电路与系统]