基于高性能编码调制映射的联合解调译码方法

A Joint Demodulation and Decoding Method Based on High-Performance Code-Modulation Mapping

对于功率受限的加性高斯白噪声(Additive White Gaussian Noise,AWGN)信道,当具有高斯分布的信号作为信道输入时,信息传输性能接近信道容量.为了传输性能接近容量限,本文采用优化的非均匀排布APSK(Amplitude Phase Shift Keying)星座取代传统的多维QAM(Quadrature Amplitude Modulation)调制星座图,利用二进制交换算法(Binary Switching Algorithm,BSA)进行星座图的反馈后哈姆尼克均值优化,设计了一种新型的"4+12F-APSK"非均匀排布的星座映射方案,并与BICM-ID(Bit Interleaved Coded Modulation-Iterative Decoding)解调译码相结合,提出了基于高性能编码调制映射的联合解调译码方法,有效地解决了接近信道容量限的联合解调译码的难题.实验结果表明,在瑞利衰落信道误比特率在10的-5次方量级时,该方法比传统的MSEW(Maximum Squared Euclidean Weight),GRAY,SP(Set Partitioning)三种矩形QAM调制方案的译码性能至少改善0. 6dB;在AWGN信道误比特率在10的-3次方量级时,该方法比传统的MSEW和GRAY映射至少改善0. 3dB.同时,与其他16APSK映射方案相比,该方法无论是在瑞丽衰落信道还是在AWGN信道条件下,在相同的误比特率量级上,都具有1dB～2dB的译码性能增益,有效地逼近了传输容量限.该方法在移动通信和电视广播通信等资源有限网络中具有广泛的应用前景.

Over a power-limited additive white Gaussian noise channel(AWGN),the transmission performance can achieve the channel capacity when the input follows Gaussian distribution.Therefore,this paper found a promising ununiform-APSK(Amplitude Phase Shift Keying)constellation mapping“4+12F-APSK”which is optimized by the binary switching algorithm(BSA)using Harmonic mean after feedback to be the cost function,and presented a joint demodulation and decoding method based on high-performance code-modulation mapping to approach the channel capacity efficiently.In BICM-ID(Bit Interleaved Coded Modulation-Iterative Decoding),simulation results show that,in Rayleigh fading channel at BER(Bit Error Rate)of ten to the negative five,the proposed method outperforms the traditional rectangle 16QAM(Quadrature Amplitude Modulation)mapping as MESW(Maximum Squared Euclidean Weight),GRAY and SP(Set Partitioning)by 0.6dB at least;in AWGN channel at BER of ten to the negative three,this number is 0.3dB compared with MSEW and GRAY mapping.Moreover,both in Rayleigh and AWGN channels,the proposed method has 1dB^2dB performance gain compared with the other ununiform-16APSK mappings.It has a wide range of applications in resource limited networks such as mobile and broadcast communication.