基于LDPC编码的交织多址接入(IDMA)系统

交织多址接入（IDMA）技术是第四代移动通信的关键技术之一,为了使该系统更加接近多址接入的信道容量限，设计了一种基于LDPC码编码的交织多址接入（IDMA）系统，并将它与传统的基于卷积码编码的IDMA系统在高斯白噪声(AWGN)信道下进行了性能比较。仿真结果发现，随着信噪比的增加，该系统的多用户性能曲线会逐渐向单用户性能曲线靠近；16个用户时该系统在误比特率为10-6情况下离多址接入的信道容量限大约是2.6 dB，而相同条件下，基于卷积码编码的系统大约是6.0 dB。清楚地表明：设计的系统更加接近多址接入的信道容量限，可以获得更多的编码增益。在实际应用中，非常适合于高速的数据传输业务。

Interleave division multiple access system using LDPC codes

IDMA is one of key technologies in the fourth generation of mobile telecommunication. For making it closer to the multiple access channel (MAC) capacity limits, an IDMA system based on LDPC codes is presented. Based on the performance comparision between the purposed system and the Convolutional Coded IDMA systems over AWGN Channel, it has been found that, with the SNR increased, performance curves of this system with multi users are close to that with single user gradually; performance of it with 16 users is about 2.6 dB away from the MAC capacity limits at the bit error rate of 10-6, but that of the traditional systems is about 6.0dB away in the same condition .It is obvious that the designed system is closer to the MAC capacity limits, and can obtain more coding gains. In practical application, it is very suitable for high speed transmission operation.