摘要
对低密度奇偶校验码(LDPC)在QPSK调制下的对数似然比(LLR)算法进行了深入研究,分析了LDPC码在QPSK调制下初始消息的计算方法,推导了初始消息的计算公式。同时对该算法进行了程序仿真,仿真结果表明LDPC码在QPSK调制中具有良好的性能。当信噪比为3.5 dB时,误码率可达到10-6数量级。
The Log-Likelihood Ratio （LLR） algorithm of Low-Density Parity-Check Codes （LDPC） under the Quadri Phase-Shift Keying （QPSK） modulation was studied. The initial information computation method of LDPC under QPSK modulation was analyzed. And the formulas of initial information were deduced in detail. Simulations were made for the algorithm and the result showed that the decoding performance of LDPC is fine under QPSK modulation. For example, the Bit Error Rate （BER） can reach 10^-6 at 3.5 dB SNR.
出处
《电光与控制》
北大核心
2010年第4期90-92,共3页
Electronics Optics & Control
关键词
低密度奇偶校验码(LDPC)
QPSK
调制
Low-Density Parity-Check Codes （LDPC）
Quadri Phase-Shift Keying （QPSK）
modulation
