摘要
在一个未经信道编码的M-PSK/DPSK数字通信系统中,M-DPSK信号非相干解调比M-PSK信号相干解调要损失3 dB的信噪比,该情况同样出现在采用卷积信道编码的系统中.为了提高差分调制系统的性能,从级联编码的角度分析卷积编码、M-DPSK调制系统,采用Turbo算法实现对级联编码信号的接收.仿真结果显示,Turbo算法得到了比SOVA算法多3.5 dB的增益.在小BER情况下,M-DPSK信号Turbo接收的性能好于M-PSK信号SISO译码.这种Turbo迭代思想也适用于具有类似级联编码结构系统的译码.
In an uncoded digital transmission system with M-PSK or M-DPSK, there exist 3dB more SNR loss in MDPSK noncoherent demodulation than in M-PSK coherent demodulation. This difference remains in the system with convolutional codes as channel coding. In order to improve the performance of differential modulation system, an approach is put forward, whereby the transmitter is regarded as a concatenated encoding system and a Turbo receiver is used to decode the signal. Turbo decoding obtains small BER, the performance of M-DPSK Turbo decoding to the system with concatenated encoding 3.5 dB more gain than SOVA algorithm. In the case of is better than M-PSK SISO decoding. This method also fits
出处
《应用科技》
CAS
2006年第6期57-59,共3页
Applied Science and Technology
