基于空时分组码的差分调制

Differential Modulation Based on Space-Time Block Codes

提出了基于空时分组码的差分调制方案,该方案具有较低的计算复杂性,且具有更加简化的译码器.在3个、4个发射天线的情况下具有更高的速率,对给定速率而言,有更高的编码增益和更低的误比特率,并对3个、4个发射天线的情况进行了仿真.仿真结果表明,用3个发射天线和1个接收天线且码速率为3bits/(s·Hz-1)时,差分STBC要比差分群码方法优越5dB;用4个发射天线和1个接收天线且码速率为3bits/(s·Hz-1)时,差分STBC要比差分群码方法优越6.5dB.表明本文提出的方法具有更高的误比特率性能.

A differential modulation scheme using spacetime block codes was put forward. Compared with other schemes, it has a lower computational complexity and a simpler decoder. In the case of three or four transmitter antennas, it has a higher rate and for a given rate has a higher coding gain and a lower bit error probability. The simulation was made for spacetime block codes as well as group codes in the case of two, three, four and five transmit antennas. The results prove that using three transmit antennas, one receive antenna and code rate of 3 bits/(s·Hz-1), the differential STBC method outperforms the differential group codes method by 5 dB. When using four transmit antennas, one receive antenna, and code rate of 3 bits/(s·Hz-1), the differential STBC method outperforms the differential group codes method by 6.5 dB. In other words, the differnetial modulation scheme based on spacetime block code is better than the corresponding differential modulation scheme.