基于旋转矩阵的差分酉空时编码调制

针对传统的差分酉空时编码调制在高信噪比(大于10dB)时,性能仍不理想的问题,引入旋转矩阵思想,提出了一种新的差分酉空时调制星座图的设计方法.该方法设计的非群星座图,比传统的循环群码有更大的分集乘积,因而理论上有更好的性能.同时可以通过对该方法进行简化来降低计算复杂度:当星座图的大小为偶数时,该算法可以简化为3个参数.仿真结果表明,在BER(Bit Error Rate)为10-4的情况下,用新提出的方法设计的差分酉空时码的性能比循环酉空时码的性能要好近1dB.

Differential Unitary Space-Time Modulation Based on Rotation Matrix

The performance of traditional differential unitary space-time coding is still imperfect in high signal-to-noise ratio (larger than 10 dB). A new design method of differential unitary space-time constellation is introduced. This method is based on rotation matrix. The non-group constellation designed by the proposed method will have a larger diversity product than the constellation designed by conventional cyclic group code. So it will have a better performance in theory. This proposed method could also be reduced to lesser computational complexity. When the size of the constellation is even, the number of the optimized parameter can be reduced to 3. The simulation results show that the performance of the proposed code is about 1 dB better than cyclic unitary code at BER(Bit Error Rate) is 10~(-4).