Low-Complexity Decoding Scheme for $1\times K$ Differential Space-Time Line Coded System With $M$-PSK Modulation

This study considers a $1\times K$ differential space-time line coded system with one transmit antenna and $K$ receive antennas. A conventional joint maximum likelihood (ML) detection method requires a computational complexity order of $\mathcal {O}(KM^{2})$ for the $M$-phase-shift keying symbols. By decomposing the joint ML into two individual ML detections and bounding the $M$ search constellation points by three regardless of modulation size, the proposed bounded ML detection can significantly reduce computational complexity to $\mathcal {O}(K)$. The numerical results verify that the complexity reduction of the proposed detection method can be obtained without compromising any bit-error-rate performance.