Differential orthogonal space-time block codes for four transmit antennas

Abstract

A new high-order differential space-time block code (DSTBC) is introduced as an attractive alternative to the well-known coherent spacetime block code (STBC) by providing both full space-time diversity and blind detection. A differential detection based on the orthogonal STBC scheme is proposed. The proposed differential scheme is a generalisation of the recent DSTBC already designed for two transmit antennas. The proposed differential encoder consists of a specific trellis diagram that creates a positive correlation between successive differential data. At the receiver side, the well-known Viterbi algorithm is applied using a specific metric that nearly compensates for the 3 dB penalty commonly introduced by the symbol by symbol differential schema, and shows a 0.5 dB performance loss only from the coherent STBC scheme. © 2014 The Institution of Engineering and Technology.