Applying a New Constellation Rearrangement (CoRe) in Time/Frequency in MIMO Antenna Systems
The use of a unique bit-to-symbol mapping for each diversity branch (often referred to as constellation rearrangement) is known to provide good performance for higher level linear modulation techniques when used in conjunction with Orthogonal Transmit Diversity (OTD) and Automatic Repeat reQuest (ARQ). This paper investigates the performance of Constellation Rearrangement (CoRe) scheme when used in conjunction with spacetime/ frequency system. The idea is to use optimized constellation so that minimum Squared Euclidean Distance (SED) between different branches is maximized. The authors get three fold gain from this scheme; time/frequency diversity by transmitting data in different time/frequency slots and spatial diversity by using multiple antennas at transmitter and receiver and performance gain by using CoRe.