On hard and soft detection of space-time block codes by a novel soft output sphere decoder

A new soft detector for space-time block codes (STBCs) is proposed, which is claimed to be more efficient than existing techniques. This tool has been used to compare four STBCs: 1) Alamouti, 2) rotated and scaled Alamouti, 3) Golden and 4) tilted QAM. We evaluate the performance in uncoded and low-density parity-check coded (LDPC) scenario and we stress the difference between the two cases.