Rate 2 Quasi-Orthogonal Space Time Block Codes using Parallel Interference Cancellation
In this paper, we focus on an advanced space-time system using a rate 2 quasi-orthogonal space-time block code which enables us to achieve very good performance for an overall throughput of up to 4.3 bits/s/Hz. This is done through the use of a bit-mapped coded modulation structure using short low density parity check component codes. At the receiver, parallel interference cancellation (PIC) and belief propagation (BP) decoding are employed. Iterative decoding is performed between the PIC and BP decoding stages. Given a fixed total number of decoding iterations, we investigate the frequency of PIC updates required to achieve good performance.