Performance Bound for LDPC Coded Unitary Space-Time Modulation

This paper is concerned with the bit error probability (BEP) of coded unitary space-time modulation systems based on finite-length low density parity check (LDPC) codes. The union bound on the BEP is derived for any code rate, unitary space-time constellation and mapping. The tightness of the bound is verified with simulation results of the ordered statistic decoding (OSD). Numerical and simulation results show that the union bound is also close to the error performance of the sum-product decoding at the low bit error probability (BEP) levels when Gray mapping is employed. The derived bound is useful to benchmark the error performance of LDPC coded unitary space-time modulation systems.