Space-Time Codes With Block-Orthogonal Structure and Their Simplified ML and Near-ML Decoding
Existing high-rate full diversity Space-Time Codes (STC) always have high decoding complexity with traditional ML (maximum-likelihood) or near-ML decoding. Hence the decoding scheme with reduced complexity is required. In this paper, block-orthogonal structure is introduced for the first time, and most of the existing STC do have such structure. A simplified decoding is proposed to exploit the block-orthogonal structure of the code and reduce the complexity drastically without any extra loss in decoding performance. To achieve diversity and spatial multiplexing gains in multi-antenna systems, high-rate Space-Time Codes (STC) have become an essential part of broadband wireless communication systems such as the IEEE 802.16e-2005 standard.