A new full-rate orthogonal space-time block coding scheme based on quaternion

This paper introduces a full rate, full diversity orthogonal space-time block code for 4 transmit antennas. The 4 x 4 codeword matrix consists of four 2 x 2 Alamoud blocks, and these blocks can be viewed as quaternions which in turn represent rotations in R-3. The Alamouti blocks that appear in a codeword are drawn from the icosahedral group. The code is no constellation expansion unlike some full-rate full-diversity codes in the literature By utilizing the quaternionic form, we can find the decoding algorithm to reduce the complexity of maximum likelihood (ML) coherent decoding.