Abstract: This paper presents a new space-time block code, which introduces orthogonal spreading sequences to the basic structure of the space-time block code, and a blind decoding system, which carries out the decoding without the estimation of the channel. Combined with the orthogonal character of spreading sequences and the orthogonal structure of space-time block code, the noise subspace of the received signal are exploited to achieve the decoding without a knowledge of the channel. Simulation results show that the new space-time block code has good performance at the word error rate (WER) and the bit error ratge(BER).

Key words: space-time block code, orthogonal spreading sequence, subspace method, blind decoding