Golden Codeword Based Generalized Differential Alamouti Modulation

Conventional differential modulation is capable of performing detection without knowledge of the channel state information at the receiver. However, it suffers a 3 dB error performance penalty as compared to its coherent counterparts. Generalized differential modulation has been proposed to improve error performance compared to the conventional differential modulation. In this paper, we investigate the generalized differential Alamouti modulation (GD-Alamouti), and then propose Golden codeword based generalized differential Alamouti modulation (GC-GD-Alamouti), which achieves equivalent space diversity. We then propose two detection schemes: a near-maximum likelihood detection and a low-complexity detection for the proposed GC-GD-Alamouti. The detection complexity for the two proposed detection schemes is analyzed. Finally, we derive the average symbol error probability for both GD-Alamouti and GC-GD-Alamouti modulation. Both simulation and theoretical results show that the proposed GC-GD-Alamouti modulation improves error performance compared to the GD-Alamouti modulation. For example, the GC-GD-Alamouti modulation with two receive antennas achieves approximately 2.8 dB at an average symbol error rate of 3 × 10
^-5
.