Spatial diversity with a new sequential maximal ratio combining over wireless fading channels

A new spatial diversity with sequential maximal ratio combining (S-MRC) is proposed and analyzed. In the S-MRC system, the diversity branches are added for combining one-by-one in a sequential manner, and a truncated sequential probability ratio test (TSPRT) is used for signal detection. By sequentially adding individual branches for combining, the power consumption from directly using all available branches can be saved. The S-MRC is more power-saving than the traditional MRC or the output-threshold MRC (OT-MRC). Numerical results for the bit error rate (BER) of the BPSK signaling over the independently and identically distributed (i.i.d.) Rayleigh fading channels are presented to illustrate the performance of the S-MRC which is much better than the OT-MRC and is identical to that of the traditional MRC if a suitable test threshold is used. Furthermore, the average number of active branches is much smaller than that of the traditional MRC.