Multiple phase detector of M-ary phase shift keying symbols in code division multiple access systems

A novel iterative technique,the phase descent search(PDS) algorithm,for M-ary phase shift keying(M-PSK) symbols detection was proposed.This technique constrained the solution to have a unit magnitude and it was based on coordinate descent iterations where coordinates were the unknown symbol phases.The PDS algorithm,together with a descent local search(also implemented as a version of the PDS algorithm),was used multiple times with different initializations in a proposed multiple phase detector;the solution with the minimum cost was then chosen as the final solution.The simulation results show that for highly loaded multiuser scenarios,the proposed technique has a detection performance that is close to the single-user bound.The results also show that the multiple phase detector allows detection in highly overloaded scenarios and it exhibits near-far resistance.In particular,the detector has a performance that is significantly better,and complexity that is significantly lower,than that of the detector based on semi-definite relaxation.