Subspace-based blind joint detection of fading, asynchronous cochannel TDMA signals

We consider joint detection of asynchronous cochannel signals with an antenna array in Rayleigh fading. No training sequences are assumed, so detection is blind. By exploiting the eigenstructure of the array matrix, we associate the high-order modes with time-varying channels of different polynomial order. When the time variation of the channels is piecewise linear over an appropriately selected detector window, our new algorithm-subspace blind joint detection, or SBJD-is able to simultaneously distinguish the asynchronous co-channel signals and estimate the Rayleigh channels (within a phase factor)