Multistage decision feedback channel estimation for DS/CDMA systems with M-ary orthogonal modulation

In [3], the decision feedback channel estimation (DFCE) for M-ary orthogona l modulation in direct sequence/code division multiple access (DS/CDMA) sys tems was proposed. However, the performance of the DFCE in the multiuser en vironment is severely degraded due tu multiple access interference (MAI), I n this letter, to overcome this problem, we modify the DFCE as multistage c onfigurations using a multistage parallel interference cancellation (PIC) s cheme. According to the result of our simulations, the performance of coher ent demodulation using the proposed multistage DFCE is significantly improv ed in comparison with conventional demodulation in [3].