Multi-access interference cancellation receiver for time-hopping ultra wideband communication

In this paper, a low complexity coherent joint maximum-likelihood detection receiver is developed for canceling multi-access interference in impulse radio (IR) based ultra wideband (UWB) wireless communication systems. Unlike previous joint demodulation receivers, where the complexity is enormous and the other users' codes are required, the proposed approach does not need to know the time hopping (TH) codes of the other users which makes it a very attractive solution. The performance of joint demodulation receiver depends on the ability to estimate the channel coefficients of desired and interfering users. A novel and practical algorithm for estimating multiple users' channel responses is developed. The performance of the proposed algorithms are tested through computer simulations and the results are compared with the performance of the conventional single user UWB receiver. It is observed that the proposed joint demodulation receiver provides significant performance gains with respect to conventional single user receiver.