On the performance analysis of asynchronous FH-SSMA communications

Multiuser demodulation and iterative decoding for frequency-hopped networks

Demodulation and decoding for frequency-hopped spread-spectrum multiple-access (FH/SSMA) systems have been traditionally conducted by conventional single-user (noncollaborative) demodulation and errors and erasures correcting decoding techniques. In this paper, we study the demodulation and decoding aspects of collaborative multiuser reception for FH/SSMA and propose methods which increase the ...

Partial successive interference cancellation in hybrid DS/FH spread-spectrum multiple-access systems

Partial successive interference cancellation is considered in hybrid DS/FH spread-spectrum multiple-access (SSMA) systems. We first show that the lowest BER attained by employing full interference cancellation in DS/SSMA systems can almost be achieved by employing a partial interference cancellation in hybrid DS/FH systems. The reduction in the number of cancellations translates into an allevia...

Turbo Codes with Channel Estimation and Dynamic Power Allocation for Anti-Jam FH/SSMA *

In this paper we study the performance of turbo codes infrequency-hopped spread spectrum multiple access networks (FH/SSMA). An iterative scheme for estimating the log likelihood ratio of the channel output is proposed. This scheme is compared with other techniques that provide tradeoffs between simplicity of implementation, BER performance, and robustness to channel variations. Based on the es...

Multireception probabilities for FH/SSMA communications

Performance of UWB SSMA using orthogonal PPM-TH over dense multipath channels

In this work we study ultra wideband (UWB) communications over dense multipath channels using orthogonal pulse position modulation (PPM) for data modulation and time-hopping (TH) for code modulation. We consider the effects of the multiple access interference (MUI) in asynchronous spread spectrum multiple access (SSMA) based on random TH codes. We use a realistic multipath channel to analyze th...