Transform Domain Communication And Spread Spectrum Communications, Anti-interference Performance Comparison

Interferences suppression is an important issue on digital communication research.This dissertation compares the interference suppression's performance of transformdomain communication (TDC) and direct sequence spread spectrum communication(DSSC). This dissertation mainly consists of the following three parts:In partⅠ, we introduce the principle and working mechanism of the transformdomain communication and the spread spectrum communication. In partⅡ, we establishthe system model of the transform domain communication and the spread spectrumcommunication. In partⅢ, we investigate the performance of interference suppression ofTDC and DSSC, with regard to different interference scenarios. For widebandinterferences, TDC provides comparable bit error performance to DSSC, as the averagejamming power to-average symbol energy ratios (J/S) ranging from -5dB to 17dB. Fornarrowband interferences, TDC based on ideal spectrum estimation offers average biterror performance approximately 12.84dB above DSSC, as Eb/No equaling to 4dB andJ/S ranging from 0dB to 16 dB. For multi-users interferences, TDC with random codeselection exhibits performance comparable to DSSC with the pseudo-random sequence(PN) code generated from the equably random number generator (RNG) in bothsynchronous and asynchronous multiple access scenarios; however, the bit errorperformance of TDC with orthogonal code selection far exceeds that of DSSC with theGold code for synchronous multiple access, whereas, for asynchronous multiple access,the bit error performance of DSSC with the Gold code is superior to that of TDC withorthogonal code selection. For multi-path fading channel interferences, the bit errorperformance of the TDC approximately equals to that of the DSSC, as Eb/No rangingfrom -5dB to 17dB.