TCH (Tomlinson, Cercas, Hughes) codes are very low rate codes with good overall performance. Moreover, TCH sequences have good auto-correlation characteristics, making them suitable for spread spectrum systems. In this paper we consider the use of TCH codes in standard UWB systems (time-hopping and direct sequence employing pulse-position and pulse-amplitude modulations) where performance results are comparable to other pseudo-random codes. A performance advantage is gained when TCH codes are used for combined coding and spreading in Ul-trawide Band Systems.
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