Performance evaluation of adaptive internally turbo coded ultra wideband-impulse radio (AITC-UWB-IR) in multipath channels

A UWB-IR system transmits a number of consecutive pulses for an information symbol. Thus, the UWB-IR system is considered as a coded scheme with a simple repetition block code. We proposed an adaptive internally turbo coded UWB-IR (AITC-UWB-IR) system where the turbo code and repetition block code are used adaptively (Yamamoto, N. and Ohtsuki, I., Proc. ICC 2003). We showed that the performance of the AITC-UWB-IR system is superior to that of the conventional UWB-IR system using the simple repetition block code in an AWGN channel and a real Gaussian fading channel. We evaluate the performance of the AITC-UWB-IR system using a RAKE receiver in the UWB channels. As a RAKE receiver, we use the selective-RAKE (SRAKE) receiver. From the results of our computer simulations, we show that the AITC-UWB-IR system achieves a good error rate performance, because the code rate of the turbo code and the number of pulse repetitions are set adaptively.