A noncoherent UWB scheme using frequency shifted reference and PPM

Energy detectors (ED) and transmitted reference (TR) systems are known as promising candidates for noncoherent UWB receivers. One way of non-coherent communication, is to use a transmitted reference (TR) pulse for detection. In conventional TR, the reference pulse and data bearing pulse are multiplexed in time domain. In frequency shifted reference (FSR) method, these pulses are multiplexed in the frequency domain, relaxing the need for the delay line at receiver. In this paper we propose a method of using FSR in conjunction with PPM so that two bits can be transmitted in each symbol interval, rather than one. Our simulation result shows that by doing this an approximately 2 dB performance gain can be achieved.