Novel UWB and Spread Spectrum System Using Time Compression and Overlap-Add Techniques

Abstract

We present a UWB and spread spectrum communications method based on the idea of time compression where a sampled message signal is transmitted at a higher sampling rate. Robustness is achieved by dividing the signal into overlapping segments, transmitting each segment fast enough so that the segments no longer overlap, receiving these segments and reconstructing the message by overlap-adding the segments. A key feature of this scheme is that an exact sample rate match is not required to recover the signal. This method is implemented in a custom wideband software defined radio, with good results in the presence of interference and multipath. This method, referred to as time compression overlap-add (TC-OLA), represents a new concept and design approach and an advance in fundamental technology of the air interface physical layer that may be relevant to 5G wireless technologies.