A new M-ary wideband communication system with application to multipath channels .II. Experimental results

For pt. I see ibid., vol.43, no.1, p.127, 1995. We present a new M-ary wideband communication system based on use of binary spread-spectrum sequences and a correlation receiver. The proposed system offers a significant savings in receiver complexity compared to classical M-ary systems as one correlator is required and also the word synchronization can be automatically made. The sequences used here were primarily described by Yates and Holgate (1979) and generalized by Potter (1980). A set of Yates-Holgate (Y-H) sequences is constructed from a single m-sequence called the “parent”. When any sequence in the set is cross-correlated with the “parent”, the cross-correlation function (CCF) obtained has a shape that simply and uniquely identifies that sequence; at the same time, it defines the word synchronization. The transmitter associates k information bits to a sequence of N chips selected in a Y-H set of M=2^k sequences. The receiver correlates the received sequence with the parent and hence can decide what sequence has been transmitted. In this way, the receiver can recover the k information bits. We give results from a communication experiment that we conducted with this system and have compared it with a classical M-ary communication system using a set of Gold sequences with same parameters (energy, duration, bandwidth). The obtained performance shows that the system is quite robust