Union Bound Analysis of Bit Interleaved Coded Orthogonal Modulation with Differential Precoding

A union bound on the performance of bit interleaved coded orthogonal modulation (BICOM) is presented. The bound is derived by representing the system as an equivalent serially concatenated convolutional code (SCCC). Differential precoding prior to orthogonal modulation is shown to provide an interleaver gain, and termination of the differential precoder with a tail bit is taken into account in the bound. The bounds are evaluated for both coherent and noncoherent detection in AWGN and fully interleaved Rayleigh fading and shown to be tight by comparison against simulation results