An Expurgated Union Bound of Punctured Space-Time Turbo Codes

Abstract

This paper presents a new technique to obtain an expurgated union bound on the frame error rate of punctured space-time turbo codes (STTuC) in quasi-static Rayleigh fading channels. The STTuC scheme is composed of two component space-time trellis encoders connected in parallel via an interleaver. An adjacent matrix of an augmented state diagram is defined which allows the enumeration of each punctured component encoder. The distance spectrum of the STTuC is then obtained using the concept of uniform interleaver. A method to identify the dominant error events is proposed and an expurgated union bound on the frame error rate of STTuC schemes is computed using these dominant error events. Comparisons with simulated results reveal that the expurgated union bound is tight for codes with different construction criteria for a wide range of signal to noise ratio.