Two-Stage and Walsh Interleavers for Interleave Division Multiple Access Systems

Abstract

Interleavers are essential system components for interleave division multiple access (IDMA). In this paper, two-stage interleavers are proposed based on two optimization criteria combines minimum spreading distance with regular permutation and randomization properties to have almost the same advantages of the random distribution, and yet guaranties an enlarged minimum spread distance. Simulationresults show sufficiently good performance with much less resource consumption compared to multiple random interleavers. The proposed method may also find other application areas such as multi-dimensional concatenated codes. In addition, an efficient and simple procedure is proposed to generate orthogonal interleavers by using the well-known Walsh-Hadamard transform.