Abstract: In wireless communication, the interleavers are referred as the core component for many multiple access schemes e.g., IDMA, CDMA etc. In CDMA systems, interleavers are mainly employed for providing the coding gain to signal while in IDMA systems, user-specific interleavers are used for the purpose of user separation. For implementation of the interleavers in IDMA, the challenge is to fabricate them at affordable decoding complexity with available technology. In this study, we first introduce various orthogonal and non-orthogonal interleavers user in IDMA scheme. Then, we perform comparison on their performance and implementation complexity. Here we are dealing with suitable interleavers only which are used as the only means of user separation in IDMA scheme. Tree based interleaver turned out to be the best compromise between performance and complexity. Next, we implement interleavers on VHDL as the design and simulation entry.