Performance Evaluation of IDMA-Based Random Access Considering User Detection and Channel Estimation

This paper evaluates the performance of interleave division multiple access (IDMA)-based random access in order to support massive machine-type communications (mMTC) in the fifth generation mobile communication system taking into account actual user detection and channel estimation using a preamble attached to the packet. To suppress the packet loss due to contention and achieve multi-packet reception, accurate user detection and channel estimation, which are used in the successive interference canceller (SIC)process in IDMA, are essential. Multiple preamble sequences, each of which has a one-to-one relationship with the interleaver pattern prepared in the system, are generated by applying a cyclic time shift and orthogonal masking operations to Zadoff-Chu (ZC) sequences. Based on the threshold decision on the correlation between the received signal and each preamble sequence, user detection and channel estimation are performed. Computer simulation results show the impact of the preamble overhead, miss detection and false alarm in the user detection, channel estimation error, and the case when multiple users simultaneously select the same interleaver on the achievable performance of IDMA-based random access.