Block Allocation Strategy for Multiple Input Multiple Output (MIMO)–Orthogonal Frequency Division Multiple Access (OFDMA) System

Abstract

The challenge of next generation mobile wireless networks necessitates efficient usage of available spectrum. The multiple input multiple output (MIMO)–orthogonal frequency division multiple access (OFDMA) technology exploits spatial and frequency diversity completely to maximize the usage of the limited available spectrum. The major factor that MIMO–OFDMA system proposes is allocation of interference free blocks for the arriving traffic. The author extends subsequence DPA strategy to MIMO–OFDMA system to transmit real time video traffic. The traffic and channel interference constraints are considered. The system is modeled using generalized stochastic petri nets and the analytical results are validated by simulation. The performance characteristics like mean delay and normalized throughput of subsequence DPA for various combinations are analysed. For 4 × 4 system, subsequence DPA (1, 4) and (2, 2) combinations are analyzed and it is observed that (2, 2) combination performs well than that of (1, 4) combination by 33 and 32% in terms of mean delay and normalized throughput respectively. For 8 × 8 system, subsequence DPA for (1, 8), (2, 4) and (4, 2) combinations are examined and (2, 4) and (4, 2) outperforms (1, 8) by 51 and 75% respectively in terms of mean delay and 48 and 74% respectively for normalized throughput.