Orthogonal Frequency Division Multiple Access (OFDMA) based cellular network can support diverse requirement of multimedia traffic. OFDMA method using adaptive modulation and coding technique can increase the system capacity many fold. In order to meet dynamic bandwidth requirement in downlink, an efficient resource allocation method called Two Stage Rate Adaptive (TSRA) algorithm is proposed here. The TSRA employs an adaptive modulation techniques and a Band Width Adaptation (BWA) algorithm to support the dynamic resource requirement of a multimedia traffic. The BWA is invoked dynamically by TSRA to deal with real-time variable bit rate services. It is observe that the simulated average system capacity exceeds 6 b/s per Hz, and approaches analytical/theoretical limit for increasing no of users. The delay performance is observed for existing and new arrival of multimedia traffic. We also simulate the average BER performance of the TSRA algorithm.

Orthogonal frequency division multiple access (OFDMA) is a promising technique for achieving high capacities in future cellular systems to support multimedia traffic. The OFDMA technique not only allows maximum resource utilisation, but also a very flexible channel management. In order to meet the dynamic bandwidth requirement in downlink, an efficient resource allocation method called two stage rate adaptive (TSRA) algorithm is proposed here. The TSRA meets the quality of service (QoS) requirements of the real time services on the expense of non real time traffic while maximising the dynamic capacity of the OFDMA system. We find that for the higher traffic load, the average capacity of the system approaches the theoretical/analytical limit. The delay and bit error rate (BER) of TSRA observed here can support varieties of multimedia services.

Because of bursty high data rate and delay sensitive nature of high quality multimedia application, the resource allocation in wireless network to meet its quality of service (QoS) has become the most challenging and interesting issue. Orthogonal Frequency Division Multiple Access (OFDMA) employing adaptive channel allocation technique can support these requirement while increasing the system capacity many fold. Here, an efficient resource allocation method called Two Stage Rate Adaptive (TSRA) algorithm is proposed in order to meet dynamic bandwidth requirement in downlink. We model the resource allocation problem with goal of maximizing spectral efficiency. Considering random mix of four categories of multimedia traffic, we find that gap between analytical and simulated average capacity of the system gets smaller as number of user increases and at one point the simulated average system capacity exceeds 6 b/s per Hz. Further, other system parameters like average throughput, delay and BER of the TSRA protocol is presented.

The future cellular wireless network is expected to support a large variety of multimedia traffic in downlink. Orthogonal Frequency Division Multiple Access (OFDMA) technique using adaptive modulation and coding technique can increase the system capacity many fold. In this paper, the performance analysis of an OFDMA system utilizing an efficient resource allocation method, called Two Stage Rate Adaptive (TSRA) algorithm is studied. Considering wide variation in Signal to Interfering Noise Ratio (SINR) dynamically between 3 to 26 dB in Rayleigh channel, and randomly mixing of four categories of multimedia traffic, it is observed that the difference between analytical and simulated average capacity of the system gets smaller as number of user increases, and at one point the simulated average system capacity exceeds 6 b/s per Hz. Apart from spectral efficiency, Bit Error Rate (BER), and delay performance of the proposed system is evaluated here.