An Effective Subcarrier Allocation Algorithm for Future Wireless Communication Systems

This paper focuses on the algorithm for effective allocation of radio resources in future wireless communication systems. Conventionally the radio resources that have been used to add capacity to wireless communication systems are radio bandwidth and transmitter power. These two resources are simply not growing or improving at rates that can support expected demands for wireless capacity. Keeping in mind, the scarcity of spectrum resources, the challenge of providing better Qos (BER & Bit Rate) through supporting increased mobility and throughput of multimedia services can only be dealt with when elements of radio network are properly configured and suitable radio resource management algorithms applied along with efficient modulation and multiple access modes. The purpose of resource allocation is to intelligently allocate limited resources; it has been proved that the system spectral efficiency can be significantly enhanced by adjusting the allocation of carriers, power and constellation sizes in accordance with the user’s channel conditions and traffic requirements. This paper is concerned with adaptive subcarrier allocation to users with their rate requirements put into consideration. Given that the complexity reduction is of big concern for practical implementation and that fixed power allocation leads to a negligible throughput penalty if the power is poured only in the sub channels with good channel gains, only subcarriers are adaptively allocated to users placed randomly in a cell and the constellation size is according to user’s channel condition.