Capacity analysis of adaptive multiuser frequency-time domain radio resource allocation in OFDMA systems

In this paper, we present the adaptive multiuser frequency-time domain radio resource allocation model which adaptively allocates the radio resource jointly in the frequency and time domain to exploit the frequency diversity and time diversity as well as multiuser diversity. Then we give an in-depth capacity analysis of the proposed radio resource allocation with frequency-time domain power adaptation in the downlink OFDMA systems and draw a comparison with the conventional frequency domain resource allocation method. Simulation results show that: 1) the proposed resource allocation method achieves much higher spectral efficiency than the conventional frequency-domain resource allocation; and 2) for the proposed two-dimensional allocation method, the performance of water-filling power allocation is almost the same as that of the equal power allocation, especially when the number of user is large