Improved Tdd Resource Allocation through Link Gain Estimation

Time division duplex systems, in a convenient way, facilitates the implementation of asymmetrical links required to efficiently handle the increasingly asymmetric traffic offered by current and future wireless applications. If boundaries between uplink and downlink time-slots are not synchronized among cells, e.g. when different asymmetries are required in different cells, inter-base station (IB) interference and inter-mobile (IM) interference arise. To keep the outage probability at a reasonable level this interference need to be avoided. In a system with centralized resource allocation, information about IM link gains can be used to estimate IM interference. Measuring all IM link gains is often considered to be an intractable task. Thus, in this paper a simple method to estimate IM link gains and to avoid IM interference is proposed and evaluated. The method is shown to improve system capacity when applied in a centralized system. The method also preserves fairness properties of the resource allocation algorithm to which it is applied.