Distributed Interference Alignment for Multi-Antenna Cellular Networks With Dynamic Time Division Duplex.

In this letter, we propose a distributed interference alignment (DIA) technique in a two-cell multiple-input multiple-output (MIMO) network with dynamic time division duplex (TDD) mode under local channel state information assumption. The dynamic TDD operation introduces new types of interference, such as downlink-to-uplink [base station to base station (BS-BS)] and uplink-to-downlink [mobile station to mobile station (MS-MS)] interferences. Under the assumption of rank-deficient BS-BS MIMO interference channel, we mathematically characterize the achievable degrees-of-freedom of the proposed DIA technique for a given number of antennas at BS/MS. Through extensive computer simulations, it is shown that the proposed DIA technique outperforms the conventional techniques in terms of sum-rate at the cost of signaling overheads for the BS-BS and MS-MS channel overhearing.