On Diversity-Multiplexing Tradeoff of the Interference Channel

In this paper, the tradeoff between diversity and multiplexing gains in the two-user quasi-static Raleigh fading interference channel (IC) is derived. Under the short-term average power constraint and for the delay limited communication, we show that only a partial channel state information at the transmitter (CSIT) is enough to achieve the optimum diversity-multiplexing tradeoff (DMT) at the IC. We develop a coding scheme for the two-user quasi-static Raleigh fading IC. At the low rate region, this results in a one-level Gaussian code independent of the channel condition. At the high rate region, the result can be one-level or two-level Gaussian codes depending on the partial CSIT. The partial state information for each channel gain can be represented by only one bit corresponding to its absolute value. At the high rate region, we assume that the partial state information of all channel gains is available at the two transmit sides. The optimality of the proposed scheme is established by deriving an outer bound, which coincides with the achieved DMT.