Equivalence between SLNR and MMSE precoding schemes in the K-user MISO interference channel

We consider a transmit precoder design for the K-user multiple-input single-output (MISO) interference channel in which each transmitter is equipped with multiple transmit antennas and each receiver employs a single receive antenna. First, we derive a closed-form expression for a minimum mean-square error (MMSE) precoder and an alternative expression for a signal-to-leakage plus noise ratio (SLNR) precoder. Then, the equivalence between the two precoders is proved. Through simulation results, we demonstrate that the sum capacity and bit error rate (BER) performance of the SLNR precoder are the same as the MMSE precoder and that they are better than that of the zero-forcing (ZF) precoder. Key-Words: Interference channel, multiple-input single-output, precoding, minimum mean squared error (MMSE), signal-to-leakage-plus noise ratio (SLNR).