Unitary precoding for integer-forcing MIMO linear receivers

A flat fading point-to-point multiple-antenna channel is considered where the channel state information is known at both transmitter and receiver. At the transmitter side, we use a lattice encoder to map information symbols to lattice codewords. The lattice coded layers are then precoded using unitary matrices satisfying non-vanishing minimum product distance. At the receiver side, an integer-forcing linear receiver is employed. This scheme is called `unitary precoded integer-forcing´. We show that by applying the proposed precoding technique full-diversity can be achieved. We then verify this result by conducting computer simulations in a 2 × 2 and 4 × 4 multiple-input multiple-output (MIMO) channel using full-diversity algebraic rotation precoder matrices.