The authors consider K-user cyclic single-inputa??single-output (SISO) interference channel (IC) where each receiver is interfered with from only one neighbouring transmitter. In the K-user cyclic SISO IC, K/2 sum degrees of freedom can be achieved when two-symbol extension is applied even without channel state information at the transmitter. They derive an approximation of the ergodic sum rate as a function of pre-coders and propose designs of pre-coders to maximise the ergodic sum rate.
展开▼