On the symmetric feedback capacity of the K-user cyclic interference channel

The K-user cyclic interference channel models a situation in which the kth transmitter causes interference only to the (k - 1)mod(if )th receiver. The impact of noiseless feed-back on the capacity of this channel is studied by focusing on the linear shift deterministic cyclic interference channel (LD-CIC). For the case of symmetric channel parameters, the symmetric feedback capacity is characterized for all interference regimes. It is shown that the symmetric feedback capacity is in general a function of if, the number of users. Furthermore, the capacity gain obtained due to feedback decreases as K increases.