Impact of channel estimation error on upper bound of rate loss for macro cell in a VFDM system

Vandermonde-subspace frequency division multiplexing (VFDM) is a newly-proposed spectrum sharing technology, where perfect channel state information (CSI) is required. In this paper, considering complex Gaussian distributed channel estimation error, we study the interference leakage from small cell (SC) to macro cell (MC) due to imperfect CSI. The probability density function (PDF) of the upper bound of interference leakage is carefully derived. With that PDF, the distribution of the rate loss upper bound is further achieved. Simulation results are presented to validate the correctness of the theoretical derivation and to discover the impact of imperfect CSI on the performance degradation of the MC.