Optimization of Quantization Levels for Quantize-and-Forward Relaying with QAM Signaling

This paper investigates the uplink coordinated multiple point (CoMP) reception with quantize-and-forward (QF) relaying. In this relaying system, two relay nodes directly quantize the received symbols to integer numbers based on modulo-lattice and parallelly forward these numbers to the destination via optical fiber. In order to reduce the traffic load of optical fiber without sacrificing CoMP gain, we propose an optimization strategy from the viewpoint of mutual information which adaptively controls the quantization level at the relay nodes. We have demonstrated that the proposed optimization is capable of helping the system achieve high throughput and low traffic load of optical fiber at the same time by computer simulations.