Abstract
This paper deals with multiuser detection through
base station cooperation in an uplink, interference-limited, high
frequency reuse scenario. Distributed iterative detection (DID) is
an interference mitigation technique in which the base stations
at different geographical locations exchange detected data iteratively
while performing separate detection and decoding of their
received data streams. This paper explores possible DID receive
strategies and proposes to exchange between base stations only
the processed information for their associated mobile terminals.
The resulting backhaul traffic is considerably lower than that of
existing cooperative multiuser detection strategies. Single-antenna
interference cancellation techniques are employed to generate
local estimates of the dominant interferers at each base station,
which are then combined with their independent received copies
from other base stations, resulting in more effective interference
suppression. Since hard information bits or quantized log-likelihood
ratios (LLRs) are transferred, we investigate the effect
of quantization of the LLR values with the objective of further
reducing the backhaul traffic. Our findings show that schemes
based on nonuniform quantization of the “soft bits” allow for
reducing the backhaul to 1–2 exchanged bits/coded bit.
