A Non-Cooperative Method for Path Loss Estimation in Femtocell Networks

TL;DR

This paper introduces a non-cooperative method for femtocell users to independently estimate path loss to macrocell users, improving interference management in two-tier networks.

Contribution

It proposes a novel non-cooperative approach combining MAP and MMSE methods for accurate path loss estimation without information exchange.

Findings

Efficient path loss estimation in various conditions

Improved interference management in femtocell networks

High estimation accuracy demonstrated through simulations

Abstract

A macrocell superposed by indoor deployed femtocells forms a geography-overlapped and spectrum-shared two tier network, which can efficiently improve coverage and enhance system capacity. It is important for reducing inter-tier co-channel interference that any femtocell user (FU) can select suitable access channel according to the path losses between itself and the macrocell users (MUs). Path loss should be estimated non-cooperatively since information exchange is difficult between macrocell and femtocells. In this paper, a novel method is proposed for FU to estimate the path loss between itself and any MU independently. According to the adaptive modulation and coding (AMC) mode information broadcasted by the macrocell base station (BS), FU first estimates the path loss between BS and a MU by using Maximum a Posteriori (MAP) method. The probability distribution function (PDF) and statistics of the transmission power of the MU is then derived. According to the sequence of received powers from the MU, FU estimates the path loss between itself and the MU by using minimum mean square error (MMSE) method. Simulation results show that the proposed method can efficiently estimate the path loss between any FU and any MU in all kinds of conditions.