On the performance interference cancellation in uplink cooperative wireless networks

The interference cancellation (IC) techniques are studied for cooperative networks with the interference source if the destination and relay are disturbed by the co-channel interference (CCI). In order to solve such interference problem, the beamforming technique with the appropriate weight estimation for array antenna at the destination. We can also control the transmitted power at the interference source, and maintain nearly the diversity gain compare with the existing decode and forward protocol. The system performance can be enhanced by adopting the power control strategy at the interference source by channel quality criterion and signal combining techniques. The maximum ratio combining (MRC) and the cooperative maximum ration combining (C-MRC) are used to combine the received signals arrived at the destination to achieve the minimum probability of error based on the experimental results from simulations. The results show proposed IC C-MRC systems had the lower probability of error than MRC because effect from the weighted of received signal from the relay.

I. Introduction

In classical cooperative communications, the main focus is to improve the capacity performance of single source destination pair through single or multiple relays [1]. Cochannel interference (CCI) originating from the frequency reuse for high spectrum efficiency is a major issue, and by utilizing the concept of relaying in wireless networks, CCI cannot be ignored. In fact, studying the impact of CCI on cooperative networks is not only compulsory. The impact of CCI on the efficiency of cooperative systems was analytically investigated in [2] has been proposed to further improve the capacity performance. Different from the traditional approaches of separating concurrent transmissions, multiple source-destination pairs can now transmit simultaneously by canceling the cross-user interference among them [3]. The authors in [4] proposed co-channel interference (CCI) cancellation strategy based on successive interference cancellation (SIC) employed minimum mean square error (MMSE) and zero-forcing (ZF) algorithm. In [5] consider in the uplink power control problem because of transmitted power is regulated to provide each user an acceptable connection by limiting the interference caused by other users.