An Efficient Relay Selection Method Based on ANN Channel Estimation Technique for Amplify and Forward Relay in Cooperative Networks

Abstract

Owing to high degree of flexibility, Artificial Neural Networks (ANN) can be used to model nonlinear channel estimation phenomenon. An ANN-based channel estimation technique and relay selection scheme was proposed as an alternate to Fuzzy Logic Controller (FLC) based channel estimation system. ANN's learning property is fully exploited to decipher the deteriorated symbols through extreme faded networks. Similar to FLC channel estimation techniques, this technique is found to be more effective in increasing bandwidth. Simulated results for Multi-input Multi-output (MIMO) of 2×2 and 4×4 using Additive White Gaussian Noise (AWGN) and Rayleigh channel in terms of quantity (Mbps) compared with Signal to Noise Ratio (SNR) over a choice of 0 to 30 dB. This illustrates the effectiveness of the knowledge proficiency of ANNs is 92.19% of AWGN and 94.62% of Rayleigh whereas for FLC is 70.34% of AWGN and 75.51% of Rayleigh channel.

Estimating Time and Frequency under Imperfect Channel Knowledge using ECM and SAGE Algorithms in Multi-relay Cooperative Networks

“…Maximum Likelihood (ML) method does not need any channel information as required in MMSE and LS method. ML is performed through log-likelihood function [12], [8]. The log-likelihood function for θ and ε, i.e., ˄ (θ, ε) is the logarithm of the probability density function f (r| θ, ε) for the 2N+L observed samples in r given the arrival time θ and the carrier frequency offset ε, i.e., ˄(𝜃, 𝜀) = log 𝑓 (𝒓|𝜃, 𝜀) (15) where θ and ε are the time and carrier frequency offsets respectively.…”

“…As per the system model it is double hop, meaning that there is not any inter-relay contact and the source identifies all the relays channel information using the feedback loop. It is considered that the source transmission power is 𝐸 𝑠 and 𝐸 𝑟𝑖 is the ith relay's transmission power [6,12,21]. At this instant let 'Xi' be the information transmitted by the source and 'Yo' be the received signal at the destination and denoted as:…”