antenna is selected which maximizes the received signal-to-noise ratio (SNR) for broadcasting the information through the channel vector PP to the receiver and is given as (6.1) where P E {S,R}, Q E {R, D}, and P # Q. Channel matrix HpQ has the Np channel vectors (CP) with dimensions NQ X 1 of each. Minimum mean square error (MMSE)-based estimator is used at the receiver for channel estimation. To visualize the versatility of the channel in the system performance, all are assumed to be modeled by the generalize complex Nakagami-m frequency flat fading channels, Nak(ML, 22). All the noise vectors are assumed to be modeled by additive white Gaussian noise (AWGN) vectors with mean 0 and variance OPOING. CEEs in channel estimation arises due to the improper pilot pattern. Improper pilot pattern results in irreducible error floor in channel estimation. To avoid CEEs, pilot pattern should be performed as a function of coherence time and frequency [27]. The relation between the actual channel (H) and the estimated channel (H) in the presence of CEE (8H) is given as H=Â+8H, (6.2) where is modeled as CN(0, o?1) and the variance of is given as (6.3) p=02/02.0<p<1 (6.4) P. Shaik and V. Bhatia where p is the channel correlation coefficient [28]. Variance of the estimated channel is given as o2 = 02 - 02 = = po2. For harvesting the energy, we consider TS protocol at the R. The system operation completes in two phases. Energy is harvested at R in the first phase, from the received S signals, whereas IP takes place in the second phase. 6.3.1.1 Time Switching Protocol As discussed, we employ TS protocol to harvest the energy at the R due to its reduced complexity. Entire communication between S and D takes place over a period of (T) time in two phases as shown in Fig. 6.1. The complete time T is divided into aT time and (1 - a)T for energy harvesting and IP. a denotes the fraction of time, 0 <a< 1. 6.3.1.2 Phase 1 In this phase, energy is harvested at R for aT time. 6.3.1.3 Phase 2 In the second phase, communication link is esta