Simultaneous wireless information and power transfer (SWIPT) provides an efficient approach towards prolonging the lifespan of wireless systems in 5G and beyond 5G communications by minimizing the reliance of devices on batteries and power sources. This paper suggests a SWIPT-assisted cooperative nonorthogonal multiple access (C-NOMA) network where a SWIPT enabled energy harvesting (EH) relay harvests energy from the source and utilizes it to forward the information to the end-user devices in the downlink. In order to obtain a realistic analysis, we aim to utilize a non-linear energy harvesting model and imperfect successive interference cancellation (imp-SIC) at the end user. The closed form expressions of outage probability (OP) and throughput are derived by considering multiple interfering signals at relay. Subsequently, the impact of the number of interferers on harvested energy and the OP, the power splitting (p.s.) ratio, distance between the nodes, and power allocation (p.a) factors are discussed in detail, and a comparison is presented against the traditional orthogonal multiple access (OMA) under the same conditions. The analysis clearly depicts that the proposed SWIPT-based C-NOMA system outperforms OMA in all aspects. Monte Carlo simulations are performed to corroborate the accuracy of the proposed analytical framework.

This paper presents the mathematical model for symbol error probability of triangular quadrature amplitude modulation in a single-input multi-output environment. The symbol error probability performance is evaluated over fading channels namely Rayleigh, Nakagami-m, Nakagami-n, and Nakagami-q. The maximal-ratio combining technique is considered as spatial diversity algorithm and unified moment-generating-function-based approach is applied to derive the results. The multiple channels considered are independent but not necessarily identically distributed. The results presented are valid for slow and frequency non-selective fading channels only. The symbol error probability expressions obtained contain single integrals with finite limits and integrand composed of elementary functions which help us evaluate our analytical expressions numerically. We also compare these expressions with the error performances obtained through computer simulation, which show excellent agreement. In addition, an example has been simulated to validate our derived mathematical expressions.

Continuous Phase Modulation–Direct Sequence Spread Spectrum (CPM-DSSS) is a promising scheme for a secured Point-to-Point (P2P) communication system having Anti-Jamming (AJ) capabilities. However, like other communication systems, synchronization of CPM-DSSS based systems is required for reliable detection of data. This paper presents a novel algorithm for estimating the timing and phase offset for binary full-response CPM-DSSS based systems. A burst mode transmission is considered here, and within each burst, a training sequence is embedded along with data. Firstly, the entire burst is spread using DSSS and then modulated with CPM, which is later upconverted and passed on to the channel. After down-conversion at the receiver, the proposed algorithm estimates timing and phase offset from the received spread training sequence. Then estimation accuracy of the proposed algorithm is compared with the state-of-the-art. The results indicate that the proposed joint estimator is superior by 9 dB and 10 dB for the estimation of timing and phase offset, respectively, as compared to the existing algorithm. Furthermore, the estimator’s variance for three different frequency pulses is compared with Modified Cramer-Rao Bound (MCRB). The results suggest that the phase offset estimator’s variance approaches MCRB for all Signal-to-Noise Ratios (SNRs). The effectiveness of the proposed algorithm in the multipath fading channel is also demonstrated.

In antenna design, it is important to optimize the amplitude weights of a linear antenna array to achieve low peak sidelobe level (PSLL). This paper deals with a linear inequality constraint on array factor to get maximum response in look direction and reduced sidelobe levels in a specified stop band region. Linear regular array as well as thinned linear array is optimized using a constrained genetic algorithm (CGA). The convergence of the optimization algorithm is also reported and its utility is shown in getting a desired antenna beam pattern with fewer radiating elements. Thinning is achieved by iteratively applying CGA which results in reducing the number of elements by 28% and overall transmitted energy by 27%, keeping a specified beam width first null (BWFN) with considerable reduction in PSLL.