No abstract

This letter presents two novel power allocation schemes for bidirectional amplify-and-forward (AF) relaying over Rayleigh fading channels through the exploitation of channel mean strength. The first scheme aims to maximize the upper bound of average sum rate, and the other aims to achieve the trade-off of outage probability between two terminals. Numerical results show considerable performance improvement in comparison with conventional power allocation approaches.Index Terms-Amilify-and-forward, average sum-rate, bidirectional relaying, power allocation, outage probability.

Abstract-This work aims to handle the joint transmitter and noncoherent receiver optimization for multiuser single-input multiple-output (MU-SIMO) communications through unsupervised deep learning. It is shown that MU-SIMO can be modeled as a deep neural network with three essential layers, which include a partially-connected linear layer for joint multiuser waveform design at the transmitter side, and two nonlinear layers for the noncoherent signal detection. The proposed approach demonstrates remarkable MU-SIMO noncoherent communication performance in Rayleigh fading channels.Index Terms-Unsupervised deep learning, joint transmitter and receiver design, noncoherent detection, multiuser single-input and multiple-output (MU-SIMO).

Abstract-We consider the channel estimation for the subband orthogonal frequency-division multiple-access (OFDMA) uplink. The channel for each subband is modeled by combing the linear and Fourier basis-expansion functions. Based on this mode, a two-dimensional interpolation approach is proposed for the channel estimation, which is carefully investigated in terms of estimation error and pilot placement.

Abstract-Cooperative communications can exploit the distributed spatial diversity-gain to improve the link performance. In this paper, we investigate the application of adaptive modulation concept to the decode-and-forward (DF) based cooperative network. With the relay nodes geographically close to the destination, we assume the perfect channel feedback is available only at the relay nodes, and propose a class of novel modulation-adaptive cooperation schemes (MACSs). The proposed schemes are first investigated in the single-relay scenario, and then extended to the multi-relay scenario. Simulation results show that the proposed schemes can offer the significant throughput-improvement in comparison with conventional DF systems.