Channel Estimation for Full-Duplex Relay Systems With Large-Scale Antenna Arrays

Physical-Layer Security for Untrusted UAV-Assisted Full-Duplex Wireless Networks

“…We assume that D has full knowledge of x j , and full channel state information (CSI), i.e., for each i ∈ U, the CSI of the link between S and i, and the CSI of the link between i and D. This enables jamming signal cancellation and MRC based detection. We assume that the UAVs do not hinder the CSI acquisition process [19].…”

Optimal Training for Residual Self-Interference for Full-Duplex One-Way Relays

“…The two channels between nodes are assumed to be flat fading modeled by independent complex Gaussian random variable with zero means and variances σ 2 sr , σ 2 rd , respectively. A separate pre-stage is assumed to gather the information of the self-interference channel to perform analog and digital cancellation methods in the next transmission stage [3], [26]. During the transmission, the self-interference is reduced in RF with analog cancellation methods until the residual self-interference power falls in the ADC dynamic range, and then is further suppressed by digital methods.…”

“…Since the line of sight (LoS) component of the self-interference varies very slowly, it can be much reduced by the RF cancellation, which means the reflected multi-path component dominates the RSI in the transmission stage [25], [26]. Under the assumption that the LoS component is reduced and the bulk of the interference is from scattering components, the RSI channel h rr can be modeled as a complex Gaussian random variable with zero mean and variance σ 2 rr [25].…”

“…In the MIMO case, the signal distortion caused by hardware impediments like the limited dynamic-range of non-ideal amplifiers, oscillators, ADCs, and DACs has to be considered [20]- [24] when modeling the RSI channel. However, with sufficient passive self-interference suppression and analog cancellation in RF [3], the distortion can be ignored [8], which leads to a Gaussian model for the RSI channel [16], [25], [26]. The Gaussian model still works when the distortion has to be considered.…”

“…From the RSI channel estimation point of view, reference [26] proposes two methods for the RSI channel in an AF relay system where the destination is equipped with massive MIMO. In the first method the authors consider the case where the RSI channel is estimated by the relay itself, and in the second method the base station estimates the RSI channel.…”