On channel estimation and detection for amplify‐and‐forward orthogonal frequency division multiplexing‐based two‐way relay systems under unknown non‐reciprocal doubly selective fading channels

Data‐assisted channel estimation and performance analysis for two‐way amplify‐and‐forward relay networks with M ‐ary frequency shift keying modulation

“…Furthermore, C yy is the 2P × 2P Hermitian auto-covariance matrix of (13) and (14) III. Updateb by (12) IV. Repeat steps II and III till an accuracy measure is met y(2k) whose entry on the ith row and jth column is given by…”

“…In an effective approach to solve this problem, Wang et al [10] employed complex-exponential basis expansion model (CE-BEM) for time-selective channels and extracted BEM coefficients from transmitted pilots in order to reconstruct the channel coefficients. Following that, a number of researchers further investigated this subject [11,12]. Several other references have employed orthogonal signalling, such as frequency shift keying (FSK), to circumvent the need for pilot or training symbols in time-varying environments [13].…”

Opportunistic source‐pair selection method with imperfect channel state information for multiuser bi‐directional relaying networks

“…The literature also contains an alternative method, which is an orthogonal transmission technique, to deal with ICI and also investigates the channel estimation techniques/imperfect CSI effects on the TWR systems [24]. Unnikrishnan and Rajan [25] considered the same system structure as in [7] and employed a single/multiple antennas at the user‐pair/relay terminals based on the system model structure.…”

Approximate Gibbs algorithm for blind data detection in two‐way relay networks

“…In [10], the authors investigated respective channel estimation for AF‐based TWRN. The authors of [11] investigated channel estimation and data detection under unknown non‐reciprocal doubly selective fading channels. [12] proposed a method for channel estimation and symbol detection in TWRN with frequency shift keying signalling.…”