The performances are shown in Fig. 4 for P=1, 2, 3, and 4. We observe that the performance of the SU network can be significantly improved when the CSI consists of multiple delayed channel estimates.
Second, we smooth the initial channel estimates over multiple subblocks of one OFDM block by using polynomial fitting.
In [21], the authors addressed the robust multiple-antenna relay design problem in TWRN and provided the robust multiple-antenna relay design based on the channel estimates.
Second, the temporal channel estimates are further enhanced over multiple OFDMA symbols by using a weighted average procedure.
The problem of jointly optimizing the source precoder, relay transceiver, and destination equalizer has been considered in this paper for a multiple-input-multiple-output (MIMO) amplify-and-forward (AF) relay channel, where the channel estimates of all links are assumed to be imperfect.
The method introduced in [24], for example, finds an ML solution for a joint single-input multiple-output channel and sequence estimation problem using a two-step procedure: (1) channel estimates are obtained for every possible data sequence, and (2) the ML data sequence and corresponding channel estimate are selected.
We design the placement and power distribution to the pilot symbols for multiple transmit antennas to minimize the MSE of the least square (LS) channel estimates.
The impact of the sampling rate, the roll-off factor, the spatial and temporal correlation among channel estimates, the number of channel estimates, and the use of multiple sensors in the antenna at the receiver is studied and related to the mobile subscriber positioning issue.
Essentially the algorithm solves a nonlinear, multiple channel dynamic system.
