In such a case, and for the considered channel model, numerical results have shown that [13] FMT with adaptive OH does not significantly improve the achievable rate, and in general the minimal length pulse that achieves the highest achievable rate is the one with N = (9/8)M.
Eventually, to compute the OAF achievable rate when the system is subject to a PSD constraint, we can simply compute the DT and the AF achievable rates obtained setting the powers to P ¯, and then we can choose the mode that gives the highest achievable rate (24).
We observe that joint power and bandwidth optimization always yields higher achievable rates than power optimization alone, establishing the merit of bandwidth sharing.
Our analysis has shown that cooperative relaying is generally beneficial in the low-power regime, resulting in higher achievable rates when compared to direct transmission.
Lower rates are also seen in the area around the border of each cell, whereas somewhat higher achievable rates (orange to yellow to white) are seen near areas that correspond to the directions of the macro BS boresights.
For instance, in a cellular CDMA system, dynamic power adjustment is used to equalize the received power of users at the base-station (relay) resulting in a higher achievable rates in the system[12].
From the system design point of view, we conclude that, for this two-hop, simple network, higher achievable rates can be obtained by optimally allocating resources between multiple standards.
By rotating the clustering pattern by 60° around any macro site (see Fig. 1b), those previously poor-coverage users are now in the middle of the cluster (i.e., they will have better channel gains or higher achievable rates).
Fig. 6 Observation on the different usage of the interleaver Q. Shuffling the coded alphabets ({x_{1}^{N}}) as randomly as possible exhibits higher achievable rates compared to the ordered interleaver.
Given the channel conditions between nodes, we study how to allocate resources to achieve the higher achievable rate.
