Resource Allocation in OFDM Based Wireless Relay Networks ...

3.7 Summary
3
2.8
2.6
JntOpt
SubOpt
SolWOP
Static
bits/s/Hz
2.4
2.2
2
1.8
1.6
2 4 6 8 10 12 14 16 18 20
M
Figure 3.5: Throughput versus the number of users at SNR= 10 dB.
number of users.
To get a more insight into the performance gain achieved from tone matching,
in the next example we compare JntOpt and SubOpt with SolWOP under the case
when |h m,1 | > |h m,2 | . . . > |h m,K |, |˜h m,1 | < |˜h m,2 | . . . < |˜h m,K |, |g m,1 | > |g m,2 | . . . >
|g m,K |, |˜g m,1 | < |˜g m,2 | . . . < |˜g m,K |, ∀m. The throughput curves versus SNR for
M = 2 and M = 10 are shown in Fig. 3.6. It can be seen that JntOpt and SubOpt
yield good performance. However, SolWOP exhibits much worse performance as
compared to that in Fig. 3.4 because the good channel in MAP is always paired
with the bad channel in BCP when no pairing strategy is adopted.
3.7 Summary
In this chapter, we developed power and sub-carrier allocation algorithms for
multi-user bidirectional relay networks. The objective was to maximize the total
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