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This study presents some joint source and relay power allocation algorithms in the amplify-and-forward (AF) relay networks using the efficacious geometric programming (GP). According to the constraints, approximate expressions of the received signal-to-noise ratio are first obtained. Thereafter, the problems are cast into appropriate GP forms according to the constraints. The power allocated to the source(s) and to the relays is then determined iteratively via the single condensation method. The new GP approach is shown to be applicable to a variety of constraints by using all of the relays for assistance and is amenable to asymmetric channels in both the single-user and multi-user AF relay networks. Conducted simulations show that the proposed power allocation schemes can attain superior performance compared with the previous works under various constraints in miscellaneous scenarios. [ABSTRACT FROM AUTHOR]

A simple, yet effective, method is proposed to form the group signature sequences for multiple input multiple output (MIMO) multicarrier code-division multiple access (MC-CDMA) systems. By minimising the projection onto a properly constructed subspace, the signature sequences are recursively determined group by group. The simulation results show the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]