Swarm intelligence based dynamic subcarrier bit and power allocation for ofdma relay networks

Abstract

Orthogonal Frequency Division Multiplexing OFDM is a newlinepromising and a reliable solution for future wireless communication networks newlineOFDM provides a high performance physical layer and medium access newlinecontrol due to its capability to combat Inter Symbol Interference ISI and newlinemultipath fading Moreover multiuser diversity can be exploited by OFDM newlinewhich is inherent in the multiuser wireless network via dynamic subcarrier newlineallocation newlineThe toughest concern in OFDM system is the problem of subcarrier newlineand power allocation in a multiuser network to reduce the transmitted power newlineand maximize the total data rate or a utility function of data rate of users newlineResource allocation in OFDM has become one of the active areas newlineof research which refers to assigning subcarrier to consumer and choosing the newlinepower level and the modulation approach on the assigned subcarrier with the newlinegoal of satisfying individual consumer Quality of Service QS necessities newlineIn an Orthogonal Frequency Division Multiple Access OFDMA newlinerelay network with a single source a single relay and a single destination the newlineinstantaneous rate of the source is increased by power allocation approach newlineIn an OFDMA relay network with a single source multiple relays newlineand multiple destinations the sum rate of the relay network is increased by newlineheuristic subchannel allocation approach newlineIn an OFDMA relay network with multiple sources multiple newlinerelays and a single destination the sum rate per subcarrier is increased by newlinesubcarrier allocation approach newlineThe opening in relaying and OFDMA approach also provide certain newlineexciting challenges due to the increased dynamics degree of freedom and newlineresource reuse and difficulties present in resource allocation and interference newlinemanagement This reality emphasizes the significance and necessity of newlinedynamic and intelligent resource allocation approach with efficient spectrum newlineutilization The fundamental resources in OFDM are Subchannel and Power newlineSubchannels experience frequency selective fading which takes different newlinevalues for different users newline newline