The Extended Application Of Subcarrier And Power Allocation In WFRFT Spread OFDM

With the development of wireless communication and the growth of thewireless communication device and wireless communication subscriber, theresources of wireless communication becoming saturate, how to improve utilizationof the radio resources gradually becomes a hot research topic. In order to satisfy theincreasing requirements of the wireless communication system performance, highorder modulation, resource allocation and modulation mode gradually areintroduced into the subject of current research to increase the spectral efficiency.The main contents of this paper is under the theory of the weighted fractionalFourier transform (Weighted-type Fractional Fourier Transform, WFRFT),comparing to orthogonal frequency division multiplexing (Orthogonal Frequency-Division Multiplexing, OFDM) system and discrete Fourier transform spreadorthogonal frequency division multiplexing (DFT-S-OFDM) system to allocateresources by the optimization method to study a new hybrid carrier modulationsystem that is weighted fractional Fourier transform spread orthogonal frequencydivision multiplexing (WFRFT resource allocation problem-S-OFDM) systems.In the wireless communication system, the resource allocation can be dividedinto two aspects: First, the sub-carrier allocation; the other power allocation.Therefore the current study of resource allocation is concentrated on the sub-carrierallocation and power allocation. And a number of strategies have been proposedabout the OFDM sub-carrier allocation and the power allocation. In the actualsingle-user system, if using subcarrier allocation, since discarding some subcarriers,it will certainly cause a decline in the frequency band utilization, while in the actualmulti-user system, if using subcarrier allocation, it will definitely lead a decline infairness of multiple users; In the actual communication system, if using powerallocation, it will definitely lead a decline in fairness of different subcarriers.Therefore the process of subcarrier allocation and power allocation is thecompromise between pluralities of system performance.In this paper, the channel selected as multipath Rayleigh fading channel andGaussian white noise channel, subcarrier allocation and power distribution ofOFDM and DFT-S-OFDM system are studied in detail. In this paper subcarrierallocation and power allocation of WFRFT-S-OFDM are derived, and the differences between WFRFT-S-OFDM, OFDM, and DFT-S-OFDM are researched.In addition, this paper also establishes a communication system power allocati onsystem model, and in order to solve the power allocation of WFRFT-S-OFDMsystem, this paper introduces particle swarm optimization algorithm to WFRFT-S-OFDM system to approximate the system optimization of power allocation. Andthree kinds of power allocation in WFRFT-S-OFDM systems is compared in thispaper: one specific linear weighted power allocation; Second PSO search powerdistribution; Third the improved PSO power allocation.