Abstrait

Subcarrier Resource Allocation Based Cooperative OFDMA Systems with QPSK Modulation

Ansu Elizabeth Baby, Blessy J, Dr. Sreeja Mole S S

This project proposes the cooperative multiuser OFDMA systems with subcarrier resource allocation technique. A particular subcarrier resource allocation approach about which this paper proposes is a method, based on nodes that transmit and receive on adjacent OFDM subcarriers simultaneously. I propose a transceiver structure to reduce the interference between transmitting subcarriers and receiving subcarriers. The transceiver structure includes QPSK (Quadrature Phase Shift Keying).In this two sets of signals would be mixed; the required 90o of phase separation between the carriers allows the sidebands to be separated by the receiver using phase discrimination. Its performance in terms of signal to interference and noise ratio (SINR) is evaluated by simulation and is incorporated into a recently proposed cooperation strategy for OFDMA systems to examine its performance under the realistic structure.It is shown that SINR increased when QPSK modulation used.