LDPC Encoder for OFDM Based Cognitive Radio

The objective of this paper is to analyse the working of Low density parity check code scheme (LDPC) for precoded OFDM method. The precoded OFDM overcomes the dearth of availability of spectrum by means of look ahead value insertion at the transmitter so that the interference of the primary channel is eliminated. This aid in transmitting data through the spectrum holes which is the main objective of cognitive radio. The method though prevents the interference from secondary system, the effect of noise which is added by the channel has to be reduced in order to improve the BER.