ABSTRACT

Data rate is important in telecommunication because it is directly proportional to the cost of transmitting the signal. Saving bits is the same as saving money . In this paper we propose new digital companding scheme for OFDM system based on using different constellation orderings (QAM modulator) , depending on the data to be transmitted . Depending on the data to be transmitted AI (Artificial Intelligent) block compresses and expands the signal, 8 to 3 bit compression is proposed(32:1 compression). The proposed scheme was simulated in Matlab7.4 and it was shown that the proposed companding scheme effective with low compression error.