Lakshmi Pujitha Dachuri and Nalini Uppala
Energy Efficient Transmission of Image over DWTOFDM System
1264 - 1270
2013
7
9
International Journal of Electrical and Computer Engineering
https://publications.waset.org/pdf/17353
https://publications.waset.org/vol/81
World Academy of Science, Engineering and Technology
In many applications retransmissions of lost packets are not permitted. OFDM is a multicarrier modulation scheme having excellent performance which allows overlapping in frequency domain. With OFDM there is a simple way of dealing with multipath relatively simple DSP algorithms.
In this paper, an image frame is compressed using DWT, and the compressed data is arranged in data vectors, each with equal number of coefficients. These vectors are quantized and binary coded to get the bit steams, which are then packetized and intelligently mapped to the OFDM system. Based on onebit channel state information at the transmitter, the descriptions in order of descending priority are assigned to the currently good channels such that poorer subchannels can only affect the lesser important data vectors. We consider only onebit channel state information available at the transmitter, informing only about the subchannels to be good or bad. For a good subchannel, instantaneous received power should be greater than a threshold Pth. Otherwise, the subchannel is in fading state and considered bad for that batch of coefficients. In order to reduce the system power consumption, the mapped descriptions onto the bad sub channels are dropped at the transmitter. The binary channel state information gives an opportunity to map the bit streams intelligently and to save a reasonable amount of power. By using MAT LAB simulation we can analysis the performance of our proposed scheme, in terms of system energy saving without compromising the received quality in terms of peak signalnoise ratio.
Open Science Index 81, 2013