الفهرس | Only 14 pages are availabe for public view |
Abstract OFDM is a promising technique for high rate transmission systems. But, one major drawback or OFEM is the large Peak to Average Power Ratio (PAPR) of the transmitted signal which reduces the efficiency of transmitter power amplifier. The elimination of PAPR can he achieved using Constant Envelope OFDM (CE-OFDM) transformation technique at the expense of BER performance degradation of the system which can be enhanced by adding a Forward Error Correction (FEC). This paper studies the effect of the inclusion of gray QAM mapper on the complexity and the BER performance of CE-OFDM system with channel coding. It has been demonstrated that the inclusion of gray QAM mapper instead of conventional one reduces the receiver complexity of the channel coded CE-OFDM system and greatly improve its BER performance, specially, at low SNR region. A gain of more than 7.5dB is achieved at a BER of l 0-4 over conventional CE-OFDM system when signal transmit1cd over an A WGN channel, while it achieves a gain of more than 8.5dB when signal transmitted over the multipath frequency selective fading channel. |