Liqaa A. Al-Hashime; Sinan M. Abdul Satar; Ghaida A. AL-Suhail
Volume 18, Issue 3 , December 2018, , Page 33-42
Abstract
Orthogonal Frequency Division Multiplexing is one of the mostimportant multiple carrier modulation format, which has many applications inwireless communication and optical communication. It is considered as anexcellent method for fast optical communication inferable from its high spectralefficiency and ...
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Orthogonal Frequency Division Multiplexing is one of the mostimportant multiple carrier modulation format, which has many applications inwireless communication and optical communication. It is considered as anexcellent method for fast optical communication inferable from its high spectralefficiency and its strength to path losses. Peak to average power ratio isregarded as one of the main problems that are experienced by the opticalorthogonal frequency division multiplexing system, which directly affects thecharacteristics of the system. The current paper proposes an efficient techniqueto reduce Peak to Average Power Ratio by the modified Dursun’s method or theso called modified discrete sliding norm transformer in coherent opticalorthogonal frequency division multiplexing system for the first time to the baseof our knowledge consequently. The proposed technique does not need to sendside information to the receiver; also, it does not degrade bandwidth. Thisalgorithm lessens Peak to Average Power Ratio in the optical coherentOrthogonal Frequency Division Multiplexing system to about 4.15 dB atcomplementary cumulative distribution function (CCDF) probability of 10-3 andimproves the system performance.
Ali n. Kareem; Sinan M. Abdul Satar; Mohammed A. Husein
Volume 18, Issue 3 , December 2018, , Page 60-69
Abstract
orthogonal frequency division multiplexing (OFDM) is emerging asthe leading technology for high data rates. The OFDM based on multicarriertransmission that transforms a wideband channel into a group of thin-bandchannels. The high peak to average power ratio (PAPR) considers the maindrawback factor in ...
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orthogonal frequency division multiplexing (OFDM) is emerging asthe leading technology for high data rates. The OFDM based on multicarriertransmission that transforms a wideband channel into a group of thin-bandchannels. The high peak to average power ratio (PAPR) considers the maindrawback factor in this system, so the companding technique modifies theamplitude of OFDM signal to reduce this factor. The proposed A-lawcompanding technique has been implemented in intensity modulation/directdetection optical orthogonal frequency division multiplexing (IM/DDOOFDM).The proposed companding scheme guarantees the improvedperformance in terms of bit error rate (BER) and quality factor (QF) whilereducing PAPR effectively and efficiently by modifying the amplitude of thetransmitted signals. Our results confirm that the suggested scheme exhibits agood ability to reduce PAPR and a good BER performance based on the use theA factor. At the complementary cumulative distribution function (CCDF) of 10-3, the PAPR value of our proposed scheme is about 4.4 dB lower than those ofun-companded signal at best control factor used of A at 87.6, accordingly theQF is 2.5 dB and the BER is 6.2×10-3 at a distance 900km without anyequalization technique or training sequence or any channel estimation.