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This paper introduces a novel code called two dimensional Pascal’s triangle zero cross correlation (2D-PTZCC) for spectral/spatial coding with its structure of the corresponding system to implement in spectral amplitude coding optical code division multiple access (SAC-OCDMA) systems The novel code is derived from a one dimensional zero cross correlation (1D-ZCC) code using Pascal’s triangle rule. The analytical results prove that the proposed code has totally removed the multiple access interference (MAI), in addition the phase induced intensity noise (PIIN) influence is highly reduced due to the zero cross correlation (ZCC) property. Comparing with the recent developed two-dimensional codes like 2D multi diagonal (2D-MD), 2D dynamic cyclic shift (2D-DCS), 2D diluted perfect difference (2D-DPD) and 2D perfect difference (2D-PD) codes for the same code length. The results of simulation show that the suggested code improve the system capacity and increase the number of simultaneous users reaches 29 % and 64 % comparing to 2D-DPD and 2D-PD codes, respectively. As well, it supplies higher signal power and data bit rates whereas it saves effective source power around −0.81dBm for 2D-DCS and 2D-DPD codes and consumes minor light spectral width. The passage from 1D to 2D ameliorated 1.68 times the system capacity and saved around $ - 4.27{\rm{ dBm}}$ the effective power for each user.

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In OFDM systems, peak-to-average power ratio (PAPR) reduction of the signal is one of the main challenges that need to be overcome in order to use the transmitter in an efficient manner. As one of attractive techniques, interleaving can be used in PAPR reduction for multicarrier signals without spectrum distortion. In this paper, the authors propose to extend the possibilities of interleaving to improve PAPR reduction, to use a new coding of interleaver keys at the transmitter and a robust decoding procedure at the receiver. In order not to degrade the data rate, the use of null subcarriers to transmit side information to the receiver is proposed and evaluated. Simulation results in the context of the WLAN 802.11a standard in the presence of a nonlinear power amplifier model with memory, show a reduction of PAPR of approximately 5.2 dB, and an improvement of bit error rate and error vector magnitude of about 2 decades and 4% respectively, while respecting the spectral mask specification.