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In this paper, we propose to use spatial pulse position modulation (SPPM), which is the combination of optical spatial modulation (SM) and pulse position modulation (PPM), as a powerful technique to improve the performance of free-space optical communication (FSO) systems. We analyze the performance of proposed system taking into account most major effects of FSO channel including geometric spreading...
In this paper, we analyze the performance of multihop free-space optical communication (FSO) systems over strong turbulence fading channels together with misalignment (pointing error) effects. The analysis is carried out under the assumption that turbulence channels are modeled by Gamma-Gamma distribution and multihop transmission is based on symbol decode-and-forward relays. We formulate a closed-form...
In this paper, a model of Gaussian pulse propagation over atmospheric turbulence channel is used to comprehensively analyze the performance of PPM-based free-space optical communication (FSO) systems with APD receiver. This model simultaneously takes into account all effects of atmospheric turbulence including intensity fluctuation and pulse broadening, which has not been considered in previous works...
In OCDMA systems, pulse position modulation (PPM) and multi-code modulation (MCM) have been proven as efficient methods for respectively mitigating multiple access interference (MAI) and dispersion. In this paper, we propose to combine PPM and MCM to create a novel modulation scheme, multi-code pulse position modulation (MCPPM). We then theoretically analyze the performance of the 2-D OCDMA system...
We propose 2-dimensional (2-D) free-space optical (FSO) CDMA system for broadband access networks. The performance of the proposed system is analyzed over strong atmospheric turbulence channels. To mitigate the impact of the strong atmospheric turbulence, channel coding schemes, including Reed-Solomon (R-S) and convolutional (CC) codes, are employed. In the analysis, we derive the upper bound of bit-error...
A new modulation scheme for 2-D OCDMA systems named multi-code modulation (MCM) is proposed in this paper. The key advantage of MCM over the conventional ones is the ability of mitigating simultaneously both multiple access interference and dispersion. We also propose to combine MCM with heterodyne detection, a powerful technique to relax optical beating interference, to obtain better performance...
We propose a novel multiwavelength optical code-division multiple-access (OCDMA) system using multicode modulation (MCM) signaling. For the multicode demodulator, we employ a maximum-likelihood detection and optical hard limiters. The work in this paper theoretically analyzes the performance of the proposed system over linear dispersive channels, while taking into account the impacts of multiple-access...
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