Optical CDMA using trellis RLL code with coset representative

In this paper, the employment of two-dimensional run-length limited code is investigated for time-spreading wavelength-hopping optical CDMA systems. In the proposed architecture, the carrier-hopping prime code is utilized as signature sequences, and it is a symmetric code whose out of phase autocorrelation is zero and the cross-correlation is at most one. Based on the zero autocorrelation sidelobes property, we can apply the two-dimensional ternary symbols to the trellis run-length limited code. To further enhance the free distance of the proposed trellis code, a coset representative is added to the codeword. The multiple access interference and beat noise are the most detrimental factors of system impairment. Apart from the multiple access interference and beat noise, some of the deteriorating impacts of system performance are also taken into consideration, which include thermal noise, shot noise, and relative intensity noise.