A novel constructing method of wavelength-time OOC based on outer product matrix

Since the cardinality of optical orthogonal code (OOC) is small, code length must be increased for the purpose of providing large codeword capacity, which will lead to nonlinearity and reduce the data rate, two-dimensional (2D) wavelength-time (W/T) OOC is more suitable for large capacity system. Aiming at the fact that most of the construction methods of W/T OOC are based on mapping one-dimensional OOCs into 2D W/T codes, the correlation properties for different τ cannot be represented and captured at once, in this paper, a representation of W/T OOC based on outer-product matrix is presented and corresponding constructing method is investigated. Compared with constructing method based on inner product representation, the correlation properties can be detected easily. Simulation results show that the method can easily represent the correlation properties and construct W/T OOCs without restricts to code length, code weight and mark position.