A FBG array-based two-dimensional tunable encoder/decoder structure is presented in this paper and the system BER degraded as a result of the autocorrelation peak power degradation of the coder/decoder output in wavelength mismatch is analyzed in detail.The decoder output power and EER of the coder/decoder in corresponding wavelength mismatch with the changes of TS/WH code parameters are simulated.The analytical results show that the system BER remains to be <10-9 for Ph=31 with the wavelength mismatch of 0.1 nm

so the requirements for tuning accuracy by the coder/decoder can be decreased by increasing the number hopping wavelength.