An effective Estimation scheme based curvelet de-noising algorithm for wireless optical communications

K Dhana Lakshmi, Y Adisatyanarayana
International Research Journal of Engineering and Technology   unpublished
This describes detection scheme without channel state information for wireless optical communication (WOC) systems in turbulence induced fading channel. The proposed scheme can effectively diminish the additive noise caused by background radiation and photo detector, as well as the intensity scintillation caused by turbulence. In Indoor diffuse optical wireless systems with a limited or no line of-sight (LOS) path the strength of the received signal highly depends on the location of the
more » ... tion of the receiver and objects within the room. Thus, the channel impulse response will vary accordingly. In addition, inter-symbol-interference (ISI) due to multipath limits the data rates compared to LOS links. The additive noise can be mitigated significantly using the modified wavelet threshold de-noising algorithm, and then, the intensity scintillation can be attenuated by exploiting the temporal correlation of the WOC channel. Moreover, to improve the performance beyond that of the maximum likelihood decision, the maximum a posteriori probability (MAP) criterion is considered. Compared with conventional blind detection algorithm, simulation results show that the proposed detection scheme can improve the signal-to-noise ratio (SNR) performance.