Estimation of NLOS optical wireless communication channels with laser transmitters

Abstract

We propose channel estimation for the optical wireless scattering channel with a Laser Diode transmitter based on sparse pilots. For channel taps {hn} L n=0 , the proposed estimation approach consists of two steps, the estimation of the real part Re(hih * j ) in the first step and the estimation of {hn} L n=0 in the second step. Numerical results show that, compared with conventional channel estimation approach based on second-order moments, the proposed approach shows slight performance gain, and less than one tenth of the computational complexity.

Channel estimation techniques for diffusion-based molecular communications

“…Channel estimation was also studied for non-linear and/or non-AWGN channels especially in optical communication. For example, for a photon-counting receiver, a linear timeinvariant channel model with Poisson noise was considered in [17] and a non-linear channel model with Poisson noise was investigated in [18]. However, the MC channel model considered in this paper is neither linear nor impaired by AWGN and is also different from that in [18].…”

“…Next, we investigate the performances of the optimal and ISI-free training sequence designs developed in Section IV. Here, we employ a computer-based search to find the optimal sequence based on the criterion in (18) where ε = 10 −9 . We consider short sequence lengths, i.e., K ≤ 20, due to exponential increase of the computational complexity of the exhaustive search with respect to the sequence length.…”

“…For example, for a photon-counting receiver, a linear timeinvariant channel model with Poisson noise was considered in [17] and a non-linear channel model with Poisson noise was investigated in [18]. However, the MC channel model considered in this paper is neither linear nor impaired by AWGN and is also different from that in [18]. Therefore, the results known from conventional wireless communication are not directly applicable to MC.…”

Optical Wireless Scattering Channel Estimation for Photon-Counting and Photomultiplier Tube Receivers

“…In the current work, we propose a more rigorous channel tap estimation method for the second stage instead of the heuristic one in [26], prove the convergence of the proposed channel estimation framework, and extend the channel estimation to the PMT receiver.…”

“…Remark: A preliminary channel estimation technique for the model under consideration has been investigated in [26], where the two-stage channel estimation framework has been proposed.…”