Performance of 3T-ANC based orthogonal frequency-division-multiplexed optical wireless link with pointing error

The average channel capacity, achievable rate, and bit error rate (BER) for orthogonal frequency-division multiplexing-based optical wireless (OFDM-OW) links over Gamma–Gamma-distributed atmospheric channel, with pointing errors, are investigated from an information theory perspective. Building sway, heavy wind, ground motion, or differential heating and cooling could result in misalignment (pointing errors) between transmitter and receiver. A relay-assisted OW communication system, with three-time-slotted analog network coding (3T-ANC) scheme, can be used in non-light-of-sight (NLoS) link situation to make successful communication between the users with improved performance in terms of throughput and BER. In the analysis, we show that the 3T-ANC-based OFDM-OW link gives better BER performance and increased achievable rate with narrow beam width and less normalized jitter value.