Design of an off-axis freeform diversity receiver to improve SINR performance of a multi-cell VLC system

Compact monolithic freeform Fresnel receiver front-end for Li-Fi application: a step forward

“…This orientation allows channel separation with distinct FOV for different quadrants. The rear side of each freeform Fresnel quadrant has one converging lens (as ref [7]). The receiver is prepared by mounting the monolithic freeform Fresnel on a ( ) 11.2 11.2 2 mm mm mm  hollow opaque capsule, and four photodiodes designated for each quadrant are placed at the bottom of the cap.…”

“…So far, different receiver geometries have been reported to de-correlate the optical channels [3][4][5][6] and improve signal-to-interference-plusnoise-ratio (SINR). Working in the same direction, recently we have reported the potential of freeform optics to improve SINR performance with a compact ( ) 15.12 15.12 6.7 mm mm mm  receiver geometry [7]. In this study, an off-axis quadrilateral ( ) 30 30    FOV is generated by using the rotationally non-symmetric nature of coplanar freeform lenses.…”

Interference mitigation in multiuserWDM VLCsystems using differential receiver

“…The results showed that reducing the FOV of the Tx and the receiver leads to enhance the signal to interference plus noise ratio (SINR) while using simple photodetector (PD). Free form diversity receiver (FDR) was proposed to reduce the interference between Txs in indoor VLC systems 6 . Four PDs were used in the FDR with taking into account the effect of the orientation on the SINR 6 .…”

“…Free form diversity receiver (FDR) was proposed to reduce the interference between Txs in indoor VLC systems. 6 Four PDs were used in the FDR with taking into account the effect of the orientation on the SINR. 6 In, 7 adaptive modulation was used to mitigate interference between two users while using only two light emitting diodes (LEDs) as Txs.…”

“…6 Four PDs were used in the FDR with taking into account the effect of the orientation on the SINR. 6 In, 7 adaptive modulation was used to mitigate interference between two users while using only two light emitting diodes (LEDs) as Txs. However, using only two LEDs as Txs led to make the level of the interference always lower than the desired signal.…”