Single-photon avalanche diodes (SPADs) capable of single photon detection are promising optical sensors for use as receivers in optical wireless communication (OWC) systems. In SPAD-based receivers, the intersymbol interference (ISI) effect caused by dead time is an important drawback that limits performance. In this thesis, we propose two novel SPAD operation receivers to reduce the ISI effect in SPAD-based OWC. To validate the feasibility of these two modes, we design a free-running SPAD front-end circuit with post-layout transient simulation results. This SPAD circuit is improved by a novel mixed passive-active quench and reset front-end circuit that achieves a very short dead time. Based on the traditional free-running mode, we design the clock-driven mode and time-gated mode to reduce the ISI effect through time-controlled operating signals.
In this work, we develop a new simulation system to assess the ISI effect in On-Off Keying (OOK) modulated communication and pulse position modulated (PPM) communication. To accurately evaluate these three modes, we build a OWC platform to test our proposed SPAD receiver manufactured by TSMC 65 nm process. The Test results demonstrate that the clock-driven mode and time-gated mode receivers can improve the bit error rate (BER) performance in low data rate communication and high data rate high optical power communication, respectively. Moreover, compared to the free-running mode, the two proposed time-controlled modes achieve higher data rate communication and better noise tolerance ability in SPAD-based OWC. / Thesis / Master of Applied Science (MASc) / Optical communication involves using light as a signal to transmit information, and it is currently a highly popular field of research. However, optical receivers used in this type of communication often require specific conditions, which can limit the overall performance of the communication system. To address this issue, we have developed an optical sensor tailored for optical communication. This sensor boasts exceptional sensitivity, allowing it to detect individual particles of light, thereby substantially reducing the demand for signal intensity in the optical communication system.
Moreover, we have devised three operational circuits that enhance the sensor's responsiveness to signals under specific communication conditions. We have created a mathematical model to evaluate the proposed optical sensor and the designed circuits, and subsequently manufactured the optical sensor. Both the simulation results and the actual test outcomes unequivocally demonstrate that our proposed sensor has the potential to enhance the performance of optical communication systems.
| Identifer | oai:union.ndltd.org:mcmaster.ca/oai:macsphere.mcmaster.ca:11375/29153 |
| Date | January 2023 |
| Creators | Liu, Junzhi |
| Contributors | Deen, M. Jamal, Electrical and Computer Engineering |
| Source Sets | McMaster University |
| Language | English |
| Detected Language | English |
| Type | Thesis |
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