PERFORMANCE ANALYSIS OF OPTICAL RECEIVERS WITH SPACE DIVERSITY RECEPTION

The performance of digital and analogue direct-detection optical recei vers with space diversity reception is analysed. The cumulative probab ility distribution of the received signal is calculated for M-branch d iversity and equal-gain combining receivers. For a given probability o f detection, the permissible threshold detection level is shown to inc rease with the number of diversity branches. The improvement in carrie r-to-noise ratio (CNR) is shown to be higher for selection diversity c ompared to combining diversity detection. Optimum diversity array spac ing is calculated; this shows the practicality of space diversity syst ems.