Performance comparison of various pulse position modulation in wireless laser communication

In order to compare the performance of various types of pulse position modulation,the coding structure,average transmitted power,bandwidth requirements,transmission rate,power spectral density and channel capacity were compared.Their characteristics and application fields were analyzed.The results show that,on off keying is easy to implement,but power utilization ratio is too low;pulse position modulation improves power utilization ratio but bandwidth availability ratio is low and it need symbol synchronization;digital pulse interval modulation shortens the length of the symbols,it has high bandwidth availability ratio and does not need symbol synchronization,but it is too complex;dual header pulse interval modulation improves the bandwidth efficiency and transmission capacity and do not need symbol synchronization,greatly simplify the complexity of the system implementation.