Constraint length inflation in fixed high rate convolutional codes and their impact on performance of O-IDMA

Abstract

To cope up with the higher data rate existing in modern communication systems multiple access technologies has been investigated OIDMA (optical interleave division multiple access technology) is one of the prominent technology use to fulfill this demand. Convolutional codes used in OIDMA systems enhance the performances and reduces the bit error rate of the system. In the present paper, the convolutional codes with increasing number of memory elements are used, the constraint length which depends on number of memory elements are increased with a systematic manner and their combined effect on response of OIDMA system has been observed. Tree inter-leavers in taken into account for analysis purpose and BER with increasing number of users is plotted in graphical and tabular manner.