Abstract:
A theoretical analysis is carried out to evaluate the efficiency of two different
dispersion compensation schemes, viz. lump compensation and even
compensation to minimize the effect of group velocity dispersion (GVD ) on
the performance of an optical CPFSK point to point transmission system using
MZI based direct detection receiver. The analysis is extended to linecoded
CPFSK system with three line-coding schemes, viz. Alternate mark inversion
(AMI), Miller code or Delay modulation (DM) and Manchester code(MC). The
analysis is also carried out to find out the impact of SPM with GVD
compensation.
The analysis includes the effect of accumulated amplifiers spontaneous
emission (ASE) noise, signal -ASE noise, ASE-ASE beat noise, laser phase
noise and receiver noise. The statistics of the phase fluctuations due to
chromatic dispersion in the presence of filtering effect and laser phase noise
are determined analytically and is used to determine the bit error probability of
the direct detection FSK receiver. The analysis is first carried out for NRZ data
pattern and then extended to line-coded data patterns with three different linecoding
schemes, viz. AMI, DM, MC to investigate the effectiveness of the linecoding
schemes in presence of dispersion. Following the theoretical analysis,
the bit error rate (BER) performance of the optical link is evaluated for NRZ .
and line-coded data pattern at a bit rate of 10 Gb/s for different system
parameters. The power penalty suffered by the system due to the system
imperfections mentioned above at BER=lO.9 is evaluated. The improvement in
system performance due to the use of compensation schemes is then determined
for NRZ data. Performance degradation due to SPM is also evaluated.
