Theoretical analysis as well as system simulation of a NRZ/RZ (NRZ and duty cycle 33% 50% 66% RZ) shaped APPM
(2×4 and 4×4) modulated scheme for gamma-gamma distribution turbulent free-space optical communication is done.
Results show lower BER in RZ scheme especially with duty cycle 33%, however the NRZ scheme has higher frequency
efficiency. So both BER performance and frequency efficiency can be synthetically considered to choose a proper
scheme according to simulation results.
T-APPM is combined of TCM (trellis-coded modulation) and APPM (Amplitude-Pulse-position modulation) and
has broad application prospects in space optical communication. Set partitioning in standard T-APPM algorithm has
the optimal performance in a multi-carrier system, but whether this method has the optimal performance in APPM
which is a single-carrier system is unknown. To solve this problem, we first research the atmospheric channel model
with weak turbulence; then a modified T-APPM algorithm was proposed, compared to the standard T-APPM
algorithm, modified algorithm uses Gray code mapping instead of set partitioning mapping; finally, simulate the two
algorithms with Monte-Carlo method. Simulation results showed that, when bit error rate at 10-4, the modified
T-APPM algorithm achieved 0.4dB in SNR, effectively improve the system error performance.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.