A multilevel modulation scheme for high-speed wireless infrared communications

Author

Hranilovic, Steve ; Johns, David A.

Author_Institution

Dept. of Electr. & Comput. Eng., Toronto Univ., Ont., Canada

Volume

6

fYear

1999

fDate

36342

Firstpage

338

Abstract

To investigate short-distance, point-to-point, infrared channels, a test-bench and circuits were constructed to determine the limitations of existing optoelectronics. The results of these measurements are used to formulate a channel model which is employed for the subsequent analysis of candidate bandwidth efficient modulation schemes. A new multilevel modulation scheme, Adaptively Biased QAM (AB-QAM), is proposed which has an asymptotic 3 dB SNR improvement over PAM and a 4.5 dB improvement over QAM for large constellations while maintaining the same bandwidth efficiency. Expressions are derived for the performance of each modulation scheme and are verified in simulation

Keywords

adaptive modulation; optical communication; optical modulation; quadrature amplitude modulation; telecommunication channels; SNR; adaptively biased QAM; bandwidth efficiency; constellation; free-space optical communication; high-speed wireless infrared communication; multilevel modulation; optoelectronic circuit; short-distance point-to-point channel model; simulation; Bandwidth; Circuits; High speed optical techniques; Intensity modulation; Optical fiber communication; Optical modulation; Optical signal processing; Photodiodes; Quadrature amplitude modulation; Wireless communication;

fLanguage

English

Publisher

ieee

Conference_Titel

Circuits and Systems, 1999. ISCAS '99. Proceedings of the 1999 IEEE International Symposium on

Conference_Location

Orlando, FL

Print_ISBN

0-7803-5471-0

Type

conf

DOI

10.1109/ISCAS.1999.780164

Filename

780164