Title :
A coding-theoretical view on code division multiple access: two new constructions of CDMA codes
Author :
Lundqvist, Anders ; Anderson, Per-Olof
Author_Institution :
Dept. of Electr. Eng., Linkoping Univ., Sweden
Abstract :
Coding techniques for the multiple-access problem are investigated. Two constructions of code sequences are considered, one for the OR channel and one for the Gaussian channel. A new construction of codes for the OR channel, which belongs to the family of cyclically permutable (CP) codes also known as optical orthogonal codes, removes the constraint of frame synchronization. This new construction of CP codes can be derived from known codes for the synchronous situation. The construction of codes for the Gaussian channel is for the synchronous case and has an exponential increase in the number of sequences when the length increases. For both constructions, we discuss the ability to handle noise and near-far effects
Keywords :
Gaussian channels; code division multiple access; cyclic codes; encoding; sequences; CDMA codes; Gaussian channel; OR channel; code division multiple access; code sequences; coding; cyclically permutable codes; near-far effects; noise effects; optical orthogonal codes; sequence length; Codes; Communication system control; Delay effects; Fading; Feedback; Gaussian channels; Mobile communication; Multiaccess communication; Performance analysis; Protocols;
Conference_Titel :
Vehicular Technology Conference, 1994 IEEE 44th
Conference_Location :
Stockholm
Print_ISBN :
0-7803-1927-3
DOI :
10.1109/VETEC.1994.345066
