Performance Comparison of GDMA, LDS-CDMA, and SCMA for Transmissions over Rayleigh Fading Channels
Journal
IEEE Vehicular Technology Conference
Journal Volume
2021-September
Date Issued
2021
Author(s)
Abstract
Gain division multiple access (GDMA), low density spreading code division multiple access (LDS-CDMA) and Sparse code multiple access (SCMA) are non-orthogonal multiple access methods, where SCMA is a method derived from LDS-CDMA with a special design of signal constellation. We compare their performances for transmission over Rayleigh fading channels. Simulation results show that the special constellation design of SCMA does not provide any gain in Rayleigh fading channels. We show that the error performances of a 6-user LDS-CDMA scheme based on 4 resources can be evaluated by applying diversity-2 concept to the 3-user GDMA based on a single resource. However, by using more resources and error-correcting codes, GDMA can also achieve diversity and hence provide error rates similar to LDS-CDMA. In addition, GDMA has the advantage of low complexity. ? 2021 IEEE.
Event(s)
94th IEEE Vehicular Technology Conference, VTC 2021-Fall
Subjects
CSI
GDMA
LDS-CDMA
SCMA
Errors
Fading channels
Rayleigh fading
Code-division multiple-access
Gain division multiple access
Low density spreading
Low density spreading code division multiple access
Multiple access
Sparse code multiple access
Sparse codes
Spreading codes
Code division multiple access
Type
conference paper