Multi-Rate Access Schemes for MC-CDMA

Optimal Power Distribution Control for Multicode MC-CDMA with Zero-Forcing Successive Interference Cancellation

“…From the above analyses, it can be found that with the optimal PDC, when d −2 k,l ≥ 1/4σ 2 ϑ * k (ϑ * k has to be determined), no power will be allocated to the lth symbol of the kth user, which implies that, unlike the equal BER PDC, which always consumes more power to compensate for higher noise power 6 for achieving the same SNR, the optimal PDC allocates no power to those symbols whose noise power is equal to or higher than a certain level (1/4σ 2 ϑ * k ), while allocating more power for other "better" symbols, to ensure more reliable transmissions. Also, for those symbols whose noise power is less than a certain level (1/4σ 2 ϑ * k ), then from (32), under a chosen ϑ * k , since a 2 * k,l is monotonically increasing with d −2 k,l , more power will be allocated to the symbols with higher noise power to ensure the reliability of earlier detected symbols.…”

“…Multicode MC-CDMA is one of the multirate access schemes in which different symbols of each user are transmitted in parallel by employing different spreading codes. Compared with other multirate access schemes, multicode MC-CDMA presents better performance, higher rate matching capability, and lower complexity [6]. However, the capacity of MC-CDMA is mainly limited by self-interference (SI) 1 and 1 SI denotes the interference among different symbols of the same user.…”

A Novel MIMO SC-DS-CDMA HARQ scheme for Frequency Selective and Time Varying Channels

“…In a broadband multiple access system, multicarrier combined with CDMA (multicarrier code division multiple access MC-CDMA) system have been proposed and This work was supported in part by Samsung Advanced Institute of Technology (SAIT-Korea). extensively researched in the literature [5], [6]. Implementing the MC-CDMA technique in a MIMO system allows the achievement of space and frequency diversity in a multiple access environment.…”