2018 年 7 巻 2 号 p. 48-53
To implement K-user multi-rate multi-power transmission in non-orthogonal multiple access systems with successive interference cancellation, a repeat accumulator code serially concatenated with a spreading is employed for each user to implement a variable, low-rate coding. A joint rate and power optimization (RPO) is proposed to maximize the sum rate with error free decoding. Numerical results show that our proposed coding-spreading scheme with joint RPO, supporting the multi-rate transmission with the same structure of encoder, approaches the Shannon limit.
