Capacity loss in CDMA systems due to the constraint of scalability

We compare the sum capacity of strictly scalable and quasi-scalable CDMA systems. It is demonstrated that the requirement of strict scalability inevitably results in a capacity loss as compared to the optimal quasi-scalable OCDMA/OCDMA signature set.

[1]  Marc Moeneclaey,et al.  Multiple access using two sets of orthogonal signal waveforms , 2000, IEEE Communications Letters.

[2]  Dilip V. Sarwate.  Meeting the Welch Bound with Equality , 1998, SETA.

[3]  J. Massey,et al.  Welch’s Bound and Sequence Sets for Code-Division Multiple-Access Systems , 1993 .

[4]  Thomas M. Cover,et al.  Elements of Information Theory , 2005 .

[5]  Shlomo Shamai,et al.  Spectral Efficiency of CDMA with Random Spreading , 1999, IEEE Trans. Inf. Theory.

[6]  Marc Moeneclaey,et al.  Optimal signature sets for oversaturated quasi-scalable direct-sequence spread-spectrum systems , 2005, IEEE Transactions on Information Theory.

[7]  Marc Moeneclaey,et al.  DS/CDMA with two sets of orthogonal spreading sequences and iterative detection , 2000, IEEE Communications Letters.

[8]  Marc Moeneclaey,et al.  Sum capacity of the OCDMA/OCDMA signature sequence set , 2002, IEEE Communications Letters.

[9]  Marc Moeneclaey,et al.  Extending the capacity of multiple access channels , 2000 .

[10]  Venkat Anantharam,et al.  Optimal sequences and sum capacity of synchronous CDMA systems , 1999, IEEE Trans. Inf. Theory.

[11]  James L. Massey,et al.  Optimum sequence multisets for synchronous code-division multiple-access channels , 1994, IEEE Trans. Inf. Theory.

[12]  Bijan Jabbari,et al.  Spreading codes for direct sequence CDMA and wideband CDMA cellular networks , 1998, IEEE Commun. Mag..

[13]  Lloyd R. Welch,et al.  Lower bounds on the maximum cross correlation of signals (Corresp.) , 1974, IEEE Trans. Inf. Theory.