Scale time offset robust modulation for code division multiaccess

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Scopus citations


This paper introduces and analyzes Scale-Time Offset Robust Modulation (STORM) for use in code division multiaccess (CDMA) systems using spread quadrature phase shift keying (QPSK) to increase the capacity of a CDMA network. Since current commercial CDMA systems have dedicated spectrum, the capacity is primarily limited by the interference of other CDMA users; thus, power control and multiuser interference mitigation are the focus of CDMA capacity enhancements. Although extensive research in these areas continues, significant, robust, practical capacity enhancements have been difficult to realize for existing commercial CDMA systems such as Wideband-CDMA (WCDMA). STORM offers potential to practically enhance the capacity of CDMA systems by robustly realizing more rapid power control and more efficient multiuser interference mitigation. STORM is incorporated into CDMA by modifying the the inphase spreading code (Gold or Kasami) and using the modified code to replace the quadrature spreading code, and the inphase code is transmitted unperturbed. Multiaccess interference properties for the Gold and Kasami spreading codes are well known. Since modifications to these sequences change the well known properties, this paper begins to evaluate the multiaccess interference for the STORM enhanced Gold and Kasami codes. The maximum code cross-correlations are evaluated for a group of eighty users generated from codes obtained from the wideband-CDMA (WCDMA) specification. In addition, STORM codes were generated and the analytically based probability of error is evaluated in a manner consistent with archival literature. The maximum cross-correlation between codes of a complete sequence increases but remains approximately one percent of the peak autocorrelation value, and the subsequence correlation values are consistent before and after the application of STORM. Subsequences are used as the scrambling codes for WCDMA. Using the archival literature method for determining the bit error probability, the probability of error is the same for the STORM codes and Gold codes of length 511 and up to fifty users.

Original languageEnglish (US)
Title of host publicationMILCOM 2009 - 2009 IEEE Military Communications Conference
StatePublished - Dec 1 2009
Event2009 IEEE Military Communications Conference, MILCOM 2009 - Boston, MA, United States
Duration: Oct 18 2009Oct 21 2009

Publication series

NameProceedings - IEEE Military Communications Conference MILCOM


Other2009 IEEE Military Communications Conference, MILCOM 2009
Country/TerritoryUnited States
CityBoston, MA

All Science Journal Classification (ASJC) codes

  • Electrical and Electronic Engineering


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