author = {D. Nikolai and K.-D. Kammeyer},
  year = {1997},
  month = {Sep},
  title = {BER Analysis of a Novel Hybrid Modulation Scheme for Noncoherent DS-CDMA Systems},
  volume = {2},
  pages = {256-260},
  URL = {http://ieeexplore.ieee.org/Xplore/defdeny.jsp?url=/iel3/4928/13700/00630882.pdf&arnumber=630882&code=2},
  address={Helsinki, Finland},
  abstract={A novel DS-CDMA transmission scheme combining the two well-known techniques of M-ary orthogonal and differential PSK-modulation is presented. This "hybrid" scheme is applicable to the noncoherent uplink of the IS-95 system where up to now only M-ary modulation is used. The additional, PSK-modulated data show a slightly increased bit error rate (BER) compared to the data from M-ary modulation. However, the overall degradation caused hereby is far outweighed by the gain achieved by a higher spreading factor.  Analytical results confirmed by simulations yield an improvement of approximately 1.0 dB in terms of Eb/No on a Rayleigh fading channel when no channel coding is used.  This considerable gain is achieved upon only slight modification of the conventional modulation/demodulation procedure at a low additional complexity.  It will be demonstrated that the IS-95 system is not properly designed since the full exploitation of noncoherent demodulation techniques results in a gain of nearly 2.0 dB. nk97_paper.ps.gz},
  booktitle={IEEE 8th International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC 97)}