J4 ›› 2010, Vol. 37 ›› Issue (3): 423-428.doi: 10.3969/j.issn.1001-2400.2010.03.007

• Original Articles • Previous Articles     Next Articles

Multi-branch fractional multi-bit differential detection for continuous phase modulation

SUN Jin-hua1;WU Xiao-jun2   

  1. (1. State Key Lab. of Integrated Service Networks, Xidian Univ., Xi'an  710071, China;
    2. School of Information Eng., Chang'an Univ., Xi'an  710064, China)
  • Received:2009-01-06 Online:2010-06-20 Published:2010-07-23
  • Contact: SUN Jin-hua E-mail:jhsun@xidian.edu.cn

Abstract:

The multi-branch fractional multi-bit differential detection technique for improving the performance of continuous phase modulation signals is proposed. The distance between different phase states is increased by combination and decision of different multi-bit differential signals. The essence of the technique is physically explained, and a theoretical analysis of the upper bound of the fractional bit duration for maximum performance improvement is conducted. Simulation results and further analysis show that the multi-branch fractional multi-bit differential detection technique increases the distance between phase states compared with 1-bit differential detection and 2-bit differential detection, which leads to the performance improvement; when the fractional bit duration is the maximal duration in which the polarity of the differential signal is the same as the decision symbol, the maximum performance gain can be obtained.

Key words: modulation, continuous phase modulation, differential detection, fractional multi-bit differential detection