DocumentCode :
867955
Title :
False lock in quadriphase receivers with unequal I- and Q-channel data rates
Author :
Cideciyan, Roy D. ; Wang, James J M ; Lindsey, William C.
Author_Institution :
LinCom Corp., Los Angeles, CA, USA
Volume :
37
Issue :
2
fYear :
1989
fDate :
2/1/1989 12:00:00 AM
Firstpage :
152
Lastpage :
158
Abstract :
Results are presented concerning the noise-free false lock problem in quadriphase receivers with unequal I-channel and Q-channel data rates. It is shown that false lock may occur when the incoming carrier frequency and the loop VCO (voltage-controlled oscillator) frequency differ by an amount that is a linear combination of a quarter of I-channel and Q-channel data rates. General expressions for the false lock performance of quadriphase receivers are given for random as well as periodic data patterns. Specific closed-form expressions for the false lock margin are derived when the arm filters of the quadriphase receivers are single-pole Butterworth filters, and the format of the random data is NRZ (nonreturn-to-zero). Numerical evaluations of false lock margin as a function of the product of 3 dB arm-filter bandwidth and symbol duration are carried out for random data using various arm filters and for different periodic I-channel and Q-channel data patterns
Keywords :
ferromagnetic-paramagnetic transitions; radio receivers; telecommunication channels; 3 dB arm-filter bandwidth; I-channel; NRZ; Q-channel; carrier frequency; closed-form expressions; false lock; loop VCO frequency; nonreturn-to-zero; periodic data patterns; quadriphase receivers; random data; single-pole Butterworth filters; symbol duration; unequal data rates; voltage-controlled oscillator; Clocks; Distortion; Filters; Frequency locked loops; Frequency synchronization; Genetic expression; Helium; Optical signal processing; Quadrature phase shift keying; Voltage-controlled oscillators;
fLanguage :
English
Journal_Title :
Communications, IEEE Transactions on
Publisher :
ieee
ISSN :
0090-6778
Type :
jour
DOI :
10.1109/26.20083
Filename :
20083
Link To Document :
بازگشت