| 摘要 |
PURPOSE:To acquire a frequency deviation between transmission and reception even when the deviation is larger than a half of a transmission frequency by detecting a phase at least twice for one data so as to expand a range of a frequency deviation between the transmission and reception able to be acquired up to at least a frequency range of the transmission speed. CONSTITUTION:The system consists of a terminal 1 for a reception signal subject to direct spread, a low pass filter 2, an A/D converter 3, a correlation device 4, a phase detector 5, a VCXO (Voltage Controlled Crystal Oscillator) 6, a multiplier 7, a pi/2 phase shifter 8 and an adder 9. Thus, a phase is detected at least twice for one data to expand a range of a frequency deviation between the transmission and reception able to be acquired up to at least a frequency range of the transmission speed. Thus, when the frequency deviation between the transmission and reception is at least within a frequency range of the transmission speed, the phase deviation for one data is less than + or -90 deg. and able to be acquired. |
