PHASE OFFSET CANCELLATION CIRCUIT

摘要

PURPOSE:To dispense with the use of a training signal by estimating a frequency offset component and an initial phase offset component by arithmetic processing, and cancelling a phase offset by using such values. CONSTITUTION:The phase component thetai of a multivalue phase modulation signal is multiplied by K at a phase multiplication circuit 12. The mean value of the frequency offset component of a multiplication phase signal thetai is found by a differential circuit 14 and an averaging circuit 15. The frequency offset component is eliminated from the signal thetai by an estimation circuit 16 and an initial phase calculation circuit 17, and the mean value of the initial phase offset component is found by an averaging circuit 18. Inter-phase jump is cancelled by an adder 19 and a phase jump correction circuit 20. The phase offset component in the component thetai is cancelled by a phase rotation circuit 23 by using final phase offset quantity SIGMAjj, SIGMAjj found by estimation circuits 21, 22.