US 6,445,745 B1 · Phase encoding methods for handling multiple phase modulated signals on a single channel

Abstract

A method for phase encoding DPSK and N-PSK which maintains phase continuity and which does not require any reference symbols when using N-PSK. A sequence of known DPSK phases are encoded with respect to an initial phase. The N-PSK phases are then all offset by this same initial phase. The known DPSK phases can be used at a receiver to determine a sum consisting of the initial phase and any further phase shift introduced by the channel, and this sum is used to decode the unknown N-PSK phases. The method is more generally applicable to any case where a switch between a phase encoding method which requires an absolute phase reference and a phase encoding method which does not have an absolute phase reference is to be implemented on a single carrier or channel.

Claims19

Dependent claims

A phase encoding method comprising:

encoding a first sequence using a first phase encoding method to produce a first encoded sequence and encoding a second sequence which follows the first sequence using a second phase encoding method to produce a second encoded sequence wherein one of the first and second sequences is known and the other one of the first and second sequences is unknown;
wherein one of the first and second phase encoding methods does not require an absolute phase reference for each encoded phase, and the other one of the first and second phase encoding methods requires an absolute phase reference for each encoded phase which is selected such that there is no phase discontinuity between the end of the first encoded sequence and the second encoded sequence.

Dependencies are inferred from the claim text.

Phase encoding methods for handling multiple phase modulated signals on a single channel

Life of this patent

Phase encoding methods for handling multiple phase modulated signals on a single channel

Life of this patent

Abstract

Claims19