Method and apparatus for phase reference tracking of digital phase modulated signals in the receiver

A method used for phase reference tracking of digital phase modulated signals in the receiver, comprising the steps of:

• converting a received complex signal to the received phase rn;
• feeding the received phase rn to a phase reference tracking unit;
• producing an estimated transmit phase {tilde over (s)}n from the phase reference tracking unit;
• feeding the estimated transmit phase {tilde over (s)}n to a coherent decoder;
• and
• producing symbol ân from the coherent decoder,
• wherein the procedure of producing an estimated transmit phase {tilde over (s)}n further comprising the steps of:
• subtracting a previous phase reference estimate {tilde over (θ)}n-1 from a received phase rn;
• adding a delay (d) to an estimated transmit phase {tilde over (s)}n;
• producing a tracking error εn by subtracting a re-modulation phase with a delay (d)ŝn-d from a re-modulation phase with a delay (d)ŝn-d;
• scaling the tracking error εn by a value of β;
• adding the scaled of tracking error βεn with a previous phase correction factor {tilde over (θ)}′n-1 and derive a phase correction factor {tilde over (θ)}′n;
• scaling the tracking error εn by a value of α;
• adding the scaled of tracking error αεn with the phase correction factor {tilde over (θ)}′n;
• and
• adding the scaled of tracking error αεn, with the phase correction factor {tilde over (θ)}′n with the previous phase reference estimate {tilde over (θ)}n-1 and derive the phase reference estimate {tilde over (θ)}n;
• wherein the delay (d) is used for generating the estimated transmit phase {tilde over (s)}n with correct timing.

A method used for phase reference tracking of digital phase modulated signals in the receiver, comprising the steps of:

• converting a received complex signal to the received phase rn;
• feeding the received phase rn to a phase reference tracking unit;
• producing an estimated transmit phase {tilde over (s)}n from the phase reference tracking unit;
• feeding the estimated transmit phase {tilde over (s)}n to a coherent decoder;
• and
• producing a decoded symbol ân from the coherent decoder,
• wherein the procedure of producing a decoded symbol ân further comprising the steps of:
• feeding an estimated transmit phase {tilde over (s)}n to a coherent decoder;
• de-mapping the estimated transmit phase {tilde over (s)}n;
• producing a decoded symbol ân;
• mapping the decoded symbol ân;
• and
• producing a re-modulation phase signal ŝn;
• wherein the re-modulation phase signal ŝn is feed to a phase reference tracking unit and used for the calculation of a tracking error εn.

An apparatus used for phase reference tracking of digital phase modulated signals in the receiver, comprising:

• a complex-to-phase converter, used for converting the in-phase (In) and the quadrature (Qn) components of a received complex signal to a received phase rn;
• a phase reference tracking unit, electrically connected to the complex-to-phase converter, used for producing an estimated transmit phase {tilde over (s)}n;
• and
• a coherent decoder, electrically connected to the phase reference tracking unit, used for producing a decoded symbol ân and sending a re-modulation phase signal ŝn to the phase reference tracking unit,
• wherein the phase reference tracking unit further comprising:
• a first subtracter, used for subtracting the previous phase reference estimate {tilde over (θ)}n-1 from the received phase rn and producing the estimated transmit phase {tilde over (s)}n;
• a second subtracter, electrically connected to the coherent decoder, used for subtracting the a re-modulation phase signal ŝn from the estimated transmit phase {tilde over (s)}n and producing a tracking error εn;
• a first multiplier, electrically connected to the second subtracter, used for scaling the tracking error εn by a value of β;
• a first adder, electrically connected to the first multiplier, used for adding a scaled tracking error βεn and a previous phase correction factor {tilde over (θ)}′n-1;
• a first sample delay unit, electrically connected to the first adder, used for the taking the phase correction factor {tilde over (θ)}′n to the previous state of {tilde over (θ)}′n-1 and providing a feedback signal of previous phase correction factor {tilde over (θ)}′n-1 to the first adder;
• a second multiplier, electrically connected to the second subtracter, used for scaling the tracking error εn by a value of α;
• a second adder, electrically connected to the second multiplier, used for adding a scaled tracking error αεn and the phase correction factor {tilde over (θ)}′n;
• a third adder, electrically connected to the second adder, used for adding the previous phase reference estimate {tilde over (θ)}n-1, the scaled tracking error αεn and the phase correction factor {tilde over (θ)}′n;
• and
• a second sample delay unit, electrically connected to the second adder, used for the taking the phase reference estimate {tilde over (θ)}n to the previous state {tilde over (θ)}n-1 and providing a feedback signal of previous reference estimate {tilde over (θ)}n-1 to the third adder and the first subtracter.

An apparatus used for phase reference tracking of digital phase modulated signals in the receiver, comprising:

• a complex-to-phase converter, used for converting the in-phase (In) and the quadrature (Qn) components of a received complex signal to a received phase rn;
• a phase reference tracking unit, electrically connected to the complex-to-phase converter, used for producing an estimated transmit phase {tilde over (s)}n;
• and
• a coherent decoder, electrically connected to the phase reference tracking unit, used for producing a decoded symbol ân and sending a phase singal ŝn to the phase reference tracking unit,
• wherein the phase reference tracking unit further comprising:
• a first subtracter, used for subtracting the previous phase reference estimate {tilde over (θ)}n-1 from the received phase rn and producing the estimated transmit phase {tilde over (s)}n;
• a coherent decoder, electrically connected to the first subtracter, used for compensating the delay (d) caused in the coherent decoder and generating the estimated transmit phase {tilde over (s)}n with correct timing;
• a second subtracter, electrically connected to the coherent decoder, used for subtracting the a re-modulation phase signal with a delay (d) ŝn-d the estimated transmit phase with a delay (d) {tilde over (s)}n-d and producing a tracking error εn;
• a first adder, electrically connected to the first multiplier, used for adding a scaled tracking error βεn and a previous phase correction factor {tilde over (θ)}′n-1;
• a first sample delay unit, electrically connected to the first adder, used for the taking the phase correction factor {tilde over (θ)}′n to the previous state of {tilde over (θ)}′n-1 and providing a feedback signal of previous phase correction factor {tilde over (θ)}′n-1 it the first adder;
• a second multiplier, electrically connected to the second subtracter, used for scaling the tracking error εn by a value of α;
• a second adder, electrically connected to the second multiplier, used for adding a scaled tracking error αεn and the phase correction factor {tilde over (θ)}′n;
• a third adder, electrically connected to the second adder, used for adding the previous phase reference estimate {tilde over (θ)}n-1, the scaled tracking error αεn and the phase correction factor {tilde over (θ)}′n;
• and
• a second sample delay unit, electrically connected to the second adder, used for the taking the phase reference estimate {tilde over (θ)}n to the previous state {tilde over (θ)}n-1 and providing a feedback signal of previous reference estimate {tilde over (θ)}n-1 to the third adder and the first subtracter;
• wherein the delay (d) of estimated transmit phase {tilde over (s)}n is caused by the coherent decoder and results an estimated transmit phase with a delay (d) {tilde over (s)}n-d.