Method and apparatus for transmitter noise cancellation in an RF communications system

Claim 3

The method of claim 1 wherein said transmitter circuit and said receiver circuit are on a single RF IC chip.

Claim 4

The method of claim 1 wherein said determining a first estimation of said signal leakage comprises disconnecting an antenna of said RF communications system.

Claim 5

The method of claim 3 wherein said determining said first estimation of said signal leakage further comprises connecting a dummy load emulating said antenna.

Claim 6

The method of claim 1 wherein said determining said first estimation of said signal leakage includes tuning said receiver circuit to a clean frequency band.

Claim 7

The method of claim 1 wherein said determining said first estimation of said signal leakage comprises: generating a calibration signal based on a pseudo-random noise sequence; splitting said calibration signal into a first signal and a second signal, wherein said first signal is sent to an estimation circuit and said second signal is further divided into a third signal sent to a dummy antenna load and a fourth signal sent to said estimation circuit; and cross correlating said first signal and said fourth signal in said estimation circuit to produce said first estimation.

Claim 8

The method of claim 6 wherein said determining said second estimation based on said first estimation comprises: splitting said transmit communication signal into a fifth signal and a sixth signal, wherein said fifth signal is sent to said estimation circuit and said sixth signal is sent to an antenna; and using parameters from said first estimation, determining in said estimation circuit said second estimation from said fifth signal.

Claim 11

The method of claim 8 wherein said loop parameters include gain and phase.

Claim 12

The method of claim 8 wherein said transmitter and said receiver are on different IC chips.

Claim 13

The method of claim 8 wherein said transmitter and said receiver are on a single RF IC chip.

Claim 14

The method of claim 8 wherein said step of calibrating said RF IC communications system occurs on power-up of said RF IC communications system.

Claim 15

The method of claim 8 wherein said step of calibrating said RF IC communications system occurs during an event selected from a group consisting of power-up, idle mode, roaming mode, power-off, standby mode, connecting mode, dialing a number, or hand-off.

Claim 16

The method of claim 8 wherein said step of calibrating said RF IC communications system occurs periodically.

Claim 17

The method of claim 8 wherein said step of calibrating said RF IC communications system occurs dynamically during full duplex operation.

Claim 22

A RF communications system that substantially cancels transmitter noise during full duplex operation, comprising: a transmit path coupled to a noise cancellation loop, and further coupled to an antenna when said RF communications system is in full duplex mode; a received path coupled to said noise cancellation loop and further coupled to said antenna and said transmit path when said RF communications system is in full duplex mode; said noise cancellation loop using a predetermined calibration signal to approximate a transmit noise signal from said transmit path and to cancel said transmitter noise from a received signal coupled to said received path.

Claim 23

A RF communications system that substantially cancels transmitter noise during full duplex operation, comprising: a transmit path coupled to a noise cancellation loop, and further coupled to an antenna when said RF communications system is in full duplex mode; a received path coupled to said noise cancellation loop and further coupled to said antenna and said transmit path when said RF communications system is in full duplex mode; said noise cancellation loop using a predetermined calibration signal to approximate a transmit noise signal from said transmit path and to cancel said transmitter noise from a received signal coupled to said received path.

Claim 24

The RF communications system according to claim 18 wherein said noise cancellation loop sets parameters based on said predetermined calibration signal, said parameters used by said noise cancellation loop for generating said transmitter noise approximation.

Claim 25

The RF communications system according to claim 19 wherein said parameters include a phase and a gain.

Claim 26

The RF communications system according to claim 18 wherein said transmit path includes a circuit for converting a transmit signal at an intermediate frequency (IF) to a radio frequency (RF).

Claim 27

The RF communications system according to claim 18 wherein said receive path includes a circuit for converting said receive signal at a radio frequency (RF) to an intermediate frequency (IF).

Claim 28

The RF communications system according to claim 18 wherein said transmit path is coupled to said antenna via a duplexer circuit.

Claim 29

The RF communications system according to claim 23 wherein said receive path is coupled to said antenna via said duplexer circuit.

Claim 32

The method of claim 25 wherein said step of determining a first estimation of transmit noise comprises: generating a calibration signal; splitting said calibration signal into a first signal and a second signal, wherein said first signal is sent to an estimation circuit and said second signal is further divided into a third signal sent to a dummy antenna load via said duplexer and a fourth signal sent to said estimation circuit; and cross correlating said first signal and said fourth signal in said estimation circuit to produce said first estimation.

Claim 33

The method of claim 25 wherein said step of determining said second estimation based on said first estimation comprises: splitting said transmit communication signal into a fifth signal and a sixth signal, wherein said fifth signal is sent to an estimation circuit and said sixth signal is sent to an antenna via said duplexer; and using parameters from said first estimation, determining in said estimation circuit said second estimation from said fifth signal.

Claim 34

The method according to claim 27 wherein said parameters include a phase and a gain.

Claim 35

The method of claim 25 wherein said step of combining said second estimation with said received communications signal, such that said transmit noise is substantially cancelled in said received communications signal, comprises: obtaining a seventh signal from said duplexer comprising said received communications signal and transmit noise from said duplexer; and combining said second estimation with said seventh signal, such that said transmit noise is substantially cancelled in said received communications signal.

Claim 36

A RF IC chip that substantially cancels transmitter noise during full duplex communications, comprising: a calibration path, comprising a transmit path coupled to a noise cancellation loop and via a duplexer to an antenna dummy load, said calibration path for determining parameters associated with an estimate of a first transmitter noise signal from said duplexer, when a calibration signal is sent to said antenna dummy load; and a full duplex operation path, comprising: a first path comprising a transmit path coupled to said duplexer and an antenna for transmitting a first communications signal; a second path comprising a transmit path coupled to said noise cancellation loop for determining an estimate of a second transmitter noise signal, using said parameters and a portion of said first communications signal; and a third path coupled to said antenna and said duplexer for receiving a second communications signal; and a fourth path coupled to said duplexer and a receive path for canceling transmitter noise added by said duplexer to said second communications signal by using said estimate of said second transmitter noise signal.

Claim 37

A RF IC chip that substantially cancels transmitter noise during full duplex communications, comprising: a calibration path, comprising a transmit path coupled to a noise cancellation loop and via a duplexer to an antenna dummy load, said calibration path for determining parameters associated with an estimate of a first transmitter noise signal from said duplexer, when a calibration signal is sent to said antenna dummy load; and a full duplex operation path, comprising: a first path comprising a transmit path coupled to said duplexer and an antenna for transmitting a first communications signal; a second path comprising a transmit path coupled to said noise cancellation loop for determining an estimate of a second transmitter noise signal, using said parameters and a portion of said first communications signal; and a third path coupled to said antenna and said duplexer for receiving a second communications signal; and a fourth path coupled to said duplexer and a receive path for canceling transmitter noise added by said duplexer to said second communications signal by using said estimate of said second transmitter noise signal.

Claim 38

A RF IC chip of claim 30 wherein said parameters include a gain and a phase of said first transmitter noise signal.