Adaptive digital predistortion linearization and feed-forward correction of RF power amplifier

Claim 3

A method according to claim 1, further including the steps of: (g) performing RF amplifier distortion measurements on said digitized signal input and output signals provided in step (a), so as to generate second weights representative of said amplitude and phase distortion; (h) storing said second weights in memory; (i) accessing a respective one of said second weights stored in memory in accordance with an input signal to be amplified by said RF power amplifier; (j) modifying said input signal in accordance with said respective one of said second weights accessed from memory to derive a feed-forward correction signal; and (k) combining said feed-forward correction signal with an amplified output signal from said RF power amplifier.

Claim 4

A method according to claim 2, wherein step (g) comprises adaptively adjusting said second weights in accordance with said successive ones of said RF amplifier distortion measurements on said digitized input and output signals.

Claim 5

A method according to claim 1, wherein step (b) comprises adaptively adjusting said first weights in accordance with said successive ones of said RF amplifier distortion measurements on said digitized input and output signals.

Claim 6

A method according to claim 2, wherein step (k) includes amplifying said feed-forward correction signal by means of an auxiliary RF error amplifier having an operational power range less than that of said RF power amplifier, and coupling the amplified feed-forward correction signal to the amplified output signal from said RF power amplifier.

Claim 7

A method according to claim 2, wherein said first and second weights are based upon envelope-dependency of distortion-introducing behavior of said RF power amplifier.

Claim 8

A method according to claim 1, wherein step (b) comprises deriving said first complex weights in accordance with the complex division of complex envelopes of said input signal by said output signal, and wherein step (e) comprises multiplying the complex envelope of said RF input signal by said respective one of said first complex weights accessed in step (d) to derive said predistorted input signal.

Claim 9

A method according to claim 7, wherein step (g) comprises deriving said second complex weights in accordance with the complex division of complex envelopes of said input signal by said output signal, and wherein step (j) comprises multiplying the complex envelope of said RF input signal by said respective one of said second weights accessed in step (i) to derive said feed-forward correction signal.

Claim 10

A method according to claim 2, wherein steps (d) and (i) respectively comprise accessing first and second weights stored in memory in dependence upon the baseband power in said input signal to be amplified by said RF power amplifier.

Claim 11

A method according to claim 9, wherein steps (d) and (i) respectively comprise accessing first and second weights stored in memory which have the same baseband power as said input signal to be amplified by said RF power amplifier.

Claim 12

A method according to claim 2, wherein steps (b) and (g) comprise generating respective read out address codes for accessing first and second weights stored in memory in accordance with the magnitude of the complex waveform of said input signal.

Claim 13

A method according to claim 11, wherein step (e) comprises multiplying an input signal to said RF power amplifier by a respective one of said first weights read out from memory to derive said predistorted input signal.

Claim 14

A method according to claim 11, wherein step (j) comprises multiplying an input signal to said RF power amplifier by a respective one of said second weights read out from memory to derive said feed-forward correction signal.

Claim 15

A method according to claim 1, wherein step (b) comprises generating a quotient representative of a ratio of said input signal and said output signal, and multiplying said quotient by said respective one of said first weights to produce an adaptively adjusted value of said respective one of said first weights.

Claim 16

A method according to claim 5, wherein step (g) comprises generating a quotient representative of a ratio of said input signal and said output signal, subtracting said quotient from an alignment vector and multiplying said quotient by an output alignment vector which is effective to align the output of said auxiliary error amplifier with the output of said RF power amplifier in amplitude and phase, to produce an adaptively adjusted value of said respective one of said second weights.

Claim 17

A method according to claim 2, wherein steps (c) and (h) comprise generating respective write address codes for storing first and second weights in memory in accordance with a delayed version of the magnitude of the complex waveform of said input signal.

Claim 20

A method according to claim 17, wherein step (b) comprises adaptively adjusting said feed-forward correction weights in accordance with said successive ones of said RF amplifier distortion measurements on said digitized input and output signals.

Claim 21

A method according to claim 17, wherein step (f) includes amplifying said feed-forward correction signal by means of an auxiliary RF error amplifier having an operational power range less than that of said RF power amplifier, and coupling the amplified feed-forward correction signal to the amplified output signal from said RF power amplifier.

Claim 22

A method according to claim 17, wherein said feed-forward correction weights are based upon envelope-dependency of distortion-introducing behavior of said RF power amplifier.

Claim 23

A method according to claim 17, wherein step (b) comprises performing RF amplifier distortion measurements on the complex envelopes of the RF amplifier's input and output signals to generate feed-forward complex weights.

Claim 24

A method according to claim 21, wherein step (b) comprises deriving said feed-forward correction complex weights in accordance with the complex division of complex envelopes of said input signal by said output signal.

Claim 25

A method according to claim 17, wherein step (d) comprises accessing feed-forward correction weights stored in memory in dependence upon the baseband power in said input signal to be amplified by said RF power amplifier.

Claim 26

A method according to claim 17, wherein step (b) comprises generating respective read out address codes for accessing feed-forward correction weights stored in memory in accordance with the magnitude of the complex waveform of said input signal.

Claim 27

A method according to claim 24, wherein step (e) comprises multiplying an input signal to said RF power amplifier by a respective one of said second weights read out from memory to derive said feed-forward correction signal.

Claim 28

A method according to claim 17, wherein step (b) comprises generating a quotient representative of a ratio of said input signal and said output signal, subtracting said quotient from an alignment vector and multiplying said quotient by an output alignment vector which is effective to align the output of said auxiliary error amplifier with the output of said RF power amplifier in amplitude and phase, to produce an adaptively adjusted value of said respective one of said second weights.

Claim 29

A method according to claim 17, wherein step (c) comprises generating a write address codes for storing feed-forward weights in memory in accordance with a delayed version of the magnitude of the complex waveform of said input signal.

Claim 30

A signal processing arrangement for correcting for amplitude and phase distortion in an RF power amplifier comprising: a signal coupler which is operative to provide a digitized input signal representative of the complex envelope of a signal component to be amplified by said RF power amplifier and a digitized output signal representative of the complex envelope of an amplified signal component derived from said RF power amplifier; a distortion measurement unit which is operative to perform RF amplifier distortion measurements on said digitized input signal and said digitized output signal so as to generate first weights representative of said amplitude and phase distortion; a first memory which stores said first weights; a memory access unit which is operative to controllably read out a respective one of said first weights from said first memory in accordance with an input signal to be amplified by said RF power amplifier; and a predistortion unit which is operative to predistort said input signal to said RF power amplifier in accordance with said respective one of said first weights read out by said first memory access unit so as to generate a predistorted input signal, which is applied to said RF amplifier.

Claim 31

A signal processing arrangement for correcting for amplitude and phase distortion in an RF power amplifier comprising: a signal coupler which is operative to provide a digitized input signal representative of the complex envelope of a signal component to be amplified by said RF power amplifier and a digitized output signal representative of the complex envelope of an amplified signal component derived from said RF power amplifier; a distortion measurement unit which is operative to perform RF amplifier distortion measurements on said digitized input signal and said digitized output signal so as to generate first weights representative of said amplitude and phase distortion; a first memory which stores said first weights; a memory access unit which is operative to controllably read out a respective one of said first weights from said first memory in accordance with an input signal to be amplified by said RF power amplifier; and a predistortion unit which is operative to predistort said input signal to said RF power amplifier in accordance with said respective one of said first weights read out by said first memory access unit so as to generate a predistorted input signal, which is applied to said RF amplifier.

Claim 32

A signal processing arrangement according to claim 28, further including a second memory and a feed-forward correction unit, and wherein said distortion measurement unit is further operative to perform RF amplifier distortion measurements on said digitized input signal and said digitized output signal to generate second weights representative of said amplitude and phase distortion, which are stored in said second memory, and wherein said memory access unit is operative to controllably read out a respective one of said second weights from said second memory in accordance with an input signal to be amplified by said RF power amplifier, and wherein said feed-forward correction unit is operative to modify said input signal in accordance with said respective one of said second weights to derive a feed-forward correction signal, and to combine said feed-forward correction signal with an amplified output signal from said RF power amplifier.

Claim 33

A signal processing arrangement according to claim 29, wherein said distortion measurement unit is operative to adaptively adjust said first and second weights in accordance with said successive ones of said digitized input signal and said digitized output signal.

Claim 34

A signal processing arrangement according to claim 30, wherein said feed-forward correction unit includes an auxiliary RF error signal amplifier having an operational power range less than that of said RF power amplifier, and which is operative to amplify said feed-forward correction signal, with the amplified feed-forward correction signal being combined with the amplified output signal from said RF power amplifier.

Claim 35

A signal processing arrangement according to claim 29, wherein said first and second weights are based upon envelope-dependency of distortion-introducing behavior of said RF power amplifier.

Claim 36

A signal processing arrangement according to claim 29, wherein said distortion measurement unit is operative to derive said first and second weights by performing complex division of complex envelopes of said input signal and output signal.

Claim 37

A signal processing arrangement according to claim 33, wherein said predistortion unit is operative to predistort said input signal to said RF power amplifier by multiplying the complex envelope of said input signal by said respective one of said first weights accessed from said first memory to derive said predistorted input signal.

Claim 38

A signal processing arrangement according to claim 33, wherein said feed-forward correction unit is operative to generate said feed-forward correction signal by multiplying the complex envelope of said input signal by said respective one of said second weights accessed from said second memory.

Claim 39

A signal processing arrangement according to claim 28, wherein said memory access unit is operative to controllably read out a respective one of said first weights from said first memory in dependence upon the baseband power in said input signal to be amplified by said RF power amplifier.

Claim 40

A signal processing arrangement according to claim 28, wherein said memory access unit is operative to generate a read out address code for accessing a first weight stored in said first memory in accordance with the magnitude of the complex waveform of said input signal.

Claim 41

A signal processing arrangement according to claim 37, wherein said predistortion unit is operative to multiply an input signal to said RF power amplifier by a respective one of said first weights read out from said first memory to derive said predistorted input signal, and wherein said feed-forward correction unit is operative to multiply an input signal by a respective one of said second weights read out from said second memory to derive said feed-forward correction signal.

Claim 42

A signal processing arrangement according to claim 28, wherein said distortion measurement unit is operative to generate quotient signals representative of ratios of said input signal and said output signal, and to multiply said quotient signals by first and second weights to produce an adaptively adjusted values of said first and second weights.

Claim 43

A signal processing arrangement according to claim 29, wherein said memory access unit is operative to generate respective write address codes for storing first and second weights in said first and second memories in accordance with a delayed version of the magnitude of the complex waveform of said input signal.

Claim 44

A signal processing arrangement for correcting for amplitude and phase distortion in an RF power amplifier comprising: a signal coupler which is operative to provide a digitized input signal component to be amplified by said RF power amplifier and a digitized amplified output signal component derived from said RF power amplifier; a distortion measurement unit which is operative to perform RF amplifier distortion measurements on said digitized signal components so as to generate feed-forward correction weights representative of said amplitude and phase distortion; a memory which stores said feed-forward correction weights; a memory access unit which is operative to controllably read out a respective one of said feed-forward correction weights from memory in accordance with an input signal to be amplified by said RF power amplifier; and a feed-forward correction unit including an auxiliary RF error amplifier which is operative to modify said input signal to said RF power amplifier in accordance with said respective one of said feed-forward correction weights read out of memory and to generate an amplified modified input signal, which is combined with the output of said RF amplifier.

Claim 45

A signal processing arrangement for correcting for amplitude and phase distortion in an RF power amplifier comprising: a signal coupler which is operative to provide a digitized input signal component to be amplified by said RF power amplifier and a digitized amplified output signal component derived from said RF power amplifier; a distortion measurement unit which is operative to perform RF amplifier distortion measurements on said digitized signal components so as to generate feed-forward correction weights representative of said amplitude and phase distortion; a memory which stores said feed-forward correction weights; a memory access unit which is operative to controllably read out a respective one of said feed-forward correction weights from memory in accordance with an input signal to be amplified by said RF power amplifier; and a feed-forward correction unit including an auxiliary RF error amplifier which is operative to modify said input signal to said RF power amplifier in accordance with said respective one of said feed-forward correction weights read out of memory and to generate an amplified modified input signal, which is combined with the output of said RF amplifier.

Claim 46

A signal processing arrangement according to claim 41, wherein said distortion measurement unit is operative to adaptively adjust said feed-forward correction weights in accordance with said successive ones of said digitized signal components.

Claim 47

A signal processing arrangement according to claim 41, wherein said auxiliary RF error signal amplifier has an operational power range less than that of said RF power amplifier.

Claim 48

A signal processing arrangement according to claim 41, wherein said feed-forward correction weights are based upon envelope-dependency of distortion-introducing behavior of said RF power amplifier.

Claim 49

A signal processing arrangement according to claim 41, wherein said distortion measurement unit is operative to derive said feed-forward correction weights by performing complex division of complex envelopes of said input signal and said output signal.

Claim 50

A signal processing arrangement according to claim 44, wherein said feed-forward correction unit is operative to generate said feed-forward correction signal by multiplying the complex envelope of said input signal by a feed-forward correction weight accessed from memory.

Claim 51

A signal processing arrangement according to claim 41, wherein said memory access unit is operative to controllably read out a respective one of said feed-forward correction weights from memory in dependence upon the baseband power in said input signal to be amplified by said RF power amplifier.

Claim 52

A signal processing arrangement according to claim 47, wherein said memory access unit is operative to read out from a feed-forward correction weight having the same baseband power as said input signal to be amplified by said RF power amplifier.

Claim 53

A signal processing arrangement according to claim 41, wherein said memory access unit is operative to generate a read out address code for accessing a first weight stored in said first memory in accordance with the magnitude of the complex waveform of said input signal.

Claim 54

A signal processing arrangement according to claim 41, wherein said distortion measurement unit is operative to generate quotient signals representative of ratios of said input signal and said output signal, and to multiply said quotient signals by said feed-forward correction weights to produce an adaptively adjusted values of said feed-forward correction weights.

Claim 55

A signal processing arrangement according to claim 41, wherein said memory access unit is operative to generate respective write address codes for storing said feed-forward correction weights in memory in accordance with a delayed version of the magnitude of the complex waveform of said input signal.

Claim 56

A signal processing arrangement according to claim 41, wherein said distortion measurement unit is operative to generate a quotient representative of a ratio of said input signal and said output signal, subtract said quotient from an alignment vector and multiplying said quotient by an output alignment vector which is effective to align the output of said auxiliary error RF amplifier with the output of said RF power amplifier in amplitude and phase, to produce an adaptively adjusted value of a feed-forward correction weight.

Claim 57

A signal processing arrangement according to claim 52, wherein said memory access unit is operative to read out a respective one of said feed-forward correction weights from memory in accordance in accordance with temperature.

Claim 58

A signal processing arrangement according to claim 53, wherein said memory access unit includes a leaky integrator.

Claim 59

A method according to claim 1, wherein step (d) comprises accessing said respective one of said first weights in accordance with temperature.

Claim 60

A method according to claim 17, wherein step (d) comprises accessing said respective one of said feed-forward correction weights stored in memory in accordance with temperature.

Claim 61

A signal processing arrangement according to claim 28, wherein said memory access unit is operative to controllably read out said respective one of said first weights from said first memory in accordance with temperature.

Claim 62

A signal processing arrangement according to claim 57, wherein said memory access unit includes a leaky integrator.