US5910965A — Adaptive predistortion using over-the-hop feedback

Claim 1

Independent Claim 101 words

An improved method of predistorting a signal before transmission of the signal to compensate for nonlinearities introduced when the signal is transmitted to a receiver, the improvement comprising the steps of: (a) evaluating a received signal at a receiver to determine whether the received signal includes nonlinearities, said evaluation including the step of identifying a nonrandom distribution of data in the received signal, the nonrandom distribution being indicative of a nonlinearity; and (b) providing a result of the evaluation back to a transmitter that sent the received signal, the result being used at the transmitter to predistort signals before transmission therefrom.

Claim 2

Dependent Claim 101 words

An improved method of predistorting a signal before transmission of the signal to compensate for nonlinearities introduced when the signal is transmitted to a receiver, the improvement comprising the steps of: (a) evaluating a received signal at a receiver to determine whether the received signal includes nonlinearities, said evaluation including the step of identifying a nonrandom distribution of data in the received signal, the nonrandom distribution being indicative of a nonlinearity; and (b) providing a result of the evaluation back to a transmitter that sent the received signal, the result being used at the transmitter to predistort signals before transmission therefrom.

Claim 3

Dependent Claim 45 words

The method of claim 1 wherein the received signal comprises data bits and selected ones of the data bits define a constellation point, and further comprising the step of determining whether a constellation point is in an area associated with random distribution of constellation points.

Claim 4

Independent Claim 140 words

A method of predistorting an RF signal to compensate for nonlinearities introduced when the RF signal is communicated, the method comprising the steps of: (a) transmitting an RF signal from a first transmitter/receiver to a second transmitter/receiver on a first frequency; (b) extracting nonlinearity data from the RF signal received at the second transmitter/receiver by defining the nonlinearity data as constellation points related to data bits in the received RF signal; defining an area for the constellation points that indicates when a nonlinearity has occurred; and detecting when the constellation points fall into the defined area; (c) transmitting a further RF signal containing the nonlinearity data from the second transmitter/receiver to the first transmitter/receiver on a second frequency; and (d) redistorting RF signals to be transmitted from the first transmitter/receiver on the first frequency by using the received nonlinearity data.

Claim 5

Independent Claim 140 words

A method of predistorting an RF signal to compensate for nonlinearities introduced when the RF signal is communicated, the method comprising the steps of: (a) transmitting an RF signal from a first transmitter/receiver to a second transmitter/receiver on a first frequency; (b) extracting nonlinearity data from the RF signal received at the second transmitter/receiver by defining the nonlinearity data as constellation points related to data bits in the received RF signal; defining an area for the constellation points that indicates when a nonlinearity has occurred; and detecting when the constellation points fall into the defined area; (c) transmitting a further RF signal containing the nonlinearity data from the second transmitter/receiver to the first transmitter/receiver on a second frequency; and (d) redistorting RF signals to be transmitted from the first transmitter/receiver on the first frequency by using the received nonlinearity data.

Claim 6

Dependent Claim 32 words

The method of claim 3 wherein the step of predistorting RF signals comprises the step of: applying predistortion corrections to RF signals to be transmitted after a predetermined number of the detections.

Claim 7

Dependent Claim 62 words

The method of claim 4 wherein the step of predistorting RF signals further comprises the steps of: storing plural of the predistortion corrections that have been applied to RF signals and a corresponding number of the detections resulting therefrom; and applying to RF signals to be transmitted a one of the plural predistortion corrections that provides an acceptable number of the detections.

Claim 8

Dependent Claim 31 words

The method of claim 5 wherein the steps of claim 4 are repeated in order to identify a one of the predistortion corrections that provides the least number of the detections.

Claim 9

Independent Claim 155 words

A method of predistorting an RF signal to compensate for nonlinearities introduced when the RF signal is communicated, the method comprising the steps of: (a) transmitting an RF signal from a first transmitter/receiver to a second transmitter/receiver on a first frequency; (b) extracting nonlinearity data from the RF signal received at the second transmitter/receiver; (c) transmitting a further RF signal containing the nonlinearity data from the second transmitter/receiver to the first transmitter/receiver on a second frequency; and (d) predistorting RF signals to be transmitted from the first transmitter/receiver on the first frequency by using the received nonlinearity data; (e) extracting further nonlinearity data from the further RF signal received at the first transmitter/receiver; (f) transmitting the further nonlinearity data from the first transmitter/receiver to the second transmitter/receiver on the first frequency; and (g) predistorting RF signals to be transmitted from the second transmitter/receiver on the second frequency by applying the received further nonlinearity data thereto.

Claim 10

Independent Claim 155 words

A method of predistorting an RF signal to compensate for nonlinearities introduced when the RF signal is communicated, the method comprising the steps of: (a) transmitting an RF signal from a first transmitter/receiver to a second transmitter/receiver on a first frequency; (b) extracting nonlinearity data from the RF signal received at the second transmitter/receiver; (c) transmitting a further RF signal containing the nonlinearity data from the second transmitter/receiver to the first transmitter/receiver on a second frequency; and (d) predistorting RF signals to be transmitted from the first transmitter/receiver on the first frequency by using the received nonlinearity data; (e) extracting further nonlinearity data from the further RF signal received at the first transmitter/receiver; (f) transmitting the further nonlinearity data from the first transmitter/receiver to the second transmitter/receiver on the first frequency; and (g) predistorting RF signals to be transmitted from the second transmitter/receiver on the second frequency by applying the received further nonlinearity data thereto.

Claim 11

Independent Claim 135 words

A method of predistorting an RF signal to compensate for nonlinearities introduced when the RF signal is communicated, the method comprising the steps of: (a) transmitting an RF signal from a first transmitter/receiver to a second transmitter/receiver on a first frequency; (b) extracting nonlinearity data from the RF signal received at the second transmitter/receiver; (c) transmitting a further RF signal containing the nonlinearity data from the second transmitter/receiver to the first transmitter/receiver on a second frequency; and (d) predistorting RF signals to be transmitted from the first transmitter/receiver on the first frequency by using the received nonlinearity data, said predistorting comprising the steps of receiving the nonlinearity data at a receiver unit and providing the nonlinearity data to a predistorter in a transmitter unit through a reverse channel connection between the receiver and transmitter units.

Claim 12

Independent Claim 135 words

A method of predistorting an RF signal to compensate for nonlinearities introduced when the RF signal is communicated, the method comprising the steps of: (a) transmitting an RF signal from a first transmitter/receiver to a second transmitter/receiver on a first frequency; (b) extracting nonlinearity data from the RF signal received at the second transmitter/receiver; (c) transmitting a further RF signal containing the nonlinearity data from the second transmitter/receiver to the first transmitter/receiver on a second frequency; and (d) predistorting RF signals to be transmitted from the first transmitter/receiver on the first frequency by using the received nonlinearity data, said predistorting comprising the steps of receiving the nonlinearity data at a receiver unit and providing the nonlinearity data to a predistorter in a transmitter unit through a reverse channel connection between the receiver and transmitter units.

Claim 13

Independent Claim 134 words

A method of predistorting an RF signal to compensate for nonlinearities introduced when the RF signal is communicated, the method comprising the steps of: (a) transmitting an RF signal from a first transmitter/receiver to a second transmitter/receiver; (b) extracting nonlinearity data from the RF signal received at the second transmitter/receiver by the steps of, (i) defining the nonlinearity data as constellation points related to data bits in the received RF signal, (ii) defining an area for the constellation points that indicates when a nonlinearity has occurred, and (iii) detecting when the constellation points fall into the defined area; (c) transmitting a further RF signal containing the nonlinearity data from the second transmitter/receiver to the first transmitter/receiver; and (d) predistorting RF signals to be transmitted from the first transmitter/receiver responsive to the received nonlinearity data.

Claim 14

Independent Claim 134 words

A method of predistorting an RF signal to compensate for nonlinearities introduced when the RF signal is communicated, the method comprising the steps of: (a) transmitting an RF signal from a first transmitter/receiver to a second transmitter/receiver; (b) extracting nonlinearity data from the RF signal received at the second transmitter/receiver by the steps of, (i) defining the nonlinearity data as constellation points related to data bits in the received RF signal, (ii) defining an area for the constellation points that indicates when a nonlinearity has occurred, and (iii) detecting when the constellation points fall into the defined area; (c) transmitting a further RF signal containing the nonlinearity data from the second transmitter/receiver to the first transmitter/receiver; and (d) predistorting RF signals to be transmitted from the first transmitter/receiver responsive to the received nonlinearity data.

Claim 15

Dependent Claim 25 words

The method of claim 9 wherein the constellation points are in an 2 N -QAM constellation, where N is an integer from four to eight.

Claim 16

Dependent Claim 36 words

The method of claim 10 wherein the data bits to which the constellation points are related include the two bits immediately following a least significant bit of a package of data in the received RF signal.

Claim 17

Dependent Claim 26 words

The method of claim 9 wherein the RF signal is transmitted on a first frequency and the further RF signal is transmitted on a second frequency.

Claim 18

Independent Claim 180 words

A method of predistorting an RF signal to compensate for nonlinearities introduced when the RF signal is communicated, the method comprising the steps of: (a) transmitting an RF signal from a first transmitter/receiver to a second transmitter/receiver on a first frequency; (b) extracting nonlinearity data from the RF signal received at the second transmitter/receiver, the nonlinearity data including a count of a number of nonlinearities and nonlinearity corrections; (c) communicating the nonlinearity data from a receiver unit in the second transmitter/receiver to a transmitter unit in the second transmitter/receiver through a reverse channel connection between the receiver and transmitter units; (d) transmitting a further RF signal containing the nonlinearity data from the transmitter unit to the first transmitter/receiver on a second frequency; and (e) communicating the nonlinearity data from a further receiver unit in the first transmitter/receiver to a further transmitter unit in the first transmitter/receiver through a reverse channel connection between the further receiver and transmitter units; (f) predistorting RF signals to be transmitted from the further transmitter unit on the first frequency by using the received nonlinearity data.

Claim 19

Independent Claim 180 words

A method of predistorting an RF signal to compensate for nonlinearities introduced when the RF signal is communicated, the method comprising the steps of: (a) transmitting an RF signal from a first transmitter/receiver to a second transmitter/receiver on a first frequency; (b) extracting nonlinearity data from the RF signal received at the second transmitter/receiver, the nonlinearity data including a count of a number of nonlinearities and nonlinearity corrections; (c) communicating the nonlinearity data from a receiver unit in the second transmitter/receiver to a transmitter unit in the second transmitter/receiver through a reverse channel connection between the receiver and transmitter units; (d) transmitting a further RF signal containing the nonlinearity data from the transmitter unit to the first transmitter/receiver on a second frequency; and (e) communicating the nonlinearity data from a further receiver unit in the first transmitter/receiver to a further transmitter unit in the first transmitter/receiver through a reverse channel connection between the further receiver and transmitter units; (f) predistorting RF signals to be transmitted from the further transmitter unit on the first frequency by using the received nonlinearity data.

Claim 20

Dependent Claim 54 words

The method of claim 13 wherein the step of extracting nonlinearity data comprises the steps of; defining the nonlinearity data as constellation points; defining an area for the constellation points that indicates when a nonlinearity has occurred; and detecting when the constellation points fall into the defined area to provide the count of nonlinearities.

Claim 21

Dependent Claim 56 words

The method of claim 14 wherein the step of predistorting RF signals further comprises the steps of: storing plural of the predistortion corrections that have been applied to RF signals and a corresponding count resulting therefrom; and applying to RF signals to be transmitted a one of the plural predistortion corrections that provides an acceptable count.

Claim 22

Dependent Claim 56 words

A signal transmission system for predistorting a signal to compensate for nonlinearities in the communicated signal, the system comprising a processor for evaluating whether an output signal includes nonlinearities without reference to an input signal from which the output signal was derived, and a predistorter for applying results from said processor to a further input signal.

Claim 23

Dependent Claim 56 words

A signal transmission system for predistorting a signal to compensate for nonlinearities in the communicated signal, the system comprising a processor for evaluating whether an output signal includes nonlinearities without reference to an input signal from which the output signal was derived, and a predistorter for applying results from said processor to a further input signal.

Claim 24

Dependent Claim 29 words

The system of claim 16 wherein said processor comprises means for identifying a nonrandom distribution of data in the output signal, the nonrandom distribution being indicative of a nonlinearity.

Claim 25

Dependent Claim 44 words

The system of claim 17 wherein the output signal comprises data bits and selected ones of the data bits define a constellation point, and further comprising means for determining whether a constellation point is in an area associated with random distribution of constellation points.

Claim 26

Dependent Claim 186 words

A signal transmission system for predistorting a signal to compensate for nonlinearities in the communicated signal, the system comprising plural transmitter/receivers, each of which comprises a transmitter unit and a receiver unit: said transmitter unit comprising, a multiplexer for accepting input signals and for receiving nonlinearity information in a reverse channel connected to said receiver unit, a predistorter for applying the nonlinearity information to the input signals, an interpreter for receiving the nonlinearity information from said receiver unit and providing it in useable form to said predistorter, and a transmitter for transmitting the input signals on a first frequency and for transmitting the nonlinearity information on a second frequency; and said receiver unit comprising, a receiver for receiving the input signals on the first frequency and for receiving the nonlinearity information on the second frequency, a demodulator with a processor for extracting the nonlinearity information from the received input signals, a controller unit for providing the nonlinearity information from said demodulator through said reverse channel to said multiplexer for transmission by said transmitter on the second frequency and to said interpreter for application in said predistorter.

Claim 27

Dependent Claim 186 words

A signal transmission system for predistorting a signal to compensate for nonlinearities in the communicated signal, the system comprising plural transmitter/receivers, each of which comprises a transmitter unit and a receiver unit: said transmitter unit comprising, a multiplexer for accepting input signals and for receiving nonlinearity information in a reverse channel connected to said receiver unit, a predistorter for applying the nonlinearity information to the input signals, an interpreter for receiving the nonlinearity information from said receiver unit and providing it in useable form to said predistorter, and a transmitter for transmitting the input signals on a first frequency and for transmitting the nonlinearity information on a second frequency; and said receiver unit comprising, a receiver for receiving the input signals on the first frequency and for receiving the nonlinearity information on the second frequency, a demodulator with a processor for extracting the nonlinearity information from the received input signals, a controller unit for providing the nonlinearity information from said demodulator through said reverse channel to said multiplexer for transmission by said transmitter on the second frequency and to said interpreter for application in said predistorter.

Claim 28

Dependent Claim 40 words

The system of claim 19 wherein said processor comprises a counter for counting occurrences of nonlinearities in the received input signals, and means for generating a nonlinearity correction, and wherein the nonlinearity information includes the count and the nonlinearity correction.

Claim 29

Independent Claim 136 words

A method of predistorting an RF signal to compensate for nonlinearities introduced when the RF signal is communicated, the method comprising the steps of: (a) transmitting an RF signal from a first transmitter/receiver to a second transmitter/receiver on a first frequency; (b) extracting nonlinearity data from the RF signal received at the second transmitter/receiver, said extracting performed in a receiver unit; (c) transmitting a further RF signal containing the nonlinearity data from the second transmitter/receiver to the first transmitter/receiver on a second frequency, said transmitting performed in a transmitter unit; (d) communicating the nonlinearity data from the receiver unit to the transmitter unit through a reverse channel connection between the receiver and transmitter units; and (e) predistorting RF signals to be transmitted from the first transmitter/receiver on the first frequency by using the received nonlinearity data.

Claim 30

Independent Claim 136 words

A method of predistorting an RF signal to compensate for nonlinearities introduced when the RF signal is communicated, the method comprising the steps of: (a) transmitting an RF signal from a first transmitter/receiver to a second transmitter/receiver on a first frequency; (b) extracting nonlinearity data from the RF signal received at the second transmitter/receiver, said extracting performed in a receiver unit; (c) transmitting a further RF signal containing the nonlinearity data from the second transmitter/receiver to the first transmitter/receiver on a second frequency, said transmitting performed in a transmitter unit; (d) communicating the nonlinearity data from the receiver unit to the transmitter unit through a reverse channel connection between the receiver and transmitter units; and (e) predistorting RF signals to be transmitted from the first transmitter/receiver on the first frequency by using the received nonlinearity data.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	2002-06-07	2002-12-07	2003-06-08	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2006-06-07	2006-12-07	2007-06-08	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2010-06-07	2010-12-07	2011-06-08	$7700.00	Window Closed / Lapsed

Adaptive predistortion using over-the-hop feedback

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