Multichannel predistortion linearizer for multiple amplifiers with multiple antennas
First Claim
1. A method for amplifying a plurality of baseband input signals using a plurality of amplifiers, the method comprising the steps of:
- modulating each one of a plurality of phase locked carrier signals with a corresponding one of said plurality of baseband input signals, each one of said phase locked carrier signals being at a different frequency;
dividing each of the input signals into components from which the original input signals can be reconstructed;
developing a specially constructed signal which is likewise divided into components wherein said specially constructed signal is generated as a function of (i) said baseband signals and (ii) information indicative of the frequencies and phases of said carrier signals;
supplying a component of each of the input signals and a component of the specially constructed signal to at least one of the amplifiers; and
constructing amplified versions of the input signals from the outputs of the amplifiers.
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Accused Products
Abstract
The peaking of multiple input signals applied to the inputs of two or more distinct amplifiers, and the resultant intermodulation, can be reduced, or avoided, by: a) dividing each of the input signals into components from which the original input signals can be reconstructed, e.g., by using a Butler matrix of order greater than 2×2; b) developing a specially constructed signal which is likewise divided into components; c)supplying a component of each of the input signals and a component of the specially constructed signal to at least one of the amplifiers; and d) constructing amplified versions of the original input signals from the outputs of the amplifiers, e.g., by using another identical Butler matrix. The specially constructed signal is generated so as to reduce: 1) peaking at the one of amplifiers whose input signal peaking results in the highest peak during a particular time period; and 2) intermodulation in the output signals. The input signals may each be a modulated carrier signal and each of the amplified versions of the original input signals is supplied to a different antenna for transmission. The specially constructed signal can range over the entire bandwidth of the signals being amplified while the amplified version of it may be discarded, e.g., not supplied to any antenna.
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Citations
42 Claims
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1. A method for amplifying a plurality of baseband input signals using a plurality of amplifiers, the method comprising the steps of:
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modulating each one of a plurality of phase locked carrier signals with a corresponding one of said plurality of baseband input signals, each one of said phase locked carrier signals being at a different frequency; dividing each of the input signals into components from which the original input signals can be reconstructed; developing a specially constructed signal which is likewise divided into components wherein said specially constructed signal is generated as a function of (i) said baseband signals and (ii) information indicative of the frequencies and phases of said carrier signals; supplying a component of each of the input signals and a component of the specially constructed signal to at least one of the amplifiers; and constructing amplified versions of the input signals from the outputs of the amplifiers. - View Dependent Claims (2, 3, 4, 5)
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6. Apparatus for amplifying a plurality of baseband input signals, comprising:
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a plurality of modulating means for modulating each one of a plurality of phase locked carrier signals by a corresponding one of said plurality of baseband signals and producing a plurality of modulated input signals, each of said phase locked carrier signals being at a different frequency; means for dividing each of the modulated input signals into components from which the original input signals can be reconstructed; means for developing a specially constructed signal which is likewise divided into components wherein said means for developing the specially constructed signal generates the specially constructed signal as a function of (i) said baseband signals and (ii) information indicative of the frequencies and phases of said carrier signals; a plurality of amplifiers, each for amplifying a component of each of the input signals and a component of the specially constructed signal; and means for constructing amplified versions of the input signals from the outputs of the amplifiers. - View Dependent Claims (7, 8, 9, 10)
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11. Apparatus for amplifying N input signals to produce N output signals, each of said N output signals being an amplified version of a respective one of said input signals, where N is greater than one, the apparatus comprising:
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a first Butler matrix having N+1 input ports and N+1 output ports, N of said input ports each receiving one of said N input signals; N+1 amplifiers, each having an input port and an output port, the input port of each of said amplifiers being coupled to a respective one of said N+1 output ports of said first Butler matrix; a second Butler matrix having N+1 input ports and N+1 output ports, each of said N+1 input ports of said second Butler matrix being coupled to the output port of a respective one of said amplifiers, N of said output ports of said second Butler network supplying said N output signals; and a peaking reduction signal generator which supplies a peaking reduction signal to said input port of said first Butler matrix that is not receiving one of said N input signals, said peaking reduction signal being generated as a function of said N input signals. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19)
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20. Apparatus for amplifying N input signals to produce N output signals corresponding to said N input signals, where N is an integer greater than one, each of said N output signals being an amplified version of a respective one of said N input signals, the apparatus comprising:
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means responsive to said N input signals for generating a peaking reduction signal; means responsive to said N input signals and to said peaking reduction signal for performing an involutory transform on said N input signals and said peaking reduction signal and for supplying as an output M output signals, where M is equal to or greater than N+1 and less than 2N, each of said M output signals containing a component of each of said N input signals and said peaking reduction signal; M means for amplifying, each being coupled to receive as an input a respective one of said M output signals supplied from said first involutory transform means and each for supplying as an output an amplified version of said M output signals; and means for performing an involutory transform on said amplified M output signals, and for supplying as an output amplified versions of said N input signals and an amplified version of said peaking reduction signal. - View Dependent Claims (21, 22, 23, 24, 25, 26, 27, 28)
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29. Apparatus for amplifying N input signals to produce N output signals, where N is greater than one, each of said N output signals corresponding to a respective one of said input signals, the apparatus comprising:
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a first Butler matrix having N+1 input ports and N+1 output ports, N of said input ports each receiving one of said input signals; N+1 amplifiers, each of said amplifiers being arranged to amplify a received version of a respective one of said N+1 signals supplied as an output from said first Butler matrix; a second Butler matrix having N+1 input ports and N+1 output ports, each of said N+1 input ports of said second Butler matrix receiving a respective one of said amplified versions of said signals supplied as outputs from said N+1 amplifiers, N of said output ports of said second Butler network supplying said N output signals; and a peaking reduction signal generator, said peaking reduction signal being (i) supplied to the input port of said first Butler matrix that is not receiving one of said N input signals, and (ii) being generated as a function of said N input signals to reduce the otherwise resulting intermodulation in said N output signals. - View Dependent Claims (30, 31, 32, 33, 34, 35, 36)
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37. Apparatus comprising:
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first and second Butler matrices having an order greater than 2×
2;a plurality of amplifiers; and a peaking reduction signal generator; wherein (i) said first Butler matrix receives as inputs a plurality of input signals for amplification and transmission as well as at least a peaking reduction signal supplied as an output from said peaking reduction signal generator, (ii) a version of each output of said first Butler matrix is amplified by a respective one of said plurality of amplifiers, and (iii) said second Butler matrix receives as an input the outputs of said amplifiers and supplies as an output at least amplified versions of said input signals for amplification and transmission. - View Dependent Claims (38, 39, 40, 41)
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42. Apparatus for amplifying N input signals to produce N output signals corresponding to said N input signals, where N is an integer greater than one, each of said N output signals being an amplified version of a respective one of said input signals, the apparatus comprising:
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means responsive to said N input signals for generating a peaking reduction signal; first means for performing an involutory transform on said N input signals and said peaking reduction signal and for supplying as an output N+1! M output signals, where M is equal to or greater than N+1 and less than 2N, and at least one of said N+1! M output signals containing a component of (i) at least one of said input signals and (ii) said peaking reduction signal; N+1! M means for amplifying, each being coupled to receive as an input a respective one of said N+1! M output signals supplied from said first involutory transform means and supplying as an output an amplified version of said N+1! M output signals; and second means for performing an involutory transform on said amplified N+1! M output signals, and for supplying as an output amplified versions of said N input signals and an amplified version of said peaking reduction signal.
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Specification