US5289464A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Frequency-multiplexed cellular telephone cell site base station and method of operating the same
Assignee: Nokia Bell Labs
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Filing: 1992-09-21
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Granted: 1994-02-22
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Expires: 2012-09-21
Abstract
Abstract The present invention is directed to a cellular telephone cell site base station (10) having a single radio transmitter (40) and radio receiver (14) for transmitting and receiving, respectively, multiplexed frequency-modulated (FM) signals. A filter bank synthesizer (36), associated with the transmitter, multiplexes individual signals for transmission by the transmitter by exponentially modulating the signals to higher frequency bands followed by low-pass filtering and interpolation using discrete Fourier transform techniques. A filter bank analyzer (18), associated with the receiver, demultiplexes multiplexed FM signals received by the receiver by exponentially modulating each signal to its original spectral position followed by low-pass filtering and decimation, using discrete Fourier transform techniques.
Inventors
- 👤 Robert C. Wang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 20:43
CPC Classifications
H; H04; H04L; H04L5/00; H04L5/02; H04L5/06; H04B; H04B7/00; H04B7/24; H04B7/26; H04B7/2621
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
216 words
A radio transceiver system comprising: a receiver for receiving a frequency-multiplexed signal containing K individual channels, where K is a positive integer, and for generating output signals indicative of the received signal; first signal-processing means for processing the output signals of the receiver to separate each of the K channels in the originally-received frequency-multiplexed signal; a plurality of K demodulators, each demodulating a separate one of the K channels separated by the first signal-processing means; a first plurality of K data and speech-processing circuits, each serving to process the demodulated channel produced by a separate demodulator in accordance with the manner in which the channel was demodulated to yield a separate one of K incoming voice/data signals; a second plurality of K data and speech-processing circuits, each processing a separate one of K outgoing voice/data signals in a predetermined manner; a plurality of K modulators, each modulating a separate one of the K outgoing voice/data signals in a particular manner in accordance with the way in which such signals were processed by a corresponding one of the second speech and data circuits; second signal-processing means for multiplexing the output signals of the K modulators to yield a frequency-multiplexed signal having K channels; and a transmitter for transmitting the frequency-multiplexed signal generated by the second signal-processing means.
Claim 2
Dependent Claim
216 words
A radio transceiver system comprising: a receiver for receiving a frequency-multiplexed signal containing K individual channels, where K is a positive integer, and for generating output signals indicative of the received signal; first signal-processing means for processing the output signals of the receiver to separate each of the K channels in the originally-received frequency-multiplexed signal; a plurality of K demodulators, each demodulating a separate one of the K channels separated by the first signal-processing means; a first plurality of K data and speech-processing circuits, each serving to process the demodulated channel produced by a separate demodulator in accordance with the manner in which the channel was demodulated to yield a separate one of K incoming voice/data signals; a second plurality of K data and speech-processing circuits, each processing a separate one of K outgoing voice/data signals in a predetermined manner; a plurality of K modulators, each modulating a separate one of the K outgoing voice/data signals in a particular manner in accordance with the way in which such signals were processed by a corresponding one of the second speech and data circuits; second signal-processing means for multiplexing the output signals of the K modulators to yield a frequency-multiplexed signal having K channels; and a transmitter for transmitting the frequency-multiplexed signal generated by the second signal-processing means.
Claim 3
Dependent Claim
56 words
The apparatus according to claim 1 wherein the first signal processing means comprises: analog-to-digital conversion means for converting the receiver output signals to digital signals; and filter bank analyzer means for (1) exponentially modulating, (2) low-pass filtering, and (3) decimating the digitized receiver output signals to demultiplex the originally received signal to yield K separate channels.
Claim 4
Dependent Claim
13 words
The apparatus according to claim 1 wherein each demodulator is an FM demodulator.
Claim 5
Dependent Claim
42 words
The apparatus according to claim 3 wherein each first data and data processing circuit comprises a digital signal processor programmed to processes the output signal of each demodulator by (1) high-pass filtering, (2) decimation with low-pass filtering, (3) expansion, and (4) de-emphasis.
Claim 6
Dependent Claim
13 words
The apparatus according to claim 1 wherein each demodulator comprises a TDMA demodulator.
Claim 7
Dependent Claim
33 words
The apparatus according to claim 3 wherein each first data and speech-processing circuit comprises a digital signal processor programmed to speech decode and then channel decode the output signal of a corresponding demodulator.
Claim 8
Dependent Claim
77 words
The apparatus according to claim 1 wherein the second signal-processing means comprises: filter bank synthesizer means for frequency-multiplexing the K modulator output signals by (1) separately interpolating each signal, (2) low-pass filtering each signal, (3) exponentially modulating each low-pass signal to a higher frequency band, and (4) summing the individually exponentially modulated signals to obtain a complex K channel frequency-multiplex signal; and digital-to-analog conversion means for converting the filter bank synthesizer output signal to an analog signal.
Claim 9
Dependent Claim
13 words
The apparatus according to claim 1 wherein each modulator is an FM modulator.
Claim 10
Dependent Claim
49 words
The apparatus according to claim 8 wherein each second data and speech-processing circuit comprises a digital signal processor programmed to process a signal for input to the modulator by: (1) high-pass filtering, (2) compression, (3) pre-emphasis, (4) limiting the signal, and (5) interpolating and low pass filtering the signal.
Claim 11
Dependent Claim
17 words
The apparatus according to claim 1 wherein each modulator serves to TDMA modulate the signal supplied thereto.
Claim 12
Dependent Claim
32 words
The apparatus according to claim 10 wherein each second data and speech-processing circuit comprises a digital signal processor for speech coding and channel coding a signal for input to a corresponding modulator.
Claim 13
Independent Claim
119 words
A method for processing an incoming modulated, frequency-multiplexed K-channel signal, where K is a positive integer, containing K voice and/or data signal portions to separate the K signal portions into discrete signals comprising the steps of: receiving the incoming K-channel signal and generating a pair of signals indicative of the in-phase and quadrature phase components thereof; converting each of the signals to digitized signals; exponentially modulating each of the digitized signals to yield K separate discrete signals; low-pass filtering each of the K discrete signals; decimating each of the K discrete signals; demodulating each of the K discrete signals; and processing each of the K discrete signals in accordance with the manner in which the signal portions were demodulated.
Claim 14
Independent Claim
119 words
A method for processing an incoming modulated, frequency-multiplexed K-channel signal, where K is a positive integer, containing K voice and/or data signal portions to separate the K signal portions into discrete signals comprising the steps of: receiving the incoming K-channel signal and generating a pair of signals indicative of the in-phase and quadrature phase components thereof; converting each of the signals to digitized signals; exponentially modulating each of the digitized signals to yield K separate discrete signals; low-pass filtering each of the K discrete signals; decimating each of the K discrete signals; demodulating each of the K discrete signals; and processing each of the K discrete signals in accordance with the manner in which the signal portions were demodulated.
Claim 15
Dependent Claim
15 words
The method according to claim 12 wherein each of the K discrete signals is frequency-demodulated.
Claim 16
Dependent Claim
16 words
The method according to claim 12 wherein each of the K discrete signals is TDMA demodulated.
Claim 17
Independent Claim
87 words
A method for combining K outgoing voice and/or data signals to yield a modulated, frequency-multiplexed, K-channel signal, where K is a positive integer, comprising the steps of: processing each of the K incoming signals in accordance with how such signals are to be subsequently modulated; modulating each of the processed K incoming signals; interpolating each of the modulated K incoming signals; low-pass filtering each of the K interpolated signals; complex-modulating each of the K low-pass-filtered signals; and summing the complex-modulated signals to yield the frequency-multiplexed K-channel signal.
Claim 18
Independent Claim
87 words
A method for combining K outgoing voice and/or data signals to yield a modulated, frequency-multiplexed, K-channel signal, where K is a positive integer, comprising the steps of: processing each of the K incoming signals in accordance with how such signals are to be subsequently modulated; modulating each of the processed K incoming signals; interpolating each of the modulated K incoming signals; low-pass filtering each of the K interpolated signals; complex-modulating each of the K low-pass-filtered signals; and summing the complex-modulated signals to yield the frequency-multiplexed K-channel signal.
Claim 19
Dependent Claim
16 words
The method according to claim 15 wherein each of the K incoming signals is frequency modulated.
Claim 20
Dependent Claim
15 words
The method according to claim 15 wherein each of the incoming signals is TDMA modulated.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-02-21 | 1997-08-23 | 1998-02-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-02-21 | 2001-08-23 | 2002-02-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-02-21 | 2005-08-23 | 2006-02-22 | $7700.00 | Window Closed / Lapsed |