Dual mode transmitter and receiver

• US 5,291,516 A
• Filed: 09/18/1992
• Issued: 03/01/1994
• Est. Priority Date: 05/13/1991
• Status: Expired due to Term

• Current Assignee: Intel Corporation
• Original Assignee: Omnipoint Data Company, Incorporated
• Inventors: Dixon, Robert C., Vanderpool, Jeffrey S.
• Primary Examiner(s): CANGIALOSI, SALVATORE A
• Application Number:
  US07/948,293
• Time in Patent Office: 529 Days
• Field of Search: 375/1
• US Class Current: 375/131
• CPC Class Codes: H04B 1/005 adapting radio receivers, transmitters andtransceivers for operation on two or more bands, i.e. frequency ranges
• CPC Class Codes: H04B 1/0057 using diplexing or multiplexing filters for selecting the desired band
• CPC Class Codes: H04B 1/406 with more than one transmission mode, e.g. analog and digital modes
• CPC Class Codes: H04B 1/69 Spread spectrum techniques
• CPC Class Codes: H04B 1/707 using direct sequence modulation
• CPC Class Codes: H04B 7/2634 for channel frequency control
• CPC Class Codes: H04J 13/00 Code division multiplex systems for frequency hopping H04B1/713
• CPC Class Codes: H04J 13/0022 PN, e.g. Kronecker
• CPC Class Codes: H04J 13/10 Code generation
• CPC Class Codes: H04L 1/0001 Systems modifying transmission characteristics according to link quality, e.g. power backoff adaptive data allocation for multicarrier modulation H04L5/0044; controlling transmission power for radio systems H04W52/04
• CPC Class Codes: H04L 27/12 Modulator circuits; Transmitter circuits
• CPC Class Codes: H04W 84/042 Public Land Mobile systems, e.g. cellular systems
• CPC Class Codes: H04W 88/06 adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals

Abstract

A dual-mode transmitter having an antenna, a mode controller, a source encoder, a tunable-frequency synthesizer, a chip-code generator, a spread-spectrum modulator, a narrowband modualator, a power amplifier, and an adjustable bandpass filter. Also provided is a dual-mode receiver having a mode controller, a tunable-frequency synthesizer, a chip-code generator, an antenna, an adjustable bandpass filter, a preamplifier, a frequency converter, an IF amplifier, a spread-spectrum despreader, a spread-spectrum demodulator, a narrowband modulator, and a source decoder. For the transmitter and receiver, the mode controller selects receiving a narrowband modulation or a spread-spectrum modulation. The tunable-frequency synthesizer generates a local oscillator signal for the receiver, and a carrier signal for the transmitter. The chip-code generator generates a chip code signal for both the transmitter and the receiver. With a narrowband modulation setting of the mode controller, the transmitter and receiver have the adjustable bandpass filters adjusted to a narrowband width for telephone communications. With a spread-spectrum setting of the mode controller, the adjustable bandpass filters and the system are adjusted to transmit and receive a wide bandwidth for passing the spread-spectrum signal.

Claims

1. A dual-mode transmitter comprising:

an antenna;

a mode controller for selecting narrowband modulation and spread-spectrum modulation;

information means for processing an information signal;

a tunable-frequency synthesizer for generating a carrier signal;

a chip-code generator for generating a chip-code signal;

a spread-spectrum modulator coupled to said information means, said tunable-frequency synthesizer and said chip-code generator for spread-spectrum modulating the processed information signal with the chip-code signal and the carrier signal as a spread-spectrum signal;

a narrowband modulator coupled to said information means and said tunable-frequency synthesizer for modulating the processed information signal with narrowband modulation as a narrowband modulated signal;

a power amplifier coupled to said mode controller, said spread-spectrum modulator and said narrowband modulator, responsive to a narrowband modulation setting of said mode controller for amplifying the narrowband modulated signal, and responsive to a spread-spectrum setting of said mode controller for amplifying the spread-spectrum signal;

an adjustable bandpass filter coupled to said antenna, said power amplifier and said mode controller, responsive to a narrowband modulation setting of said mode controller for adjusting a bandwidth of said adjustable bandpass filter to a narrow bandwidth for passing the narrowband modulated signal, and responsive to a spread-spectrum setting of said mode controller for adjusting the bandwidth of said adjustable bandpass filter to a wide bandwidth for passing the spread-spectrum signal.

2. The dual-mode transmitter as set forth in claim 1 wherein said mode controller includes a mode switch for selecting the narrowband modulation and the spread-spectrum modulation.

3. The dual-mode transmitter as set forth in claim 1 wherein said narrowband modulator includes an FM modulator modulating the signal-processed information signal with FM modulation.

4. The dual-mode transmitter as set forth in claim 1 wherein said spread-spectrum modulator includes a time division multiplexed modulator.

5. The dual-mode transmitter as set forth in claim 1 wherein said narrowband modulator includes a time division multiplexed modulator.

6. A dual-mode receiver comprising:

a mode controller for selecting a narrowband modulation and a spread-spectrum modulation;

a tunable-frequency synthesizer for generating a local oscillator signal;

a chip-code generator for generating a chip-code signal;

an antenna;

an adjustable bandpass filter coupled to said antenna and said mode controller, responsive to a narrowband modulation setting of said mode controller for adjusting a bandwidth of said adjustable bandpass filter to a narrow bandwidth for passing the narrowband modulated signal, and responsive to a spread-spectrum setting of said mode controller for adjusting the bandwidth of said adjustable bandpass filter to a wide bandwidth for passing the spread-spectrum signal;

a preamplifier coupled to said adjustable bandpass filter and said mode controller, responsive to a narrowband modulation setting of said mode controller for amplifying the filtered narrowband modulated signal, and responsive to a spread-spectrum setting of said mode controller for amplifying the filtered spread-spectrum signal;

a frequency converter coupled to said preamplifier and said tunable-frequency synthesizer, for converting, using the local oscillator signal, the filtered narrowband modulated signal and the filtered spread-spectrum signal to an IF signal;

an IF amplifier coupled to said frequency converter for amplifying the IF signal;

a spread-spectrum despreader coupled to said chip-code generator and through said mode controller to said IF amplifier, responsive to said mode controller selecting the spread-spectrum modulation, for spread-spectrum despreading, using the chip-code signal, the IF signal as a modulated signal;

a spread-spectrum demodulator coupled to said spread-spectrum despreader for demodulating the modulated signal as a demodulated signal;

a narrowband modulator coupled to said chip-code generator and through said mode controller to said IF amplifier, responsive to said mode controller selecting the narrowband modulation for demodulating the filtered narrowband modulated signal as a demodulated signal; and

information means coupled to said narrowband demodulator and to said spread-spectrum demodulator for signal processing the demodulated signal as an information signal.

7. The dual-mode receiver as set forth in claim 6 wherein said spread-spectrum despreader includes a surface-acoustic-wave device for despreading the IF signal.

8. The dual-mode receiver as set forth in claim 6 wherein said spread-spectrum demodulator includes an envelope detector for demodulating the modulated signal as a demodulated signal.