Wired and cordless telephone systems with extended frequency range

• US 6,556,965 B1
• Filed: 03/24/1999
• Issued: 04/29/2003
• Est. Priority Date: 03/24/1999
• Status: Expired due to Term

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Legerity Incorporated (Microsemi Semiconductor Corp.)
• Inventors: Teich, Paul R., Borland, David J.
• Primary Examiner(s): {haeck over (S)}mits, T{overscore (a)}livaldis Ivars
• Application Number:
  US09/275,173
• Time in Patent Office: 1,497 Days
• Field of Search: 704/200.1, 704/500, 455/426
• US Class Current: 704/200.1
• CPC Class Codes: G10L 19/02 using spectral analysis, e.g. transform vocoders or subband vocoders
• CPC Class Codes: H04B 10/116 Visible light communication
• CPC Class Codes: H04M 1/253 Telephone sets using digital voice transmission
• CPC Class Codes: H04M 1/72502 with one base station connected to a single line
• CPC Class Codes: H04M 1/737 Characterised by transmission of electromagnetic waves other than radio waves, e.g. infrared waves

Abstract

A telephone that communicates high-quality audio signals and a method for communicating an audio signal with an extended frequency range over a telephone network. The cordless telephone has a handset unit with a sampler circuit, a compression circuit, decompression circuit, as well as analog-to-digital (A/D) and digital-to-analog (D/A) converters, which handset is coupled by an infrared (IR) wireless link to a base unit connected to the Public Switched Telephone Network (PSTN). In one embodiment, the telephone includes a sampler, a compression block, a telephone port, a decompression block, and a digital-to-analog (D/A) converter. The sampler receives a analog audio signal and digitizes the signal into a high-quality (705.6 kbps) digital audio signal. The compression block then encodes the digital audio signal into a compressed digital signal at a lower bit rate (such as 150 kbps or 56 kbps) with a compression algorithm such as MP3. The compressed digital signal is communicated through the telephone port to a telephone network. An incoming compressed digital signal is received from the telephone network by the telephone port and provided to the decompression block. From the received compressed digital signal, the decompression block reconstructs a digital audio signal at the high data rate. The D/A converter generates a reconstructed analog audio signal in response to the reconstructed digital audio signal.

Claims

1. A telephone for high-quality audio signals, the telephone comprising:

a sampler circuit configured to receive an analog audio signal and to digitize the analog audio signal, thereby generating a digital audio signal at a first data rate, and wherein the sampler circuit samples the analog audio signal at a rate of at least 44 kHz;

a compression circuit coupled to said sampler circuit wherein said compression circuit generates a compressed digital signal at a second data rate less than or equal to the first data rate in response to the digital audio signal;

a telephone port coupled to said compression circuit and configured to provide the compressed digital signal to a telephone line;

a decompression circuit coupled to said telephone port;

wherein said decompression circuit is configured to receive a received compressed digital signal through said telephone port from the telephone line, and wherein said decompression circuit is configured to generate a reconstructed digital audio signal at the first data rate in response to the received compressed digital signal; and

a digital-to-analog (D/A) converter coupled to said decompression circuit and configured to generate a reconstructed analog audio signal in response to the reconstructed digital audio signal;

wherein said sampler circuit, said compression circuit, said decompression circuit, and said D/A converter are comprised in a handset unit and wherein said telephone port is comprised in a base unit and wherein the handset unit and the base unit are coupled by a wireless link, wherein the wireless link is an infared (IR) link.

2. The telephone of claim 1, wherein the telephone is comprised in a personal computer.

3. The telephone of claim 1, wherein the telephone is comprised in an electronic appliance configured for remote access.

4. The telephone of claim 1, further comprising:

a microphone coupled to said sampler circuit and responsive to acoustic signals throughout an audible frequency range, wherein said microphone is configured to generate the analog audio signal in response to sounds incident on said microphone;

a speaker coupled to said D/A converter and capable of generating acoustic signals throughout the audible frequency range, wherein said speaker is configured to generate received sounds in response to the reconstructed analog audio signal.

5. The telephone of claim 4, wherein the audible frequency range is 20 Hz-20 kHz, and wherein said microphone and speaker have frequency responses over the audible frequency range.

6. The telephone of claim 1, wherein said sampler circuit is a PCM coder and wherein said D/A converter is a PCM decoder.

7. The telephone of claim 1, further comprising:

an audio port coupled to said sampler circuit and to said D/A converter,

wherein said audio port is configured to receive the analog audio signal from an external audio source, and to provide the analog audio signal to said sampler circuit; and

wherein said audio port is configured to receive the reconstructed analog audio signal from said D/A converter and to provide the reconstructed analog audio signal to an external audio device.

8. The telephone of claim 7, wherein said audio port is configured to provide the reconstructed analog audio signal to one or more of:

an external speaker, an external audio player, and an external audio recorder.

9. The telephone of claim 1, wherein said handset unit further comprises:

a microphone coupled to said sampler circuit and responsive to acoustic signals throughout an audible frequency range, wherein said microphone is configured to generate the analog audio signal in response to sounds incident on said microphone;

a speaker coupled to said D/A converter and capable of generating acoustic signals throughout the audible frequency range, wherein said speaker is configured to generate received sounds in response to the reconstructed analog audio signal;

a line coder coupled to said compression circuit and configured to generate an uplink baseband signal carrying the compressed digital signal;

a transmitter coupled to said line coder and configured to modulate an uplink carrier with the uplink baseband signal and to transmit the modulated uplink carrier to said base unit;

a receiver configured to receive a modulated downlink carrier from said base unit and to demodulate the modulated downlink carrier into a downlink baseband signal, wherein the received compressed digital signal is encoded onto the modulated downlink carrier; and

a line receiver coupled to said receiver and to said decompression circuit, wherein said line receiver is configured to recover the received compressed digital signal from the downlink baseband signal and to provide the received compressed digital signal to said decompression circuit.

10. The telephone of claim 1, wherein said base unit further comprises:

a line coder coupled to said telephone port and configured to receive the received compressed digital signal therefrom, wherein said line coder is configured to generate a downlink baseband signal carrying the received compressed digital signal;

a transmitter coupled to said line coder and configured to modulate a downlink carrier with the downlink baseband signal and to transmit the modulated downlink carrier to said handset unit;

a receiver configured to receive a modulated uplink carrier from said handset unit, wherein said modulated uplink carrier is encoded with the compressed digital signal, wherein the receiver is configured to demodulate the modulated uplink carrier into an uplink baseband signal; and

a line receiver coupled to said receiver and to said telephone port, wherein said line receiver is configured to recover the compressed digital signal from the uplink baseband signal and to provide the compressed digital signal to said telephone port.

11. The telephone of claim 1, wherein said compression circuit is an MPEG audio encoder and wherein said decompression circuit is an MPEG audio decoder.

12. The telephone of claim 1, wherein said compression circuit is an MP3 audio encoder and wherein said decompression circuit is an MP3 audio decoder.

13. The telephone of claim 1, wherein the first data rate is 705.6 kbps and wherein the second data rate is less than 170 kbps.