Method and apparatus for improving transmission of data in a wireless network

• US 6,038,430 A
• Filed: 12/10/1997
• Issued: 03/14/2000
• Est. Priority Date: 12/10/1997
• Status: Expired due to Term

• Current Assignee: Hewlett Packard Enterprise Development LP (Hewlett-Packard Enterprise Company)
• Original Assignee: 3Com Corporation (HP Inc.)
• Inventors: Buxton, Bert, Thomson, Larry Steve, Alelyunas, Carl
• Primary Examiner(s): Chin, Wellington
• Assistant Examiner(s): Jackson, Blane J.
• Application Number:
  US08/987,982
• Time in Patent Office: 825 Days
• Field of Search: 375/222, 375/249, 333/14, 455/72, 455/575, 455/422, 455/557, 455/63, 455/43
• US Class Current: 455/72
• CPC Class Codes: H04B 1/64 Volume compression or expansion arrangements
• CPC Class Codes: H04L 27/00 Modulated-carrier systems

Abstract

A method and apparatus are provided that improve data transmissions in a wireless network, optimized for the transmissions of voice signals, by companding data signals electrically about a spectral shaping module in data handling devices, preferably modems, at both the transmitting and receiving ends of the wireless network. At the transmitting end, the companding is performed by a compressor, electrically preceding a data de-emphasis module, and an expander, electrically succeeding the data de-emphasis module. At the receiving end, the companding is performed by a compressor, electrically preceding a data pre-emphasis module, and an expander, electrically succeeding the data pre-emphasis module. At both ends of the wireless network, companding better serves to facilitate the transmission of data across the wireless network because complimentary functions are performed symmetrically at both ends and because data streams are more complimentarily coupled to, and from, wireless transceivers that similarly perform companding electrically about voice and data streams between the transmitting and receiving ends. Such wireless transceivers being spectrally optimized for voice signal transmissions wherein spectral advantages occurring for voice signals causes spectral disadvantages for data signals within the same transceiver.

Claims

1. A data handling device for improving transmission of data in a wireless network, comprising:

a spectral shaping module for selectively spectrally shaping amplitude levels for a spectrally defined data stream across a frequency spectrum having low and high frequencies associated therewith;

a compressor module electrically preceding said spectral shaping module for compressing said data stream; and

an expander module electrically succeeding said spectral shaping module for electrically reversing the compression performed by said compressor module so that, in operation, said data stream is sequentially processed through said compressor, said spectral shaping and said expander modules in preparation for said data stream to be electrically coupled to a wireless transceiver of said wireless network.

2. The data handling device according to claim 1, wherein said spectral shaping module selectively alters said amplitude levels of said data stream by one of hardware implementation and software implementation means.

3. The data handling device according to claim 2, wherein said data handling device is capable of both transmitting and receiving, said spectral shaping module selectively alters said amplitude levels of said data stream by one of reducing and increasing said amplitude levels of said high frequencies with respect to said low frequencies depending upon whether said spectrally defined data stream is one of being transmitted and received, respectively, across said wireless network.

4. The data handling device according to claim 3, wherein said spectral shaping module selectively alters said amplitude levels of said data stream in order to spectrally approximate said data stream as a voice stream.

5. The data handling device according to claim 4, wherein said spectral shaping module selectively alters said amplitude levels of said data stream by increasing said amplitude levels of said high frequencies with respect to said low frequencies in order to spectrally return said data stream from being spectrally approximated as said voice stream to having substantially uniform amplitude levels across said frequency spectrum.

6. The data handling device according to claim 3, further comprising means for electrically coupling said data stream to said external data communication device.

7. The data handling device according to claim 1, wherein said data handling device is a modem.

8. The data handling device according to claim 1, wherein said spectral shaping module is one of a data de-emphasis module and a data pre-emphasis module.

9. The data handling device according to claim 1, wherein said data stream is sequentially processed, in operation, through said compressor, said spectral shaping and said expander modules as one of:

at a transmitting end in said wireless network as one of electrically preceding and succeeding a modulator; and

at a receiving end in said wireless network as one of electrically preceding and succeeding a de-modulator.

10. A modem for improving transmission of data in a wireless network, comprising:

a data de-emphasis module for spectrally shaping a first data stream into a first signal having spectral amplitudes at higher frequencies lower than spectral amplitudes at lower frequencies and a data pre-emphasis module for spectrally shaping a second signal having spectral amplitudes at said higher frequencies higher than spectral amplitudes at said lower frequencies into a second data stream;

a first data compressor module electrically preceding said data de-emphasis module for compressing first input data stream and a second data compressor module electrically preceding said data pre-emphasis module for electrically compressing a second input signal; and

a first data expander module electrically succeeding said data de-emphasis module for reversing said compression performed by said first data compressor module in preparation for said first signal to be electrically coupled to a wireless transceiver and a second data expander module electrically succeeding said data pre-emphasis module for reversing said compression performed by said second data compressor module in preparation for said second data stream to be electrically coupled to an external data communication device.

11. The modem according to claim 10, further comprising one of:

(i) a modulator operably coupled with said first data compressor module for modulating said first input data stream; and

(ii) a de-modulator operably coupled with said second data expander module for demodulating data as received from said second data expander module.

12. A system for improving transmission of data in a wireless communication network, comprising:

a wireless transceiver having

(a) a spectral shaping module for selectively spectrally shaping amplitude levels for spectrally defined voice and data streams across a frequency spectrum having low and high frequencies associated therewith; and

(b) a compressor module electrically preceding said spectral shaping module for electrically compressing said voice and data streams; and

a wireless transceiver modem having

(a) a data spectral shaping module for selectively altering amplitude levels of said data stream across said frequency spectrum; and

(b) a data compander module arranged electrically about said data spectral shaping module for sequentially compressing said data stream and for electrically reversing the compression thereof.

13. The system according to claim 12, further comprising electrical coupling means between said wireless transceiver modem and said wireless transceiver.

14. The system according to claim 12, wherein said wireless transceiver further comprises an expander module for electrically reversing the electrical compression performed by said compressor module in preparation for said data stream to be electrically coupled to an external data communication device.

15. The system according to claim 14, wherein said external data communication device is said wireless transceiver modem.

16. In a wireless communication network, a method for improving transmission of data, the steps comprising:

(a) spectrally shaping a spectrally defined data stream in a data spectral shaping module across a frequency spectrum having low and high frequencies associated therewith by selectively altering amplitude levels of said data stream at selected frequencies across said frequency spectrum;

(b) electrically companding said data stream about said spectral shaping module in both a data compressor module and a data expander module, said data compressor module electrically preceding said data spectral shaping module, said data expanding module electrically succeeding said data spectral shaping module; and

(c) modulating said data stream, the step of modulating said data stream being electrically one of preceding and succeeding said step of spectrally shaping said data stream.

17. The method according to claim 16, further comprising the step of coupling said data stream to a wireless transceiver having:

(a) a spectral shaping module for spectrally shaping said data stream and a spectrally defined voice signal across said frequency spectrum by selectively altering amplitude levels of said voice signal and said data stream at selected frequencies across said frequency spectrum; and

(b) a compander module electrically preceding said spectral shaping module for one of electrically compressing said voice signal and said data stream and electrically expanding said voice signal and said data stream.

18. The method according to claim 17, further comprising the step of transceiving said voice signal and said data stream across a communication channel.

19. The method according to claim 16, wherein the step of spectrally shaping said data stream further comprises one of the following steps:

(a) reducing said amplitude levels of said data stream at said high frequencies relative to said low frequencies to approximate a spectrally defined voice stream; and

(b) increasing said amplitude levels of said data stream at said high frequencies relative to said high frequencies to produce substantially uniform amplitude levels of said data stream across said frequency spectrum.