Universal modem for digital video, audio and data communications

• US 5,940,438 A
• Filed: 02/18/1997
• Issued: 08/17/1999
• Est. Priority Date: 02/18/1997
• Status: Expired due to Fees

• Current Assignee: Mitsubishi Electric Research Laboratories, Inc. (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Electric Information Technology Center America, Inc. (Mitsubishi Electric Corporation)
• Inventors: Nakayama, Hiroyuki, Mizutani, Yoshiki, Bao, Jay, Poon, Tommy C.
• Primary Examiner(s): Chin, Stephen
• Assistant Examiner(s): Maddox, Michael W.
• Application Number:
  US08/801,748
• Time in Patent Office: 910 Days
• Field of Search: 375/222, 375/223, 375/219, 375/220, 379/93.01, 379/93.09
• US Class Current: 375/222
• CPC Class Codes: H04L 27/0008 arrangements for allowing a transmitter or receiver to use more than one type of modulation negotiating modulation type for two-way transmission paths H04L5/1453

Abstract

A universal modem has a software-configurable modulator/demodulator which commodates different modulation formats such as those associated with terrestrial, cable, phone line, satellite and wireless communications to be transmitted and received through a single device in which the modem has reconfigurable logic to accommodate the format of the signals being received or transmitted. Note that the modulator or demodulator can be used separately or the two units can be combined and used for transceivers, with either the same software configuring both the modulator and demodulator, or with different software used for the two units. In the receive mode, the universal modem detects the modulation format of the incoming signal and reconfigures the logic of its software-configurable demodulator to output demodulated digital data for further processing. In the transmit mode, information to be transmitted is provided with the appropriate modulation format by setting a software-configurable modulator in the universal modem to the particular format. In one embodiment, in the receive mode the incoming signal is A-D converted, with a host processor utilized to detect the type of modulation associated with the incoming signal and through a configuration controller configures a random access memory which is coupled to the software-configurable demodulator. In advanced television applications, the demodulated signal is passed through an equalizer, a Trellis Decoder and Reed-Solomon Decoder to provide an appropriate filtered and level-adjusted digital signal that is coupled to the next processing stage.

Claims

1. A universal modem to accommodate different modulation formats for use in the modulation and demodulation of a signal, comprising:

a modulator and demodulator having software-configurable logic means for providing modulation and demodulation of a signal, said software configurable logic means including functional hardware blocks, each performing a predetermined function, and means for selectively interconnecting said hardware blocks;

means for generating, as an output, configuration instructions for said software-configurable logic means; and

,

means for coupling said output to said software configurable logic means to configure said modem for the modulation format specified by said configuration instructions by interconnecting said hardware blocks to correspond to said instructions.

2. A universal modem to accommodate different modulation formats for use in the modulation and demodulation of a signal comprising:

a modulator and demodulator, said demodulator having software-configurable logic means for providing demodulation of a signal having a predetermined modulation format, said software configurable logic means including functional hardware blocks, each performing a predetermined function, and means for selectively interconnecting said hardware blocks;

means for ascertaining the modulation type of said signal and for generating, as an output, configuration instructions for said software-configurable logic means; and

means for coupling said output to said software configurable logic means, thereby to configure said demodulator for said modulation format by interconnecting said hardware blocks to correspond to said instructions.

3. The modem of claim 2, wherein said software-configurable logic means includes a number of elements, each performing a different demodulation function, and means for interconnecting said elements to perform demodulation of said signal in accordance with said configuration instructions.

4. The modem of claim 3, wherein said elements are taken from the group consisting of arithmetic logic units, registers, fifo buffers, gates, finite impulse response filters and infinite impulse response filters.

5. The modem of claim 2, wherein said modulator includes said software-configurable logic means;

software for configuring said software-configurable logic means to modulate a signal with a predetermined modulation format based on the configuration specified by said software; and

,

means for running said software to configure said software-configurable logic means.

6. The modem of claim 2 wherein said demodulator includes a software-configurable equalizer and wherein said coupling means includes means for coupling said configuration instructions to said equalizer.

7. Apparatus to accommodate different modulation formats for use in the demodulation of a signal, comprising;

a demodulator having software-configurable logic means for providing demodulation of a signal having a predetermined modulation format, said software configurable logic means including functional hardware blocks, each performing a predetermined function, and means for selectively interconnecting said hardware blocks;

means for ascertaining the modulation format of said signal and for generating, as an output, configuration instructions for said software-configurable logic means; and

,

means for coupling said output to said software configurable logic means, thereby to configure said demodulator for said modulation format by interconnecting said hardware blocks to correspond to said instructions.

8. The apparatus of claim 7, wherein said software-configurable logic means includes a number of elements, each performing a different demodulation function, and means for interconnecting said elements to perform demodulation of said signal in accordance with said configuration instructions.

9. The apparatus of claim 8, wherein said elements are taken from the group consisting of arithmetic logic units, registers, fifo buffers, gates, finite impulse response filters and infinite impulse response filters.

10. Apparatus to accommodate different modulation formats for use in the modulation of a signal, comprising:

a modulator having software-configurable logic means for providing a modulation format for said signal based on the configuration of said logic means, said software configurable logic means including functional hardware blocks, each performing a predetermined function, and means for selectively interconnecting said hardware blocks;

means for setting the modulation format for said signal by generating as an output configuration instructions for said software-configurable logic means; and

,

means for coupling said output to said software configurable logic means, thereby to configure said modulator for the modulation format set by interconnecting said hardware blocks to correspond to said instructions.

11. The apparatus of claim 10, wherein said software-configurable logic means includes a number of elements, each performing a different modulation function, and means for interconnecting said elements to perform modulation of said signal in accordance with said configuration instructions.

12. The apparatus of claim 11, wherein said elements are taken from the group consisting of arithmetic logic units, registers, fifo buffers, gates, finite impulse response filters and infinite impulse response filters.

13. In a receiving device adapted to receive signals of different modulation formats, a demodulator having a software-configurable logic unit, said software configurable logic unit including functional hardware blocks, each performing a predetermined function, and means for selectively interconnecting said hardware blocks, said demodulator being coupled to the output of said receiver;

and a computer for configuring said software-configurable logic unit with configuration instructions such that said demodulator is set to demodulate a signal having a predetermined modulation format by interconnecting said hardware blocks to correspond to said instructions.

14. The receiving device of claim 13 wherein said receiving device has a channel selector and further including a channel detector having as an output the channel to which said channel selector is set, means for coupling the output of said channel detector to said computer and means within said computer for setting said predetermined modulation type to that expected for signals on the detected channel.

15. The receiving device of claim 13 and further including a flag on the signal received at said receiving device, said flag indicating modulation format, a flag detector having as an output the modulation format of said received signal, and means with said computer for setting said predetermined modulation type to that indicated by the output of said flag detector.

16. The receiving device of claim 13 and further including a smart card and a smart card reader, said smart card having a code specifying the modulation format of a signal to be received by said receiving device, said smart card reader having an output coupled to said computer containing said code and means within said computer for reading said code and setting said predetermined modulation type to that corresponding to said code.

17. In a receiving device adapted to receive signals of different modulation formats, a demodulator having a software-configurable logic unit, said demodulator being coupled to the output of said receiver;

and a computer for configuring said software-configurable logic unit such that said demodulator is set to demodulate a signal having a predetermined modulation format, said demodulator initially demodulating all expected modulation types and further including an error signal generator coupled to the output of said demodulator for generating an error signal, a detector for detecting for which modulation format said error signal is at a minimum after said demodulator demodulates all expected modulation formats and means within said computer for setting said predetermined modulation type to that modulation type having said minimum error signal.

18. Apparatus to accommodate different modulation formats for use in the demodulation of a signal received on an input, comprising:

a control signal;

a demodulator having software configurable logic including functional hardware blocks, each performing a predetermined function, and selective interconnection of said hardware blocks, said demodulator employing different demodulator formats in terms of the interconnection of said hardware blocks, said demodulator coupled to said input and providing demodulation of said signal having a predetermined format based on said control signal with said control signal specifying said interconnection;

a detector coupled to said input and generating as an output different instructions for different demodulation formats based on the detected demodulation format; and

,

a memory coupled between said demodulator and said detector for storing configuration data, said memory supplying said configuration data to said demodulator as said control signal to activate one of said different demodulation formats.