Ethernet to phase shift key converter

• US 6,556,581 B1
• Filed: 10/30/1998
• Issued: 04/29/2003
• Est. Priority Date: 10/30/1998
• Status: Expired due to Fees

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: He, Ming, Liu, Ce Richard
• Primary Examiner(s): CANGIALOSI, SALVATORE A
• Application Number:
  US09/183,773
• Time in Patent Office: 1,642 Days
• Field of Search: 370/419, 370/425, 370/349, 375/244, 375/219, 375/273, 375/355
• US Class Current: 370/419
• CPC Class Codes: H04L 25/20 Repeater circuits; Relay circuits
• CPC Class Codes: H04L 25/4904 using self-synchronising codes, e.g. split-phase codes
• CPC Class Codes: H04L 27/00 Modulated-carrier systems

Abstract

A device for seamlessly providing 10BASE-T compatible data communications over an ordinary single twisted-pair home phone line between multiple computers and/or peripherals is disclosed. Each component that is to communicate over a home phone line needs a 10BASE-T compatible network interface card (NIC) for interfacing with the device. A transmit/receive switch is used to switch the device between a transmit mode and a receive mode. When a signal is being transmitted from a component, a Manchester decoder converts the signals received from the NIC into a raw data stream. A differential converter converts the raw data signal received from the NIC to a differential signal. A modulator is used to modulate the signal to a RF signal using a PSK, QPSK, QAM, MCM or similar modulation schemes. A filter is used to limit the bandwidth of the modulated signal and a driver is used to amplify the signal to match the impedance of the phone line. When the device receives a signal over the phone line, the signal is filtered using a bandpass filter and then amplified. The signal is then demodulated using an appropriate demodulation scheme before being differentially encoded. A Manchester encoder encodes the received signal for compatible operation with a receiving NIC.

Claims

1. A network converter that comprises:

an encoder/decoder configured to convert an encoded transmit signal received from a network interface card into a decoded transmit signal, and further configured to convert a decoded receive signal into an encoded receive signal that, is provided to the network interface card;

a transmit-side differential converter configured to convert the decoded transmit signal into a differential transmit signal;

a phase modulator configured to convert the differential transmit signal into a modulated radio frequency signal;

a bandpass filter configured to convert the modulated radio frequency signal into a transmit signal that travels over a two wire medium;

an amplifier configured to convert a receive signal from the two wire medium into a filtered radio frequency receive signal;

a phase demodulator configured to convert the filtered radio frequency receive signal into a baseband receive signal; and

a receive-side differential converter configured to convert the baseband receive signal into the decoded receive signal provided to the encoder/decoder.

2. The network converter of claim 1, wherein the encoder/decoder is a Manchester encoder/decoder.

3. The network converter of claim 1, wherein the encoded transmit signal and the encoded receive signal comply with 10BASE-T Ethernet protocol.

4. The network converter of claim 3, wherein the transmit and receive signals are differential binary phase shift keyed (DBPSK) signals.

5. The network converter of claim 1, wherein the transmit and receive signals are differential quadrature phase shift keyed (DQPSK) signals.

6. The network converter of claim 1, wherein the two wire medium is a twisted wire pair.

7. A system for data communications, the system comprising:

two or more computing devices each having an associated network interface card;

a two wire medium; and

two or more network converters each coupled between the two wire medium and a respective one of the network interface cards, wherein each network converter is configured to communicate over the two wire medium using a differential phase shift key modulated signal.

8. The system of claim 7, wherein each network converter includes:

a transmit-side differential converter configured to convert a binary transmit signal into a differential transmit signal;

a phase modulator configured to convert the differential transmit signal into a modulated radio frequency signal; and

a bandpass filter configured to convert the modulated radio frequency signal into a transmit signal that travels over a two wire medium.

9. The system of claim 8, wherein the transmit-side differential converter produces the differential transmit signal by combining each bit of the binary transmit signal with a previous bit of the differential transmit signal.

10. The system of claim 8, wherein each network converter further includes:

an amplifier configured to convert a receive signal from the two wire medium into a filtered radio frequency receive signal;

a phase demodulator configured to convert the filtered radio frequency receive signal into a baseband receive signal; and

a receive-side differential converter configured to convert the baseband receive signal into a decoded receive signal.

11. The system of claim 10, wherein each network converter further includes:

an encoder/decoder configured to convert an encoded transmit signal received from a network interface card into said binary transmit signal, and further configured to convert said decoded receive signal into an encoded receive signal that is provided to the network interface card.

12. The system of claim 11, wherein the encoder/decoder is a Manchester encoder/decoder.

13. The system of claim 7, wherein each network converter is further configured to convert an Ethernet signal from the respective one of the network interface cards to a transmitted differential phase shift key modulated signal, and is further configured to convert a received differential phase shift key modulated signal to an Ethernet signal to the respective one of the network interface cards.

14. A method of establishing computer communication over a two wire medium, the method comprising:

receiving an encoded transmit signal from a network interface card;

decoding the encoded transmit signal to obtain a decoded transmit signal;

converting the decoded transmit signal into a differential transmit signal;

phase modulating a radio frequency signal in accordance with the differential transmit signal; and

coupling the phase modulated radio frequency signal to the two wire medium.

15. The method of claim 14, further comprising:

receiving a phase modulated radio frequency signal from the two wire medium;

demodulating the received phase modulated radio frequency signal to obtain a baseband signal;

processing the baseband signal with a differential converter to obtain a decoded receive signal;

encoding the decoded receive signal to obtain an encoded receive signal; and

providing the encoded receive signal to a network interface card.

16. The method of claim 14, wherein the encoded transmit signal is a 10BASE-T Ethernet signal.

17. The method of claim 14, wherein the two wire medium is a twisted wire pair.

18. The method of claim 14, wherein the phase modulated signal is one of a differential binary phase shift keyed signal and a differential quadrature phase shift keyed signal.

19. The method of claim 14, wherein said converting includes:

storing bits from the differential transmit signal in a delay element; and

combining bits from the delay element with bits from the decoded transmit signal to produce bits in the differential transmit signal, wherein said combining employs a logical XOR operation.