Home-appliance network with nodes identified by direct-sequence spreading codes

• US 6,218,931 B1
• Filed: 10/08/1999
• Issued: 04/17/2001
• Est. Priority Date: 10/08/1999
• Status: Expired due to Term

• Current Assignee: GlobalFoundries, Inc.
• Original Assignee: Advanced Micro Devices, Inc.
• Inventors: Tobias, David, Asghar, Saf
• Primary Examiner(s): POPE, DARYL C
• Application Number:
  US09/415,427
• Time in Patent Office: 557 Days
• Field of Search: 340/310.01, 340/310.02, 340/310.03, 340/310.04, 340/310.05, 340/310.06, 340/310.07
• US Class Current: 370/479
• CPC Class Codes: H04B 1/707 using direct sequence modulation
• CPC Class Codes: H04B 2203/5433 Remote metering
• CPC Class Codes: H04B 3/54 Systems for transmission via power distribution lines
• CPC Class Codes: H04L 12/2803 Home automation networks
• CPC Class Codes: H04L 12/282 based on user interaction within the home receiver circuitry for displaying additional information being controlled by a remote control apparatus H04N21/42204
• CPC Class Codes: H04L 12/2838 Distribution of signals within a home automation network, e.g. involving splitting/multiplexing signals to/from different paths adaptations of television systems for transmission by electric cable for domestic distribution H04N7/106; hybrid transport H04L12/6418; home network arrangements specially adapted for distribution of digital video signals H04N7/24
• CPC Class Codes: H04L 2012/2843 Mains power line
• CPC Class Codes: H04L 2012/285 Generic home appliances, e.g. refrigerators
• CPC Class Codes: H04L 27/02 Amplitude-modulated carrier systems, e.g. using on-off keying; Single sideband or vestigial sideband modulation H04L27/32 takes precedence
• CPC Class Codes: H04L 27/10 Frequency-modulated carrier systems, i.e. using frequency-shift keying H04L27/32 takes precedence
• CPC Class Codes: H04L 27/2071 in which the data are represented by the carrier phase, e.g. systems with differential coding

Abstract

Described herein is a network interface for coupling residential appliances into a code-division multiple access (CDMA) network. The network is used to convey appliance control signals and appliance status signals. The network interface includes a transmitter and/or a receiver, depending on the communications needs of the residential appliance. A spreading-code generator in the network interface generates a spreading code that identifies the residential appliance. A spreading mixer modulates a narrowband transmit signal with the spreading code, thereby generating a spread-spectrum transmit signal. The wideband transmit signal is then coupled into the physical medium of the network. In one embodiment, the physical medium is a residential wiring grid, and a wiring interface in the transmitter unit couples the spreading mixer with the residential wiring. Spread-spectrum signals received from the wiring grid are despread with an appropriate spreading code to extract the desired signal. Also described herein is a network interface for a wired network. The network interface includes a modulator configured to receive a stream of transmit data and to generate a modulated carrier signal from the data. The modulated carrier is spread by a direct-sequence spreading circuit, using a node-specific spreading code, into a wideband signal. The wideband signal is then coupled onto the wired network.

Claims

1. A network interface for a residential appliance, the network interface comprising:

a digital-to-analog converter (DAC) configured to receive a stream of transmit data and to generate a baseband signal therefrom;

wherein the transmit data include one or more of;

an appliance control signal and an appliance status signal;

a high-frequency oscillator configured to generate a carrier wave;

a high-frequency mixer coupled to said high-frequency oscillator and to said DAC, wherein said high-frequency mixer is configured to receive the carrier wave from said high-frequency oscillator and to modulate the baseband signal onto the carrier wave, thereby generating a narrowband transmit signal;

a spreading-code generator configured to generate a spreading code, wherein the spreading code identifies the residential appliance;

a spreading mixer coupled to said high-frequency mixer and to said spreading-code generator, wherein said spreading mixer is configured to receive the narrowband transmit signal from said high-frequency mixer, and to receive the spreading code from said spreading-code generator, wherein said spreading mixer is configured to modulate the narrowband transmit signal with the spreading code, thereby generating a wideband transmit signal;

a wiring interface coupled to said spreading mixer and configured to receive the wideband transmit signal therefrom;

wherein the wiring interface is adapted to transmit the wideband transmit signal onto a household power grid;

wherein the wiring interface is further adapted to receive a wideband received signal from the household power grid;

a despreading mixer coupled to said wiring interface and to said spreading-code generator, wherein said despreading mixer is configured to receive the wideband received signal from the wiring interface and to receive the spreading code from said spreading-code generator, wherein said despreading mixer is configured to demodulate the wideband received signal with the spreading code, thereby recovering a narrowband received signal;

a detector circuit coupled to said despreading mixer and configured to generate a digital signal in response to the narrowband received signal.

2. The network interface of claim 1, wherein the network interface is adapted for mounting in an electrical receptacle or in an electrical switch.

3. The network interface of claim 1, wherein the network interface is adapted for mounting in the residential appliance.

4. The network interface of claim 1, wherein the spreading code is a Walsh code or a maximal-length spreading sequence.

5. The network interface of claim 1, wherein the residential appliance is a data-processing system, a telephone device or a lighting unit, a cleaning appliance, a cooking appliance or a metering device.

6. The network interface of claim 1, wherein said DAC is a PSK modulator, an ASK modulator, or an FSK modulator.