A system and method for communicating information signals using spread spectrum communication techniques. PN sequences are constructed that provide orthogonality between the users so that mutual interference will be reduced, allowing higher capacity and better link performance. With orthogonal PN codes, the cross-correlation is zero over a predetermined time interval, resulting in no interference between the orthogonal codes, provided only that the code time frames are time aligned with each other. In an exemplary embodiment, signals are communicated between a cell-site and mobile units using direct sequence spread spectrum communication signals. In the cell-to-mobile link, pilot, sync, paging and voice channels are defined. Information communicated on the cell-to-mobile link channels are, in general, encoded, interleaved, bi-phase shift key (BPSK) modulated with orthogonal covering of each BPSK symbol along with quadrature phase shift key (QPSK) spreading of the covered symbols. In the mobile-to-cell link, access and voice channels are defined. Information communicated on the mobile-to-cell link channels are, in general, encoded, interleaved, orthogonal signaling along with QPSK spreading.

System and method for generating signal waveforms in a CDMA cellular telephone system

An automated meter reading server (15) having an open, distributed architecture that collects, loads, and manages system-wide data collected from energy meters (60) and routes the data automatically to upstream business systems. The automated meter reading server includes a repository (120) of metering data, and additionally provides timely access to information by including collection, storage, validation, estimation, editing, publishing and securing of meter consumption and interval data. The automated meter reading server obtains data from meters (60) equipped with modems via standard telephone lines or public RF networks. The data is converted from the format of the meter/communications infrastructure to a format usable by the automated meter reading server and the repository (120). The data is converted from the automated meter reading server compatible form to a format of a specific upstream business system prior to transmission.

Automated meter reading system

An electronic meter incorporates a TCP/IP protocol suite and an HTTP server to provide two-way access to the meter data. Alternatively, the TCP/IP protocol suite may be incorporated into a gateway serving multiple meters connected through a power line or wireless two-way network. The gateway may incorporate an HTTP server for accessing data from multiple meters and for transmission of data to individual meters. Other aspects of the disclosed system include the use of a common gateway interface for remote access to meter data and to set meter parameters using HTML forms in HTTP browsers; remote reading and setting of multiple meter parameters using a TCP/IP protocol suite; a TCP/IP protocol suite implemented in designated nodes in a CEBus LAN with remote access through TCP/IP to routers and brouters and to individual meters on the LAN; and an SLIP-PPP enabled gateway for remote TCP/IP access through a serial interface to a single or multiple meter parameters.

Remote access to electronic meters using a tcp/ip protocol suite

A system for determining a service outages and restorations that includes an outage management server (OMS) that generates reports outages and restoration information for metering endpoints. The outages may be caused by faults at various locations in the distribution network. The metering endpoint may include a transmitter having a battery backup that transmits the outage information upon a failure to detect a voltage at the endpoint. The transmission of the information may be filtered based on configurable criteria. The metering endpoints may also inform the OMS when power is restored. Thus, a utility may better service its customers by focusing manpower efforts using the outage and restoration information generated by the OMS.

Using a fixed network wireless data collection system to improve utility responsiveness to power outages

A novel and improved method and apparatus for high rate CDMA wireless communication is described. A set of individually gain adjusted subscriber channels are formed via the use of a set of orthogonal subchannel codes. The set of sub-channel codes are comprised of four Walsh codes. The pilot data and control data are combined onto one channel. The remaining two transmit channels are used for transmitting non-specified digital data including user data or signaling data, or both.

High data rate CDMA wireless communication system

A spread spectrum communications system includes an encoder for differentially encoding a spread spectrum spreading code sequence in accordance with an input data signal. Each chip of the spreading code sequence is inverted, or not inverted, relative to the polarity of a corresponding chip of the spreading code sequence a fixed time delay previously, depending on whether the input data is a logic one or zero, respectively. At the receiver, the data is recovered in a differential data decoder wherein the presently received chip of the spread spectrum signal and a corresponding previously received chip of spread spectrum signal, received a fixed time delay previously, are compared one chip at a time. Since it is the spreading code sequence that is differentially encoded and differentially decoded, there is no need for a synchronized code sequence generator at the receiver, and data synchronization is achieved after one cycle time of the received spread spectrum spreading code sequence has elapsed.

Differential correlator for spread spectrum communication system

A multiple phase PSK demodulator for use in a spread spectrum communication system includes a plurality of baseband frequency converters coupled to a corresponding plurality of differential decoders in order to directly recover the encoded PSK data. The logic outputs of the plurality of differential data decoders are coupled to a majority vote logic circuit for determining the correct logic level output signal of the plurality of differential data decoders. In another embodiment, a three phase resistive network is used to convert the two phase quadrature output of two baseband frequency converters to plural phase outputs coupled to the inputs of a corresponding plurality of differential data decoders.

Multiple phase PSK demodulator

A multiple phase PSK demodulator includes a plurality of baseband frequency converters coupled to a corresponding plurality of differential data decoders in order to directly recover the encoded PSK data. Means are provided for determining which of the differential data decoders have the correct output at any given time. The relative output strength of the baseband frequency converters can be compared and the output of the differential data decoder following the baseband frequency converter having the greater output signal strength is selected, or, a majority vote of the logic outputs of the plurality of differential data decoders is used to determine the output of the PSK demodulator.

Method and apparatus for the demodulation of binary psk signals

A spread spectrum communications system includes an encoder for differentially encoding a spread spectrum spreading code sequence in accordance with an input data signal. Each chip of the spreading code sequence is inverted, or not inverted, relative to the polarity of a corresponding chip of the spreading code sequence a fixed time delay previously, depending on whether the input data is a logic one or zero, respectively. At the receiver, the data is recovered in a differential data decoder wherein the presently received chip of the spread spectrum signal and a previously received chip of spread spectrum signal, a fixed time delay previously, are compared one chip at a time. Since it is the spreading code sequence that is differentially encoded and differentially decoded, there is no need for a synchronized code sequence generator at the receiver, and data synchronization is achieved after one cycle time of the received spread spectrum spreading code sequence has elapsed.

Peter Kendall Cripps

Papers

Differential correlator for spread spectrum communication system

Multiple phase PSK demodulator

Method and apparatus for the demodulation of binary psk signals

Spread spectrum communication system.