Method and apparatus for implementing carrierless amplitude/phase encoding in a network
September 22, 2015. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent ReferencesData transmission/reception network system Method and apparatus for wideband transmission of digital signals between, for example, a telephone central office and customer premises Multibit amplitude and phase modulation transceiver for LAN Fractional-division synthesizer for a voice/data communications systems Hub privacy filter for active star CSMA/CD network Synchronization scheme for a digital communications system Communication mode identification technique Patent #: 5444712 InventorApplicationNo. 324171 filed on 10/14/1994US Classes:375/219, TRANSCEIVERS375/298, Quadrature amplitude modulation375/340, Particular pulse demodulator or detector375/345, Automatic gain control375/355Synchronizing the sampling time of digital dataExaminersPrimary: Bocure, TesfaldetAttorney, Agent or FirmInternational ClassH04L 005/16AbstractA method and apparatus for (1) transmitting large amounts of data between a least a first and second station over a single twisted pair, (2) reducing cross talk in a network using carrierless amplitude modulation and phase modulation encoding (CAP) with independent data clock source at each station, (3) providing a relatively simple and fast data detection apparatus, (4) maintaining synchronization between stations during idle periods while minimizing cross talk, (5) providing a technique to allow filters to be trained during idle periods, and (6) providing a technique which allows automatic gain control to be used with CAP. Particular signalling symbols are associated with each of the following conditions: (1) idle state, (2) preamble, (3) start of frame detection, (4) test condition, (5) each possible combination of five binary bits representing 32 different data symbols, and (6) jam condition. For example, a unique pair of the four inner most points on the CAP 36 constellation are used for indicating idle mode. All four inner most points are used for testing the link and training the filters in the receiver.Field of SearchTRANSCEIVERSModems (data sets) Quadrature amplitude modulation Quadrature amplitude modulation RECEIVERS TRANSMITTERS Particular pulse demodulator or detector Automatic gain control Phase displacement, slip or jitter correction Phase locked loop Start - stop Training period or initial set up Synchronizing the sampling time of digital data Feedback, receiver to transmitter Echo suppression or cancellation Having residual echo cancellation or suppression Transformer or resonant circuit in interstage coupling (e.g., stagger tuning) Gain control Automatic Having feedback | |
