Simultaneous demodulation and decoding of a digitally modulated radio signal using known symbols
September 30, 2014. 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 ReferencesInterleavers for digital communications Log-polar signal processing Technique for improving the operation of decision feedback equalizers in communications systems utilizing error correction Direct phase digitization Method and apparatus for communicating interleaved data Identification of encoder type through observation of data received Multidimensional trellis-coded modulation for fading channels Adaptive maximum likelihood demodulator Method and apparatus for bidirectional demodulation of digitally modulated signals Speech decoding in a zero BER environment InventorApplicationNo. 305787 filed on 09/14/1994US Classes:375/262, Maximum likelihood decoder or viterbi decoder329/304, PHASE SHIFT KEYING OR QUADRATURE AMPLITUDE DEMODULATOR375/281, Quaternary375/331, More than two phases375/341Maximum likelihood decoder or viterbi decoderExaminersPrimary: Chin, WellingtonAssistant: Luther, William Attorney, Agent or FirmForeign Patent References
International ClassesH04L 027/00H03D 001/00 H04Q 001/20 AbstractSystems and methods according to the present invention provide a combination of demodulation and decoding, termed decodulation herein. By using knowledge of known symbols, decoding known symbols first, and then using the information obtained by decoding known symbols to decode unknown symbols, improved performance can be achieved. This technique can also be used to alleviate the conventional 3dB loss suffered systems using differentially coding and modulation as compared to coherent detection systems.Other References
Field of SearchSYSTEMS USING ALTERNATING OR PULSATING CURRENTParticular pulse demodulator or detector Phase shift keying Maximum likelihood decoder or viterbi decoder Locating predetermined portion of pulse Phase shift keying Quadrature amplitude modulation Maximum likelihood decoder or viterbi decoder Trellis encoder or Trellis decoder Quaternary Differential phase shift keying (diphase) Differential (diphase) More than two phases Plural phase (>2) Diversity PHASE SHIFT KEYING OR QUADRATURE AMPLITUDE DEMODULATOR Including logic element (e.g., logic gate or flip-flop) | |
