Feedback residue compression for digital speech systems
Patent 3973081 Issued on August 3, 1976. Estimated Expiration Date: 
August 3, 1993. 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.
August 3, 1993. 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 References 3500441 3609551 3631520 3769612 InventorApplicationNo. 612992 filed on 09/12/1975US Classes:704/230, Quantization333/14, AMPLITUDE COMPRESSION AND EXPANSION SYSTEMS (I.E., COMPANDERS)375/240, BANDWIDTH REDUCTION OR EXPANSION375/249, Compand (overload prevention)704/219Linear predictionExaminersPrimary: Claffy, Kathleen H.Assistant: Kemeny, E. Matt Attorney, Agent or FirmAbstractA digital speech compression system uses a predictive feedback loop. The digital speech signals are compressed within the feedback loop for reducing the transmitter bandwidth. The system comprises a first adder into which the digital signal is fed followed by a quantizer and a compression logic. The predictive loop includes a second adder coupled to the compression logic and followed by a digital predictive filter. The output of the filter is impressed in a negative sense on the first adder and in a positive sense on the second adder. Specifically, the quantizer and compression logic may consist of a two-valued limiter followed by a compressor and a converter in the feedback loop or alternatively the limiter may be followed by a converter while the compressor is disposed outside the feedback loop to provide sample by sample compression. | |
