Efficient data transmission over digital telephone networks using multiple modulus conversion
US6084883A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 6, 1997 |
| Grant date | Jul 4, 2000 |
| Priority date | — |
| Expiry date | Oct 6, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/3411
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A method of encoding data into a digital sequence to be transmitted over the DTN so as to cause the DTN's codec to generate a multiple modulus M-ary signal in a manner that will facilitate efficient data transmission and recovery (decoding) by the distant end receiver, even in the presence of robbed-bit signaling (RBS). The preferred embodiments provide an apparatus and method of converting blocks of binary data to a corresponding block of M.sub.1 -ary, M.sub.2 -ary, . . . , M.sub.n symbols using Multiple Modulus Conversion (MMC) to maximize the data rate, while minimizing the required Signal-to-Noise Ratio (SNR) to achieve a desired error rate, in a system having a transmitter connected to the DTN via direct digital access and a receiver connected over a conventional analog subscriber line. A subset of codec codewords is used to represent the M-ary signals. For each time slot (symbol time) one of M separate octets are selected for transmission by the encoder, and the encoder's output is sent through the DTN to a subscriber loop codec. The value of M can vary among the different time slots. The analog output of the codec corresponds to M-level, or M-ary pulse amplitude modulation, …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.