Underrecovery system and method for block processing modems
US5793803A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 28, 1995 |
| Grant date | Aug 11, 1998 |
| Priority date | — |
| Expiry date | Sep 28, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L1/18
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A system for detecting an underrun condition in a block processing modem and upon detection retransmitting previously transmitted data or a fixed pattern of data. The system has a register or memory location that counts the symbols in a buffer located between the microprocessor and the DSP. As a symbol is added to the buffer by the microprocessor, the register is incremented. As a block of symbols is taken from the buffer by the DSP, the register decremented. Thus at any point in time, the register contains a count of the symbols in the buffer. When The DSP is ready for a next block of symbols, logic in the DSP compares the symbol count in the register and if the count is too low for the block of symbols to be passed to the DSP, the DSP itself sends either the previous set of data or a fixed pattern of data to the AFE. The error detection software operating in the software layer above the data pump detects an error and requests a retransmission.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.