Method and apparatus for providing signal acquisition and frame synchronization in a hierarchical modulation scheme
US7907641B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 7, 2004 |
| Grant date | Mar 15, 2011 |
| Priority date | — |
| Expiry date | Jul 23, 2027 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L7/048
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
An approach is provided for supporting signal acquisition and frame synchronization in a digital broadcast system utilizing Low Density Parity Check (LDPC) codes. Hierarchical modulation is utilized to provide backward compatibility, whereby the lower layer signal is encoded using LDPC coding. A signal is received, whereby the signal is modulated according to the hierarchical modulation scheme including an upper layer and a lower layer. The signal includes a data pattern and a coded frame. The dependency of the received signal on the upper layer modulation is removed. The modulation removed signal is correlated with multiple predetermined data patterns to determine the data pattern of the signal. The code rate of the coded frame is derived based on the determined data pattern. The above arrangement is particularly suited to a digital satellite broadcast system.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.