Method and apparatus for digital audio broadcasting and reception
US5278844A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 11, 1991 |
| Grant date | Jan 11, 1994 |
| Priority date | — |
| Expiry date | Apr 11, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2001/0093
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A radio broadcasting system is provided for transmitting and receiving through free space a fully coherent multicarrier modulated digital signal which is especially adapted to be resistive to multipath degradation. The multicarrier modulated signal is a synthesized vector-modulated signal which is a quadrature phase shift keyed (QPSK) modulated set of synthesized carriers phase coherent with each other and each occupying a spectrum replicated multiple times within a bandwidth with no more than two bits per vector. An efficient channel coding consisting of large block size, high efficiency block coding, such as BCH 255, 239 code, is employed in connection with time interleaving of bits to mitigate the effects of frequency selective multipath and broadband multipath. The broadcast system is designed to be used in support of compressed digital audio programming material. In a demodulation process according to the invention, a demodulator is operative to phase lock to a reconstructed or otherwise coherent pilot tone or equivalent clock, to coherently demodulate the digital signal, to deinterleave, to decode the block encoded signal and to format the recovered data stream for source dec…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.