초록 ▼

A method and system are provided for the. Transmission and reception of an In-band On-channel (IBOC) FM-band digital audio broadcast (DAB) signal. The IBOC DAB signal is generated in the transmitter to substantially occupy the upper and lower sideband frequency regions in the RF emission mask for th

A method and system are provided for the. Transmission and reception of an In-band On-channel (IBOC) FM-band digital audio broadcast (DAB) signal. The IBOC DAB signal is generated in the transmitter to substantially occupy the upper and lower sideband frequency regions in the RF emission mask for the conventional broadcast analog FM-band. Redundant source bit information is transmitted in both the upper and lower sidebands so that the loss of information in either one but not both sidebands due to large amounts of interference or distortion, caused by, for example, first-adjacent interference, does not deleteriously affect the IBOC DAB receiver performance. The system exhibits both frequency-diversity and time-diversity. The receiver determines which codeword bit estimate, corresponding to either upper or lower sideband signals, is less likely to be erroneous. The receiver system selects between decoded estimates for each pair of demodulated ECC codewords or combines both ECC codeword estimates prior to decoding in certain embodiments.

대표청구항 ▼

[ I claim:] [1.]1. A method of receiving a digitally modulated signal comprising the steps of:receiving the digitally modulated signal which has source bit information duplicated in upper and lower sidebands relative to a predetermined center frequency, the upper and lower sidebands being non-mirror

[ I claim:] [1.]1. A method of receiving a digitally modulated signal comprising the steps of:receiving the digitally modulated signal which has source bit information duplicated in upper and lower sidebands relative to a predetermined center frequency, the upper and lower sidebands being non-mirror images relative to each other;demodulating the received signals from both the upper and lower sidebands;determining which of demodulated recovered source bit information from demodulation of one of the upper and lower sideband signals is less likely to be erroneous; andselecting the sideband information from one of the demodulated upper or lower sideband signals, whichever was determined in said determining step as less likely to have errors in the demodulated or recovered source bit information.