WAKEUP MESSAGE FOR A DIGITAL TELEVISION SYSTEM

摘要

Methods and apparatuses are provided which utilize the preamble of a multi-carrier modulated digital transmitted signal to indicate whether or not a special message (e.g., Emergency Alert System messages) is available for reception. When in power saving mode the receiver periodically detects the preamble, which requires limited functionality and power, to check for the presence of such special messages. The receiver only completely wakes up additional functionalities if a special message is detected in the preamble. This results in advantageous savings in power consumption, particularly for portable and handheld devices, while having the capability of receiving special messages anytime.

主权项

1. An apparatus for transmitting a multi-carrier modulated signal comprising:
a source (111, 300) for providing data, said data divided into frames and comprising a wakeup message parameter which identifies whether or not a special message is included in said data; and a multi-carrier modulator (114) that modulates said data by allocating said data to a plurality of carriers in a plurality of modulation symbols, wherein the wakeup message parameter is included in at least one preamble symbol of a frame of data.