Filtering identifier for an OFDM system
AssigneeInterDigital CE Patent Holdings, SAS
InventorsJohn Sidney Stewart, Loic Fontaine, Anthony Pesin
Life of this patent
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Abstract
A broadcast TV signal is a DVB-T2 based system. A DVB-T2 transmitter checks OFDM symbols before transmission to determine a level of adjacent channel interference (ACI). If the of level of ACI is too high, i.e., above a threshold value, the OFDM symbols are filtered before transmission. Otherwise, the OFDM symbols are transmitted without filtering. A filtering field is added to an LI pre-signaling table of the broadcast DVB-T2 signal to signal a DVB-T2 receiver when the received OFDM symbols have been filtered.
Claims6
A receiver comprising:
- an orthogonal frequency division multiplexed (OFDM) receiver for receiving an OFDM broadcast signal, the received OFDM broadcast signal conveying frames, each frame comprising a preamble portion and a following data portion;
- wherein at least one preamble portion conveys information to the receiver if a following data portion has, or has not, been filtered prior to transmission;
- and
- a processor, responsive to the information if a following data portion has, or has not, been filtered prior to transmission, for controlling a filter to process the following data portion to compensate for being filtered prior to transmission.
A method for use in a receiver, the method comprising:
- receiving an orthogonal frequency division multiplexed (OFDM) broadcast signal, the received OFDM broadcast signal conveying frames, each frame comprising a preamble portion and a following data portion;
- wherein at least one preamble portion conveys information to the receiver if a following data portion has, or has not, been filtered prior to transmission;
- and
- responsive to the information if a following data portion has, or has not, been filtered prior to transmission, filtering the following data portion to compensate for being filtered prior to transmission.
Dependencies are inferred from the claim text.