Patent ID: 11968071
Assignee: SUN PATENT TRUST
Field: Digital communication (Electrical engineering)
Classification: CPC H | IPC H

Claim 0:
1. An Orthogonal Frequency Division Multiplexing (OFDM) transmission device comprising:
a control symbol generating circuit configured to generate a first control symbol and a second control symbol such that the first control symbol includes a first useful part, a first guard interval part following the first useful part, and a first additional guard interval part preceding the first useful part and that the second control symbol includes a second useful part and a second guard interval part preceding the second useful part, the first guard interval part being a copy of at least a portion of the first useful part with frequency shifted by a first amount, the first additional guard interval part being a copy of at least a portion of the first useful part, the second guard interval part being a copy of at least a portion of the second useful part with frequency shifted by a second amount, the absolute value of the first amount and the absolute value of the second amount being the same, but one is positive and the other negative; and
an encoding and modulating circuit configured to encode and modulate a broadcast content to generate at least one information symbol different from the first control symbol and the second control symbol.