Using the Preamble in an OFDM-Based Communications System to Indicate the Number of Guard Tones

A method for transmitting a signal in an orthogonal frequency division multiple access (OFDMA)-based network, said method comprising:

• determining a number of guard tones used in coding a superframe preamble in said OFDMA-based network based on a channel bandwidth and a fast Fourier transform (FFT) size chosen for said channel bandwidth;
• encoding said number of guard tones into one or more acquisition pilots of said superframe preamble;
• and
• transmitting said superframe preamble in an orthogonal frequency division multiplex (OFDM) data stream.

A mobile station comprising:

• a processor;
• memory;
• an first decoding component stored in said memory, wherein said processor operates said first decoding component to decode one or more acquisition pilots in a superframe preamble of an orthogonal frequency division multiple access (OFDMA)-based network communication stream, wherein said first decoding component directs said mobile station to decode said one or more acquisition pilots prior to decoding a primary broadcast control channel (PBCCH) symbol of said superframe preamble in an OFDMA-based network;
• a guard tone code table stored in said memory, wherein said processor accesses said guard tone code table during execution of said first decoding component upon detection of a guard tone code in said decoded one or more acquisition pilots;
• and
• a second decoding component in said memory, wherein said processor operates said second decoding component to decode said PBCCH symbol of said superframe preamble using information in said guard tone code table corresponding to said guard tone code.

A base station in an orthogonal frequency division multiple access (OFDMA)-based network, said base station comprising:

• a processor;
• memory;
• a coding component operable by said processor to encode a number of guard tones used to code a superframe preamble, wherein said encoded number of guard tones is placed into one or more acquisition pilots of said superframe preamble;
• a transmitter for transmitting a communication stream including at least said superframe preamble to a plurality of mobile stations.

A computer program product having a computer readable medium with computer program logic recorded thereon, said computer program product comprising:

• code for receiving an orthogonal frequency division multiple access (OFDMA) signal stream from a base station in an OFDMA-based network;
• code for decoding one or more acquisition pilots in a superframe preamble prior to decoding a primary broadcast control channel (PBCCH) symbol;
• code for detecting a guard tone code within said decoded one or more acquisition pilots;
• and
• code for decoding said PBCCH symbol using said guard tone code.