Method and apparatus for frequency domain data frame transmission

A method of transmitting data in the frequency domain on a transmission frequency band from which one or more frequency band portions are selected, by adaptive or pre-emptive selection or by allocation, for data transmission, comprising the steps of;

• inserting data bits into part of a payload portion of a data frame, leaving an unfilled part of the payload portion;
• inserting padding bits into the unfilled part of the payload portion;
• performing an error correction procession the payload portion to generate error detection bits, and inserting the error detection bits into an error detection portion of the data frame;
• and
• mapping the frame into the frequency domain for transmission such that the error detection portion and all contents of the payload portion other than the padding bits map into the selected channel portions.

A method of receiving data in the frequency domain on a transmission frequency band from which one or more frequency band portions are selected, by adaptive or preemptive selection or by allocation, for data transmission, in which data frames of a predetermined length, comprising a header and data bytes in a payload portion and error detection bytes in an error detection portion, are transmittable if all of the frequency band were used for data transmission, comprising the steps of;

• receiving from the transmission frequency band a data frame of a reduced length, less than the predetermined length, and mapping it from the frequency domain to the time domain;
• padding the payload portion of the frame with a predetermined padding bit sequence to restore the reduced-length frame to the predetermined length;
• performing error correction using the error detection bits to detect and correct any transmission errors in the data bits, where possible;
• and
• extracting the corrected data bits from the data frame.