Methods (900, 1000) and apparatuses (110, 120, 400) are provided for transmitting and receiving a signal. The method (900) of transmitting a signal includes modulating (920) data into a plurality of modulation symbols to generate a signal, the data including time synchronization information including one of a time offset parameter and a frame length parameter selected according to a frame length mode parameter, and transmitting (930) the signal over a communication medium. The method (1000) of receiving a signal includes receiving (1010) a signal over a communication medium, and demodulating (1020) the signal to generate a plurality of demodulated symbols, the demodulated symbols including data, the data including time synchronization information including one of a time offset parameter and a frame length parameter selected according to a frame length mode parameter.