US Patent 7660331 Method and apparatus for aligning communication signals

A pilot signal is prepended to a communication signal to form a test signal. The test signal is transmitted through a communication network and received from the communication network. A temporal marker in the pilot signal portion of the received test signal is identified. The communication signal portion of the received test signal is known to begin at a specified time following the temporal marker. Using the identified temporal marker and the specified time, a beginning of the communication signal portion is identified within the received test signal. The identified beginning of the communication signal portion in the received test signal is then aligned with a beginning of an undegraded version of the communication signal.