Symbol and frame synchronization for power-line communications

An embodiment is a method and apparatus to perform symbol synchronization. A correlation estimator computes a correlation of a sample vector representative of a narrowband signal. A synchronization detector detects symbol synchronization. Another embodiment is a method and apparatus to perform frame synchronization. A Fast Fourier Transform (FFT) processing unit computes a current FFT vector and an accumulated previous FFT vector. The current FFT vector and the accumulated previous FFT vector correspond to sample vectors associated with preamble symbols. A real and imaginary processing unit generates real and imaginary summations using the current FFT vector and the accumulated previous FFT vector. A mode processor generates mode flags representing operational modes using the real and imaginary summations.