System and method for preamble detection in MIMO narrowband power line communications

A method comprising:

• receiving a power line communication (PLC) signal stream over a first pair of power lines of a PLC network, wherein the PLC signal stream comprises a preamble, wherein the preamble has a known number K of symbols, and wherein K is an integer greater than or equal to 1;
• determining a first estimate of the preamble start by:
• placing a window of length equal to K symbols and divided into K symbol regions over the received PLC signal stream;
• and
• adding one sample in the PLC signal stream to an end of the window and removing one sample in the PLC signal stream from a beginning of the window;
• correlating the received PLC signal stream with a known preamble to generate a cross-correlation output profile;
• and
• determining a second estimate of the preamble start based on the cross-correlation output profile and further based on the first estimate of the preamble start.

A device, comprising:

• a detector configured to:
• select a sliding window that spans a known number of SYNCP and SYNCM symbols;
• move the sliding window over a power line communications (PLC) signal stream one sample at a time, the PLC signal stream received over a first pair of power lines of a PLC network;
• calculate, for each window placement, a set of delayed correlations based on a select correlation order;
• add absolute values of delayed correlations together to obtain a total correlation value for each window placement over the PLC signal stream;
• apply a threshold against the total correlation values;
• and
• select a sample index having maximum correlation as an initial estimate of a preamble start based on a maximization length parameter.

A method, comprising:

• correlating a power line communications (PLC) signal stream with a preamble to generate a cross-correlation output profile, wherein the preamble has a known number K of symbols, K is an integer greater than or equal to 1, the PLC signal stream received over a first pair of power lines of a PLC network;
• receiving a first estimate of the preamble start;
• performing a correlation between the PLC signal stream with a delayed version of the PLC signal stream by:
• placing a window of length equal to K symbols and divided into K symbol regions over the PLC signal stream, and
• adding one sample in the PLC signal stream to an end of the window and removing one sample in the PLC signal stream from a beginning of the window;
• and
• determining a second estimate of the preamble start based on the cross-correlation output profile and further based on the first estimate of the preamble start, wherein the first estimate of the preamble start is based on the correlation between the PLC signal stream with the delayed version of the PLC signal stream.