Building, transmitting, and receiving frame structures in power line communications
Methods for building, transmitting, and receiving frame structures in power line communications (PLC) are described. Various techniques described herein provide a preamble design using one or more symbols. One or more preamble symbols may be interspersed within a header portion of a PLC frame to facilitate estimation of a frame boundary and/or sampling frequency offset, for example, in the presence of impulsive noise.
1. A method comprising:
identifying, by a power line communication (PLC) device, a first PLC symbol and a second PLC symbol within a PLC preamble;
inserting, by the PLC device, an instance of the first PLC symbol within a PLC header portion of a first PLC frame;
inserting, by the PLC device, an instance of the second PLC symbol within the PLC header portion of the first PLC frame;
transmitting, by the PLC device, the first PLC frame over a power line;
receiving a second PLC frame;
locating a position of a PLC preamble symbol within a header portion of the second PLC frame; and
estimating a sampling frequency offset based on the located position of the PLC preamble symbol.
2. The method of claim 1 , wherein:
inserting the instance of the first PLC symbol is at a predetermined location within the PLC header portion of the first PLC frame.
3. The method of claim 2 , further comprising:
inserting a second instance of the first PLC symbol at second location within the PLC header portion of the PLC frame.
4. The method of claim 2 , further comprising:
inserting the instance of the second PLC symbol at predetermined second location within the PLC header portion of the PLC frame.
5. The method of claim 2 , further comprising:
estimating a start of the second PLC frame or a sampling frequency offset based on the located position of the PLC preamble symbol.
6. The method of claim 2 , wherein the PLC device is a PLC modem.
7. The method of claim 2 , wherein the PLC device is a gateway.
8. The method of claim 2 , wherein the PLC device is a PLC data concentrator.
9. The method of claim 2 , wherein the PLC device is implemented at least in part as an integrated circuit (IC).
10. The method of claim 9 , wherein the IC is a digital signal processor (DSP).
11. The method of claim 9 , wherein the IC is an application specific integrated circuit (ASIC).
12. The method of claim 9 , wherein the IC is a system on a Chip (SoC) circuit.
13. The method of claim 9 , wherein the IC is a field programmable gate array (FPGA).
14. The method of claim 9 , wherein the IC is a microprocessor.
15. The method of claim 9 , wherein the IC is a microcontroller.