Method and system for maximizing data throughput rate in a power line communications system by modifying payload symbol length

Abstract

Data throughput rate in a power line communications (“PLC”) system is controlled by generating PLC carrier signals in accordance with a PLC signal frame structure containing payload symbols where the payload symbol length is selected based on at least one of a PLC system channel quality and node configuration data. The selected payload symbol length determines the processing operations that a source PLC transceiver performs for generating PLC signals or that a destination PLC transceiver performs for extracting information content from received PLC signals. The payload symbol lengths can be selected to maximize the data throughput rate while maintaining compatibility with prior art PLC system protocols and standards that require a PLC signal frame structure and its payload portion to have fixed, predetermined lengths.

1 . A method for transferring data on power line communications (“PLC”) signals over a PLC system, wherein the PLC system operates in accordance with a PLC signal frame structure including a payload portion and wherein the payload portion has a predetermined, fixed length and includes at least one payload symbol, the method comprising: 
 obtaining channel quality data for a PLC system signal path extending between a source PLC transceiver and a destination PLC transceiver;    computing, based on at least one of the channel quality data and node configuration data, a payload symbol length;    generating a payload portion including at least one payload symbol of the computed length, wherein the length or sum of the lengths of the at least one payload symbol contained in the generated payload portion equals the predetermined length of the payload portion; and    modifying processing operations at the source PLC transceiver for generating PLC carriers in accordance with the PLC signal frame structure including the at least one payload symbol having the computed payload length.    
     
     
         2 . The method of  claim 1  further comprising: 
 modifying processing operations at the destination PLC transceiver for extracting data from the PLC signal frame structure based on the computed length payload symbol.    
     
     
         3 . The method of  claim 1 , wherein the source PLC transceiver operates in a default mode for generating PLC carriers based on a PLC signal frame structure including payload symbols having a first length, wherein the computed payload symbol length exceeds the first length, thereby increasing PLC data throughput rate and efficiency of utilization of the PLC system as a channel for transferring communications data.  
     
     
         4 . The method of  claim 1 , wherein the destination PLC transceiver operates in a default mode for extracting information content from a received PLC signal generated based on a PLC frame structure including payload symbols having a first length, wherein the computed payload symbol length exceeds the first length.  
     
     
         5 . The method of  claim 1  further comprising: 
 transmitting from the PLC source transceiver, over the PLC system and for receipt at the destination PLC transceiver, PLC carriers generated in accordance with the frame structure;    determining at the destination PLC transceiver, from the PLC carriers transmitted from the source PLC transceiver, whether the payload symbols used to generate the received PLC carriers have a length other than a default mode payload symbol length; and    at the destination PLC transceiver, extracting information content data from the received PLC carriers based on the payload length determination.    
     
     
         6 . The method of  claim 3  further comprising: 
 generating a predetermined number of distinct PLC carriers based on the computed payload symbol length, wherein the predetermined number of PLC carriers exceeds an available number of distinct PLC carriers generated during operation of the source PLC transceiver in the default mode.    
     
     
         7 . The method of  claim 6 , wherein the predetermined number of distinct PLC carriers have a narrower bandwidth than the bandwidth of the PLC carriers generated during operation of the source PLC transceiver in the default mode.  
     
     
         8 . The method of  claim 6 , wherein the predetermined number of distinct frequency PLC carriers are distributed across a PLC frequency spectrum broader than a PLC frequency spectrum required by the default mode.  
     
     
         9 . The method of  claim 3  further comprising: 
 increasing a sampling rate of a clock included in the source PLC transceiver to a rate exceeding a sampling rate associated with the default mode.    
     
     
         10 . The method of  claim 8 , wherein the predetermined number of distinct PLC carriers has a narrower bandwidth than the bandwidth of the PLC carriers generated during operation of the source PLC transceiver in the default mode.  
     
     
         11 . The method of  claim 9 , wherein the predetermined number of distinct PLC carriers has a narrower bandwidth than the bandwidth of the PLC carriers generated during operation of the source PLC transceiver in the default mode.  
     
     
         12 . The method of  claim 1 , wherein the source PLC transceiver operates in a default mode for generating PLC carriers based on a PLC signal frame structure including payload symbols having a first length, wherein the computed payload symbol length is less than the first length.  
     
     
         13 . The method of  claim 1 , wherein the PLC system includes power and communications data distribution components operating in accordance with at least one operating mode.  
     
     
         14 . The method of  claim 1 , wherein the at least one operating mode includes PLC system operation in accordance with processing capabilities at a range of processing speeds.  
     
     
         15 . The method of  claim 1 , wherein the PLC carriers have frequencies within a PLC frequency spectrum extending between about 2 MHz and about 30 MHz.  
     
     
         16 . A power line communications (“PLC”) transceiver for transferring, over a PLC system, PLC signals generated in accordance with a PLC signal frame structure including a payload portion, wherein the payload portion has a predetermined, fixed length and includes at least one payload symbol, the PLC transceiver comprising: 
 a channel estimator for obtaining channel quality data for a PLC system signal path extending to a destination PLC transceiver;    a symbol length controller coupled to the channel estimator and for computing, based on at least one of the channel quality data and node configuration data stored in the symbol length controller, a payload symbol length, wherein the computed payload symbol length is used for generating a payload portion including at least one payload symbol of the computed length, wherein the length or sum of the lengths of the at least one payload symbol contained in the generated payload portion equals the predetermined length of the payload portion; and    a PLC carrier generator coupled to the symbol length controller for generating PLC carriers containing information content, wherein the symbol length controller supplies the PLC signal generator with control signals for modifying processing operations in accordance with a PLC signal frame including the at least one payload symbol having the computed symbol length.    
     
     
         17 . The PLC transceiver of  claim 16 , wherein the PLC carrier generator normally operates in a default mode, wherein in the default mode a payload symbol has a predetermined length.  
     
     
         18 . The PLC transceiver of  claim 17 , wherein the computed payload symbol length exceeds or is less than the predetermined payload symbol length for the default mode.  
     
     
         19 . The PLC transceiver of  claim 16 , wherein the PLC carrier generator further comprises a reprogrammable forward error correction (“FEC”) encoder and a reprogrammable FEC decoder capable of being programmed to perform PLC processing on data blocks containing information content data in accordance with a selected payload symbol length, wherein the data blocks are selected from at least one of a predetermined number of sizes.  
     
     
         20 . The PLC transceiver of  claim 16 , wherein the PLC carrier generator further comprises a reprogrammable interleaver module and a reprogrammable deinterleaver module which are coupled respectively to the FEC encoder and FED decoder, wherein each of the interleaver and deinterleaver modules is capable of being programmed to perform PLC signal processing on data blocks containing information content data in accordance with a selected payload symbol length.  
     
     
         21 . The PLC transceiver of  claim 16  further comprising: 
 a computer processing unit (“CPU”) coupled to the symbol length controller and the PLC carrier generator, wherein the CPU controls Phy layer software operations and performs channel quality assessment operations.