Distributed control in synchronizing remote units to host unit

Abstract

A bi-directional communication system is provided. The system includes a multipoint-to-point host unit and a plurality of remote units communicatively coupled to the multipoint-to-point host unit through an orthogonal frequency division multiplexing waveform. The multipoint-to-point host unit is configured to receive the orthogonal frequency division multiplexing waveform, the orthogonal frequency division multiplexing waveform comprising a plurality of tones transmitted by the plurality of remote units. The multipoint-to-point host unit is configured to adjust transmissions from at least one of the plurality of remote units based on the orthogonal frequency division multiplexing waveform so that the plurality of tones transmitted by the plurality of remote units are substantially orthogonal when received at the multipoint-to-point host unit.

1 . A bidirectional communication system, the system comprising: 
 a first remote unit for communicating with a host unit using orthogonal frequency division multiplexing, the host unit communicatively coupled to a plurality of remote units in a multipoint-to-point configuration;    wherein the first remote unit is configured to transmit up to a plurality of tones, the up to a plurality of tones modulated with upstream information using orthogonal frequency division multiplexing;    wherein the first remote unit is configured to receive information from the host unit to adjust transmission of the up to a plurality of tones.    
     
     
         2 . The system of  claim 1 , the first remote unit including a modulator for modulating up to a plurality of tones with upstream information using orthogonal frequency division multiplexing such that when any tones are transmitted from the first remote unit and at least one other remote unit of the plurality of remote units, the tones are substantially orthogonal when received at the host unit.  
     
     
         3 . The system of  claim 1 , and further comprising a distribution network coupled between the host unit and the plurality of remote units.  
     
     
         4 . The system of  claim 3 , wherein the distribution network comprises one of a wireless system and a hybrid fiber/coax network.  
     
     
         5 . The system of  claim 1 , wherein the plurality of tones are transmitted concurrently from at least two of the plurality of remote units.  
     
     
         6 . The system of  claim 1 , wherein the first remote unit is configured to receive information from the host unit that is derived from prior transmissions from the first remote unit to the host unit.  
     
     
         7 . A bidirectional communication system, the system comprising: 
 a host unit to communicate with a plurality of remote units using orthogonal frequency division multiplexing, the plurality of remote units communicatively coupled to the host unit in a multipoint-to-point configuration;    the host unit receiving an orthogonal frequency division multiplexing waveform, the orthogonal frequency division multiplexing waveform comprising a plurality of tones transmitted by the plurality of remote units;    wherein the host unit is configured to transmit information to at least one of the plurality of remote units, the information directing the at least one of the plurality of remote units make a transmission adjustment to at least one tone of the plurality of tones.    
     
     
         8 . The system of  claim 7 , and further comprising a distribution network coupled between the host unit and the plurality of remote units.  
     
     
         9 . The system of  claim 8 , wherein the distribution network comprises one of a wireless system and a hybrid fiber/coax network.  
     
     
         11 . The system of  claim 7 , wherein the host unit further determines the transmission adjustment based on prior transmissions from the at least one of the plurality of remote units.  
     
     
         12 . The system of  claim 7 , wherein the host unit determines the transmission adjustments to adjust at least one of carrier frequency, power amplitude and timing of the at least one of the plurality of remote units.  
     
     
         13 . The system of  claim 7 , wherein the plurality of tones are transmitted concurrently from at least two of the plurality of remote units.  
     
     
         14 . A bi-directional communication system, the system comprising: 
 a multipoint-to-point host unit; and    a plurality of remote units communicatively coupled to the multipoint-to-point host unit through an orthogonal frequency division multiplexing waveform;    wherein the multipoint-to-point host unit is configured to receive the orthogonal frequency division multiplexing waveform, the orthogonal frequency division multiplexing waveform comprising a plurality of tones transmitted by the plurality of remote units;    wherein the multipoint-to-point host unit is configured to adjust transmissions from at least one of the plurality of remote units based on the orthogonal frequency division multiplexing waveform so that the plurality of tones transmitted by the plurality of remote units are substantially orthogonal when received at the multipoint-to-point host unit.    
     
     
         15 . The system of  claim 14 , wherein the plurality of remote units are configured to modulate a plurality of tones with upstream information so that when the plurality of tones are transmitted from at least two of the plurality of remote units, the plurality of tones are substantially orthogonal when received at a multipoint-to-point host unit.  
     
     
         16 . The system of  claim 14 , wherein the plurality of tones are transmitted concurrently from at least two of the plurality of remote units.  
     
     
         17 . The system of  claim 14 , and further comprising a distribution network coupled between the multipoint-to-point host unit and the plurality of remote units.  
     
     
         18 . The system of  claim 17 , wherein the distribution network comprises one of a wireless system and a hybrid fiber/coax network.  
     
     
         19 . The system of  claim 14 , wherein the multipoint-to-point host unit is configured to determine the adjustments for the at least one of the plurality of remote units based on prior transmissions from the at least one of the plurality of remote units.  
     
     
         20 . The system of  claim 14 , wherein the multipoint-to-point host unit is configured to determine adjustments to at least one of carrier frequency, power amplitude and timing for the at least one of the plurality of remote units.