Multicarrier transmission system with low power sleep mode and rapid-on capability

Abstract

A muticarrier transceiver is provided with a sleep mode in which it idles with reduced power consumption when it is not needed to transmit or receive data The full transmission and reception capabilities of the transceiver are quickly restored when needed, without requiring the full (and time-consuming) initialization commonly needed to restore such transceivers to operation after inactivity.

1 . A multicarrier transceiver having a sleep mode capability comprising: 
 means for placing at least one component of the first multicarrier transceiver in a sleep mode;    means for storing at least one parameter representative of a full power mode of said at least one component of said first multicarrier transceiver;    means for maintaining synchronization between said first multicarrier transceiver and a second multicarrier transceiver using a synchronization signal while said at least one component of said first multicarrier transceiver is in said sleep mode;    means for recovering said at least one stored parameter in response to a signal to awaken from the sleep mode; and    means for restoring said at least one component of said first multicarrier transceiver from the sleep mode to the full power mode without needing to reinitialize said first multicarrier transceiver by using said at least one recovered parameter.    
   
   
       2 . The transceiver of  claim 1 , wherein the means for placing of at least one component in the sleep mode is responsive to a sleep mode signal.  
   
   
       3 . The transceiver of  claim 2 , wherein the sleep mode signal comprises a message.  
   
   
       4 . The transceiver of  claim 1 , wherein said at least one parameter is associated with said synchronization between said multicarrier transceivers.  
   
   
       5 . The transceiver of  claim 1 , wherein said at least one parameter representative of a current operating state of said first multicarrier transceiver comprises at least one of a frequency-domain equalizer coefficient, a time-domain equalizer coefficient, an echo canceller tap, a data rate, a coding parameter, an interleaving parameter, a fine gain parameter, a subchannel gain parameter and a bit allocation table.  
   
   
       6 . The transceiver of  claim 1 , wherein the means for placing said at least one component of said first multicarrier transceiver in the sleep mode comprises means for placing said at least one component of said first multicarrier transceiver in a low power mode.  
   
   
       7 . The transceiver of  claim 1 , wherein the means for maintaining synchronization includes means for maintaining a synchronized data frame count between the first and second multicarrier transceivers.  
   
   
       8 . The transceiver of  claim 7 , wherein the means for maintaining of the synchronized data frame count includes means for using the synchronization signal to define a timing reference while said at least one component of said first multicarrier transceiver is in said sleep mode.  
   
   
       9 . The transceiver of  claim 1 , wherein the synchronization signal is a pilot tone transmitted from one of the multicarrier transceivers to the other of the multicarrier transceivers.  
   
   
       10 . The transceiver of  claim 9 , wherein the pilot tone is transmitted between said multicarrier transceivers during normal operation and sleep mode operation.  
   
   
       11 . The transceiver of  claim 1 , wherein the means for maintaining synchronization includes means for maintaining synchronization of frame counters between said multicarrier transceivers.  
   
   
       12 . The transceiver of  claim 11 , wherein the means for maintaining synchronization further includes means for maintaining synchronization of a phase of the synchronization signal transmitted between said multicarrier transceivers.  
   
   
       13 . The transceiver of  claim 1 , further comprising means for transmitting an idle symbol to said second multicarrier transceiver to indicate entry of said first multicarrier transceiver into an idle state.  
   
   
       14 . The transceiver of  claim 13 , further comprising means for maintaining synchronization between said multicarrier transceivers during the idle state.  
   
   
       15 . The transceiver of  claim 13 , wherein the idle signal is transmitted while said at least one component of said first multicarrier transceiver is in the sleep mode.  
   
   
       16 . The transceiver of  claim 1 , further comprising means for transmitting a test signal to said second multicarrier transceiver upon exiting the sleep mode.  
   
   
       17 . The transceiver of  claim 16 , further comprising means for determining, in response to the test signal, that transmission conditions have changed sufficiently while said at least one component of the first multicarrier transceiver is in the sleep mode to require re-initialization of said first multicarrier transceiver upon exiting the sleep mode.