Multi-frame synchronization for parallel channel transmissions

Abstract

The present invention comprises a method and apparatus for synchronizing data frames from a wide bandwidth data stream which is divided up and transmitted across a plurality of parallel channels in a mobile telephone system. Prior to transmitting the data frames, a transmit synchronizer synchronizes data frames aligned in the same position in different parallel channels by inserting a common bit from a repeating PN synchronization sequence into the aligned data frames. Upon receiving the data frames at a destination, a receive synchronizer extracts the synchronization bit from each data frame. A series of sequential bits from each parallel channel is compared against the original PN synchronization sequence to identify the position of each data frame relative to the other data frames and reconstructs the original wide bandwidth data stream.

What is claimed is:  
     
         1 . A method for synchronizing data frames for transmission across a plurality of parallel channels comprising the steps of: 
 grouping a set of data frames for transmission across the plurality of parallel channels wherein each data frame is transmitted on a separate parallel channel; and    inserting at least one bit from a repeating PN synchronization sequence into each data frame.    
     
     
         2 . The method recited in    claim 1   , further including the step of inserting parallel channel identity information into each data frame.  
     
     
         3 . The method recited in    claim 1   , wherein, the plurality of parallel channels comprises a mobile telephone network.  
     
     
         4 . The method recited in    claim 3   , wherein, the mobile telephone network comprises a plurality of channels in the form of time slots of a carrier frequency in a time division multiple access system.  
     
     
         5 . The method recited in    claim 3   , wherein, the mobile telephone network comprises a plurality of channels in the form of spreading codes of a carrier frequency in a code division multiple access system.  
     
     
         6 . The method recited in    claim 1   , wherein each parallel channel corresponds to a preassigned physical channel.  
     
     
         7 . The method recited in    claim 1   , wherein a common repeating PN sequence is used for all parallel channels.  
     
     
         8 . The method recited in    claim 1   , wherein each parallel channel is associated with a preassigned and distinct repeating PN synchronization sequence wherein the distinct repeating PN synchronization sequences have a known alignment to one another.  
     
     
         9 . An apparatus for synchronizing data frames for transmission across a plurality of parallel channels in a communication system, comprising: 
 means for generating a repeating PN synchronization sequence; and    a transmit synchronizer for grouping sets of data frames for transmission across the plurality of parallel channels with each of the data frames within the set being transmitted across a separate parallel channel, the transmit synchronizer inserting bits from the repeating PN synchronization sequence into the data frames.    
     
     
         10 . The apparatus recited in    claim 9   , further comprising means for inserting parallel channel identity information into each data frame.  
     
     
         11 . The apparatus recited in    claim 9   , wherein the communication system comprises a mobile telephone system.  
     
     
         12 . The apparatus recited in    claim 11   , wherein the mobile telephone system has a Time Division Multiple Access air interface and a channel comprises a distinct time slot of the carrier frequency.  
     
     
         13 . The apparatus recited in    claim 11   , wherein the mobile telephone system has a code division multiple access air interface and a channel comprises a distinct spreading code.  
     
     
         14 . A method for synchronizing data frames received across a plurality of parallel channels, comprising the steps of: 
 extracting at least one PN synchronization sequence bit from each of the data frames received across the plurality of parallel channels to form a synchronization sequence for each of the parallel channels;    identifying a unique sequence for each of the parallel channels from the PN synchronization sequence bits extracted from sequential data frames received across the respective parallel channels;    comparing the positions of the unique sequences identified from each of the channels against each other; and    aligning the data frames based on the relative positions of the unique sequences.    
     
     
         15 . The method recited in    claim 14   , further including the step of extracting parallel channel identity information from each of the data frames.  
     
     
         16 . The method recited in    claim 14   , further including the step of determining the identity of the parallel channels based on which physical channel the data frames were received on.  
     
     
         17 . The method recited in    claim 14   , further comprising the step of determining the identity of the parallel channels based on a preassigned and distinct PN synchronization sequence associated with each channel.  
     
     
         18 . An apparatus for synchronizing data frames received across a plurality of parallel channels, comprising: 
 means for generating a repeating PN synchronization sequence; and    a receive synchronizer for extracting PN synchronization sequence bits from received data frames and identifying unique sequences for each of the parallel channels, the receive synchronizer using the identified unique sequences to align the received data frames to regroup sets of transmitted data frames. unique sequences to align the received data frames to regroup sets of transmitted data frames.    
     
     
         19 . The apparatus recited in    claim 18   , further comprising means for determining a parallel channel identity based on information extracted from each data frame.  
     
     
         20 . The apparatus recited in    claim 18   , further comprising means for determining a parallel channel identity based on a preassigned and distinct PN synchronization sequence associated with each channel.