Packet-switched spread-spectrum system

Abstract

A system and method for encoding and transmitting data with a spread-spectrum packet-switched system. Data to be transmitted by a packet transmitter are encoded for privacy and to restrict intelligent receipt of the data to the intended recipient. The encoded data is demultiplexed into sub-data-sequence signals which are spread-spectrum processed and then combined as a multichannel spread-spectrum signal. The multichannel spread-spectrum signal is concatenated with a header to output a packet-spread-spectrum signal which is transmitted over radio waves to a packet receiver. The packet receiver obtains timing for the multichannel spread-spectrum signal from the header. The multichannel spread-spectrum signal is then despread and multiplexed as received-encoded data. The received-encoded data is decoded by the intended recipient and stored in a receiver memory for output.

1 . A packet-switched system for communicating data, comprising: 
 a plurality of packet transmitters, each packet transmitter including, 
 a transmitter-first-in-first-out (transmitter-FIFO) memory, coupled to a data input, for storing data;  
 an encoder, coupled to said transmitter-FIFO memory, for encoding the data from said transmitter-FIFO memory as encoded data;  
 a demultiplexer, coupled to said encoder and having a plurality of outputs, for demultiplexing the encoded data into a plurality of sub-data-sequence signals, with a respective sub-data-sequence signal at a respective output of said demultiplexer;  
 chip-sequence means for outputting a plurality of chip-sequence signals, with each chip-sequence signal orthogonal to the other chip-sequence signals in said plurality of chip-sequence signals;  
 a plurality of product devices, coupled to the plurality of outputs of said demultiplexer, respectively, and to said chip-sequence means, for multiplying each of the sub-data-sequence signals by a respective chip-sequence signal, thereby generating a plurality of spread-spectrum channels;  
 a combiner, coupled to the plurality of product devices, for algebraically combining the plurality of spread-spectrum channels as a multichannel-spread-spectrum signal;  
 a header device, coupled to said combiner, for concatenating a header for chip-sequence synchronization, to the multichannel-spread-spectrum signal, thereby generating a packet-spread-spectrum signal; and  
 a transmitter subsystem, coupled to said header device, for transmitting on a carrier frequency the packet-spread-spectrum signal using radio waves over a communications channel; and  
   a plurality of packet receivers, each packet receiver including, 
 a translating device, coupled to the communications channel, for translating the packet-spread-spectrum signal from the carrier frequency to a processing frequency;  
 a header-matched filter, coupled to said translating device and having an impulse response matched to the header, for detecting, at the processing frequency, the header in the packet-spread-spectrum signal, and for outputting, responsive to detecting the header, a header-detection signal;  
 a processor, coupled to said header-matched filter, responsive to the header-detection signal, for generating control and timing signals;  
 a plurality of data-matched filters, coupled to said translating device, with each data-matched filter having an impulse response matched to a chip-sequence signal of the plurality of chip-sequence signals, respectively, for despreading the multichannel-spread-spectrum signal embedded in the packet-spread-spectrum signal as a plurality of received spread-spectrum channels, respectively;  
 a multiplexer, coupled to said plurality of data-matched filters, for multiplexing the plurality of received spread-spectrum channels as received-encoded data;  
 a decoder, coupled to said multiplexer, for decoding the received-encoded data as received data; and  
 a receiver-FIFO memory, coupled to said decoder, for storing the received data, and for outputting the received data to a data output.  
   
   
   
       2 - 15 . (canceled)