Browse Prior Art Database

Bidirectional Spread Spectrum Communication System

IP.com Disclosure Number: IPCOM000110366D
Original Publication Date: 1992-Nov-01
Included in the Prior Art Database: 2005-Mar-25
Document File: 3 page(s) / 84K

Publishing Venue

IBM

Related People

Sakurai, T: AUTHOR

Abstract

Disclosed are bidrectional spread spectrum communication systems in which one pseudorandom sequence generator is commonly used for sending and receiving information at each terminal whereby the acquisition and tracking mechanism is eliminated in one of the terminals.

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This is the abbreviated version, containing approximately 58% of the total text.

Bidirectional Spread Spectrum Communication System

       Disclosed are bidrectional spread spectrum communication
systems in which one pseudorandom sequence generator is commonly used
for sending and receiving information at each terminal whereby the
acquisition and tracking mechanism is eliminated in one of the
terminals.

      The acquisition and tracking mechanism is one of the most
difficult parts of spread spectrum communication systems.  Usually,
the acquisition and tracking mechanism consists of a large complex
circuit.  Therefore, the cost of this portion is dominant in the
total system cost.  This disadvantage is removed by this invention.

      Fig. 1 shows the configuration of the system. Transmission of
information from terminal A to terminal B is performed with a
conventional spread spectrum communication technique.  An acquisition
and tracking mechanism 1 keeps synchronization with the spread
spectrum signal transmitted from terminal A to terminal B.
Pseudorandom sequence generator 2 generates a pseudorandom sequence
for receiving correlator 3.

      The pseudorandom sequence which is generated by pseudorandom
sequence generator 2 is also fed to spreader 4.  In transmission from
terminal B to terminal A, the information to be transmitted from
terminal B is spread with the same pseudorandom sequence as the
correlator 3 of terminal B uses.  The output signal of the spreader 4
is sent out on transmission medium 5.

      At terminal...