Code time division Multiple Access System



In a multiple access method for the simultaneous exchange of several data streams ({B.sub.1,m }, {B.sub.2,m }, {B.sub.3,m }) among several participants of a transmission system, various data streams ({B.sub.1,m }, {B.sub.2,m }, {B.sub.3,m }) with the same spread sequence (s[.]) are expanded to a corresponding DSSS signal ({B.sub.1,m s[.]}, {B.sub.2,m s[.]}, {B.sub.3,m s[.]}. During transmission, the various DSSS signals ({B.sub.1,m s[.]}, {B.sub.2,m s[.]}, {B.sub.3,m s[.]}) are heterodyned to a single incoming signal. For detecting the various data streams in a receiver, the incoming signal is filtered in a filter that is inverse with respect to the joint spread sequence (s[.]). In order to permit reliable detection, heterodyning takes place in each case so that the spread sequence intervals pertaining to different data streams are chronologically shifted with respect to one another by a given minimum value (delta.sub.– T). The invention provides a multiple access method combining therein the advantages of TDMA and CDMA. In particular, an almost complete separation of the users is possible without requiring the precision of synchronization customary in case of TDMA.


Attribute NameValues
  • Code time division Multiple Access System

Patent Number
  • EP 0486834B1

  • James L. Massey

Inventor From Local Institution
  • James L. Massey

  • 9

International Patent Classification codes
  • H04J 13/00 (20060101); H04J 13/02 (20060101); H04N 001/00 ()

  • German

  • English

  • French

Date Issued
  • 1990-11-22

  • European Patent Office

  • Ascom Tech AG

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James L. Massey Memorial Collection


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