Multiple access method
AssigneeAscom Tech AG
InventorJames L. Massey
Life of this patent
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AssigneeAscom Tech AG
InventorJames L. Massey
Estimating the term…
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.
Multiple access method for the simultaneous exchange of several data streams among several participants of a transmission system, wherein various data streams with the same spread sequence are expanded to a corresponding DSSS signal, and the various DSSS signals are superimposed during transmission to a single incoming signal, characterized in that, for detecting the different data streams in a receiver, the incoming signal is filtered in a filter that is inverse with respect to the joint spread sequence, and that the superposition takes place in such a way that the spread sequence intervals pertaining to different data streams are time-shifted with respect to one another by a predetermined minimum value.
A mobile radio system having at least one base station and several subscriber stations for the simultaneous exchange of several data streams among the several subscriber stations of the mobile radio system, wherein various data streams with the same spread sequence intervals are expanded to a corresponding DSSS signal, and the various DSSS signals are superimposed during transmission to an single incoming signal, comprising
Dependencies are inferred from the claim text.