Method of assigning a spreading sequence to a user of a telecommunications network

• US 20060029012A1
• Filed: 10/06/2005
• Published: 02/09/2006
• Est. Priority Date: 09/13/1999
• Status: Active Grant

• Current Assignee: Damien Castelain, David Mottier
• Original Assignee: Damien Castelain, David Mottier
• Inventors: Mottier, David, Castelain, Damien
• Granted Patent: US 7,342,910 B2
• Time in Patent Office: Days
• US Class Current: 370/320
• CPC Class Codes: H04J 13/16 Code allocation
• CPC Class Codes: H04L 5/026 using code division

Abstract

The present invention on concerns a method of assigning one or more spreading sequences to a user of a Multi-Carrier Code Division Multiple Access transmission network, each element of the said sequence being, at a transmitter of the said network, multiplied by a data item to be transmitted and then transmitted on a corresponding sub-carrier. According to the present invention, it consists of assigning, to the said user, the said spreading sequence or the said spreading sequences taking into account a predetermined set of spreading sequences.

Claims

1-17. -17. (canceled)

18. A method for assigning spreading sequences to signals of an OFDM transmission network, comprising the steps of:

establishing a transmission channel that includes a plurality of signals operating on different sub-carrier frequencies

assigning at least one spreading sequence from a set of spreading sequences to data items to be transmitted on a signal in order to establish a sub-set of spreading sequences which includes less than all the spreading sequences; and

minimizing the interference between the spreading sequences by dynamically varying the sub-set of assigned spreading sequences.

19. A method according to claim 18 wherein the signal includes a signal transmitted from the antenna of a wireless OFDM transmission network.

20. A method according to claim 18 wherein the signal includes a signal transmitted from a base station to a mobile station.

21. A method according to claim 18 wherein the signal includes a signal transmitted from a mobile station to a base station.

22. A method according to claim 18 wherein the spreading sequences include Walsh-Hadamard sequences.

23. A method according to claim 18 wherein the spreading sequences include Gold sequences.

24. A method according to claim 18 wherein the spreading sequences include Kasami sequences.

25. A method according to claim 18 wherein a user is assigned to a signal operating on a specified sub-carrier frequency.

26. A method according to claim 18 wherein a cost function is used to minimize the interference.

27. A method according to claim 18 which further includes the step of using equalization to further minimize the interference.

28. A transmitter for an OFDM transmission network, comprising:

means for generating data items for a user;

means for multiplying the data items by at least one spreading sequence for each user;

means for modulating the spread sequenced data items onto a transmission channel that includes a plurality of signals operating on different sub-carrier frquencies;

wherein the data items of each user are assigned at least one spreading sequence from a set of spreading sequences to establish a subset of spreading sequences that are dynamically varied to minimize the interference between the signals operating on the sub-carrier frequencies.