Direct sequence network and method using PN sequence selection to represent data

• US 6,005,883 A
• Filed: 01/26/1996
• Issued: 12/21/1999
• Est. Priority Date: 01/26/1996
• Status: Expired due to Term

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Aironet Wireless Communications, Inc. (Cisco Systems, Inc.)
• Inventors: Trompower, Michael L.
• Primary Examiner(s): Chin, Stephen
• Assistant Examiner(s): Roundtree, Joseph
• Application Number:
  US08/592,130
• Time in Patent Office: 1,425 Days
• Field of Search: 370/209, 370/242, 370/479, 375/200, 375/206, 375/208, 455/7, 455/13.1, 455/23, 455/32.2, 455/33.3, 455/524
• US Class Current: 375/141
• CPC Class Codes: H04B 1/707 using direct sequence modulation

Abstract

A direct sequence spread spectrum (DSSS) system which uses PN sequences to encode data so as to increase data throughput. In particular, a system for communicating a plurality of data values using multiple spreading sequences is provided. The system transmits data by selecting at least one of the multiple spreading sequences based on at least one data value included in the plurality of data values; and transmitting other data values included in the plurality of data values using the at least one of the multiple spreading sequences to spread the other data values.

Claims

1. A method for communicating a plurality of data values using multiple spreading sequences, comprising the steps of:

selecting at least one of the multiple spreading sequences based on at least one data value included in the plurality of data values; and

transmitting other data values included in the plurality of data values using the at least one of the multiple spreading sequences to spread the other data values.

2. The method of claim 1, further comprising the steps of:

receiving the other data values;

detecting the at least one of the multiple spreading sequences used to spread the other data values; and

reconstructing the plurality of data values based at least in part on the other data values received and the detected at least one of the multiple spreading sequences.

3. The method of claim 2, wherein each of the multiple spreading sequences has a unique data value associated therewith.

4. The method of claim 1, wherein the multiple spreading sequences comprise at least three spreading sequences.

5. The method of claim 1, wherein the other data values are transmitted using BPSK modulation.

6. The method of claim 5, wherein the plurality of data values comprises a sequence of data bits, the value of every other data bit in the sequence determines which of the multiple spreading sequences is selected in the selecting step, and the selected at least one of the spreading sequences is used to spread a data bit adjacent the every other data bit in the transmitting step.

7. The method of claim 5, wherein the plurality of data values comprises a sequence of data bits, the values of at least three out of every five consecutive data bits in the sequence determines which of the multiple spreading sequences is selected in the selecting step, and the selected at least one of the spreading sequences is used to spread other data bits.

8. The method of claim 1, wherein the spread portion of the other data values are transmitted using QPSK modulation.

9. The method of claim 8, wherein the plurality of data values comprises a sequence of data bits, the values of at least one of every three consecutive data bits in the sequence determines which of the multiple spreading sequences is selected in the selecting step, and the selected at least one of the spreading sequences is used to spread other data bits.

10. The method of claim 8, wherein the plurality of data values comprises a sequence of data bits, the values of at least three out of every seven consecutive data bits in the sequence determines which of the multiple spreading sequences is selected in the selecting step, and the selected at least one of the spreading sequences is used to spread other data bits.

11. A device for communicating a plurality of data values using multiple spreading sequences, comprising:

a selection circuit for selecting at least one of the multiple spreading sequences based on at least one data value included in the plurality of data values; and

a transmitting circuit for transmitting other data values included in the plurality of data values using the at least one of the multiple spreading sequences to spread the other data values.

12. The device of claim 11, further comprising:

a receiving circuit for receiving the spread other data values;

a detector circuit for detecting among a plurality of spreading sequences which spreading sequences were used to spread the received other data values; and

a circuit for constructing a plurality of data values based at least in part on the received spread portion of data values and the detected spreading sequences, wherein the number of constructed data values exceeds the number of received other data values.

13. The device of claim 12, wherein each of the multiple spreading sequences has a unique data value associated therewith.

14. The device of claim 11, wherein the multiple spreading sequences comprise at least three spreading sequences.

15. The device of claim 11, wherein the spread other data values are transmitted by the transmitter circuit, using BPSK modulation.

16. The device of claim 15, wherein the plurality of data values comprises a sequence of data bits, the selection circuit uses the value of every other data bit in the sequence to determine which of the multiple spreading sequences is selected, and the selected at least one of the spreading sequences is used by the transmitter circuit to spread a data bit adjacent the every other data bit.

17. The device of claim 15, wherein the plurality of data values comprises a sequence of data bits, the selection circuit uses the values of at least three out of every five consecutive data bits in the sequence to determine which of the multiple spreading sequences is selected, and the selected at least one of the spreading sequences is used by the transmitter circuit to spread other data bits.

18. The device of claim 11, wherein the spread other data values are transmitted by the transmitter circuit using QPSK modulation.

19. The device of claim 18, wherein the plurality of data values comprises a sequence of data bits, the selection circuit uses the values of at least one of every three consecutive data bits in the sequence to determine which of the multiple spreading sequences is selected, and the selected at least one of the spreading sequences is used by the transmitter circuit to spread other data bits.

20. The device of claim 18, wherein the plurality of data values comprises a sequence of data bits, the selection circuit using the values of at least three out of every seven consecutive data bits in the sequence to determine which of the multiple spreading sequences is selected, and the selected at least one of the spreading sequences is used by the transmitter circuit to spread other data bits.

21. The device of claim 11, wherein the transmitter circuit comprises a radio frequency transmitter.

22. A network comprising a plurality of devices as recited in claim 12.

23. The network of claim 22, wherein each of the devices comprises a radio frequency transmitter circuit and receiver circuit.

24. A cellular communication system, comprising:

a network;

a host computer coupled to said network;

a plurality of base stations coupled to said network and communicating with said host computer, each of the base stations comprising a base station transmitter system for transmitting wireless communications and a base station receiver system for receiving wireless communications; and

a plurality of mobile terminals each for communicating with the network by way of at least one of the plurality of base stations, each of the plurality of mobile terminals having a mobile terminal transmitter for transmitting wireless communications to the at least one of the plurality of base stations and a mobile terminal receiver system for receiving wireless communications from the at least one of the plurality of base stations;

wherein, with respect to at least one of the mobile terminals, at least one of the mobile terminal transmitter systems wirelessly communicates a set of data having a first subset and a second subset different than the first subset by selectively encoding each data bit of said second subset with one of one or more spreading sequences selected by said first subset and wirelessly transmitting said encoded second subset.

25. The cellular communication system of claim 24, wherein with respect to at least one of the base stations, at least one of the base stations receiver systems receives said second subset and reconstructs said set of data based on said second subset and said one or more spreading sequences.

26. The cellular communication system of claim 25, wherein said cellular communication system is a direct sequence spread spectrum system.

27. The cellular communication system of claim 26, wherein each of said one or more spreading sequences is an eleven chip pseudo-noise code.

28. A cellular communication system, comprising:

a network;

a host computer coupled to said network;

a plurality of base stations coupled to said network and communicating with said host computer, each of the base stations comprising a base station transmitter system for transmitting wireless communications and a base station receiver system for receiving wireless communications; and

a plurality of mobile terminals each for communicating with the network by way of at least one of the plurality of base station, each of the plurality of mobile terminals having a mobile terminal transmitter for transmitting wireless communications to the at least one of the plurality of base stations and a mobile terminal receiver system for receiving wireless communications from the at least one of the plurality base stations;

wherein, with respect to at least one of the base stations, at least one of the base station transmitter systems wirelessly communicates a set of data having a first subset and a second subset different than the first subset by selectively encoding each data bit of said second subset with one of one or more spreading sequences selected by said first subset and wirelessly transmitting said encoded second subset.

29. The cellular communication system of claim 28, wherein with respect to at least one of the mobile terminals, at least one of the mobile terminal receiver systems receives said second subset and reconstructs said set of data based on said second subset and said one or more spreading sequences.

30. The cellular communication system of claim 29 wherein said cellular communication system is a direct sequence spread spectrum system.

31. The cellular communication system of claim 28 wherein said second subset is transmitted using a BPSK modulation technique.

32. A method of encoding a set of data bits for transmission in a cellular communication system, said set of data bits comprising a first subset of data bits and a second subset of data bits, said method comprising the steps of:

preselecting two or more spreading sequences;

preassigning a unique value to each of one or more different arrangements of said preselected two or more spreading sequences, each of said unique values representing one or more data bits;

representing said first subset of data bits with one of said one or more different arrangements of said preselected two or more spreading sequences in accordance with a predefined relationship between said first subset of data bits and said preassigned unique values; and

encoding said second subset of data bits based on the one arrangement of said preselected two or more spreading sequences representing said first subset of data bits.

33. The method of claim 32, further comprising the step of repeating said preselecting, preassigning, representing and encoding steps for each of a plurality of sets of data bits included in a sequence of data bits.

34. The method of claim 32, further comprising the step of BPSK modulating said encoded second subset of data bits.

35. The method of claim 32, further comprising the step of QPSK modulating said encoded second subset of data bits.

36. The method of claim 32, wherein said preselected two or more spreading sequences comprises at least three spreading sequences.

37. A method of communicating in a cellular communication system using multiple spreading sequences, comprising the steps of:

selecting a set of data bits to be communicated, said set of data bits consisting of a first subset of data bits and a second subset of data bits,

selecting a spreading set based on said first subset of data bits, said spreading set consisting of one or more of said multiple spreading sequences;

encoding said second subset of data bits, each bit of said second subset of data bits being encoded with a spreading sequences selected from said spreading set; and

transmitting said second subset of data bits.

38. The method of claim 37, further comprising the steps of:

receiving said second subset of data bits;

detecting the spreading set consisting of the one or more of the multiple spreading sequences; and

reconstructing said set of data bits to be communicated based on said second subset of data bits and said detected spreading set.

39. A method for communicating a plurality of data values using multiple spreading sequences, comprising the steps of:

selecting at least one of the multiple spreading sequences based on at least one data value included in the plurality of data values;

applying the at least one of the multiple spreading sequences to other of the plurality of data values so as to directly encode the other of the plurality of data values; and

transmitting the other of the plurality of data values encoded with the at least one of the multiple spreading sequences.

40. The method of claim 39, further comprising the steps of:

receiving the other of the plurality of data values encoded with the at least one of the multiple spreading sequences; and

reconstructing the plurality of data values based at least in part on the other of the plurality of data values received and the detected at least one of the multiple spreading sequences.