MC-CDMA multiplexing in an orthogonal uplink

• US 8,817,897 B2
• Filed: 09/23/2010
• Issued: 08/26/2014
• Est. Priority Date: 12/22/2004
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Sutivong, Arak, Agrawal, Aveneesh
• Primary Examiner(s): TSE, YOUNG TOI
• Application Number:
  US12/889,131
• Publication Number:
  US 20110064039A1
• Time in Patent Office: 1,433 Days
• Field of Search: 375/132, 375/133, 375/136, 375/144, 375/148, 375/260, 375/267, 375/135, 375/138, 375/142, 375/146, 375/147, 375/150, 375/262, 375/265, 375/343, 370208-210, 370/335, 370/342
• US Class Current: 375/260
• CPC Class Codes: H04B 1/692 Hybrid techniques using combinations of two or more spread spectrum techniques
• CPC Class Codes: H04B 1/713 using frequency hopping
• CPC Class Codes: H04J 13/18 Allocation of orthogonal codes
• CPC Class Codes: H04L 5/0021 in which codes are applied as a frequency-domain sequences, e.g. MC-CDMA

Abstract

Techniques are provided to support multi-carrier code division multiple access (MC-CDMA) in an orthogonal uplink of a wireless communication system. A method of wireless multi-carrier communications comprises dividing sub-carriers on an uplink into non-overlapping groups, allocating a time-frequency block including a hopping duration and a non-overlapped group, respectively, assigning a different set of orthogonal codes to each user, spreading data (or pilot) symbols of each user over the allocated time-frequency block, wherein the data (or pilot) symbols of each user are spread using the different set of orthogonal codes assigned to each user, mapping each data (or pilot) symbol to a modulation symbol in the time-frequency block, generating an orthogonal waveform based on the mapped symbols, and transmitting the orthogonal waveform.

Claims

1. A method for determining estimates of wireless transmissions received over a plurality of sub-carriers on an uplink, the method comprising:

dividing the plurality of sub-carriers on the uplink into a plurality of non-overlapping groups of sub-carriers;

assigning multiple user devices to one time frequency block of one non-overlapping group of one uplink sub-carrier;

receiving transmissions from one user device, the one user device configured to hop between frequencies over time within the one non-overlapping group of the one uplink sub-carrier; and

estimating channels from consecutive sub-carriers within the one non-overlapping group using pilot symbols.

2. The method of claim 1, wherein the receiving comprises receiving transmissions from the multiple user devices assigned different sets of orthogonal codes and configured to hop between frequencies over time within multiple non-overlapping groups of multiple sub-carriers.

3. The method of claim 2, wherein the estimating the channels comprises estimating channels from consecutive sub-carriers within the multiple non-overlapping groups of multiple sub-carriers using common pilot symbols.

4. The method of claim 3, wherein the dividing and estimating enable the multiple user devices to share a single time-frequency allocation over the plurality of sub-carriers.

5. The method of claim 1, wherein the assigning the multiple user devices comprises multiplexing user data across different user devices from among the multiple user devices.

6. The method of claim 1, wherein the assigning the multiple user devices comprises multiplexing user data across different signals from the one user device.

7. The method of claim 1, further comprising:

assigning each user device among the multiple user devices a different set of orthogonal codes;

wherein the one user device is configured to spread symbols between frequencies over time using one set of orthogonal codes.

8. An apparatus configured to determine estimates of wireless transmissions received over a plurality of sub-carriers on an uplink, comprising:

a controller configured to divide the plurality of sub-carriers on the uplink into a plurality of non-overlapping groups of sub-carriers and assign multiple user devices to one time frequency block of one non-overlapping group of one uplink sub-carrier;

a receiver configured to receive transmissions from one user device, the one user device configured to hop between frequencies over time within the one non-overlapping group of the one uplink sub-carrier; and

a demodulator configured to estimate channels from consecutive sub-carriers within the one non-overlapping group using pilot symbols.

9. The apparatus of claim 8, wherein the receiver is configured to receive the wireless transmissions from the multiple user devices assigned different sets of orthogonal codes and configured to hop between frequencies over time within multiple non-overlapping groups of multiple sub-carriers.

10. The apparatus of claim 9, wherein the demodulator estimates the channels from consecutive sub-carriers within the multiple non-overlapping groups of multiple sub-carriers using common pilot symbols.

11. The apparatus of claim 8, wherein the demodulator is configured to multiplex received signals across different user devices from among the multiple user devices.

12. The apparatus of claim 11, wherein the controller, the receiver, and the modulator collectively enable the multiple user devices to share a single time-frequency allocation over the plurality of sub-carriers.

13. The apparatus of claim 8, wherein the demodulator is configured to multiplex across different signals from the one user device.

14. The apparatus of claim 8, wherein each user device is assigned a different set of orthogonal codes, the one user device is configured to spread symbols between frequencies over time using one set of orthogonal codes, and the demodulator is configured to estimate the channels based on symbols received that have been spread using multiple sets of orthogonal codes.

15. An apparatus configured to receive and estimate wireless transmissions from a plurality of user devices over a plurality of sub-carriers on an uplink, comprising:

means for dividing the plurality of sub-carriers into a plurality of non-overlapping groups of sub-carriers on the uplink;

means for assigning multiple user devices to one time frequency block of one non-overlapping group of one uplink sub-carrier;

means for receiving transmissions from one user device, the one user device configured to hop between frequencies over time within the one non-overlapping group of the one uplink sub-carrier; and

means for estimating channels from consecutive sub-carriers within the one non- overlapping group using pilot symbols.

16. The apparatus of claim 15, wherein the means for receiving comprise means for receiving transmissions from the multiple user devices assigned different sets of orthogonal codes and configured to hop between frequencies over time.

17. The apparatus of claim 16, wherein the means for estimating the channels comprises means for estimating the channels from consecutive sub-carriers within the multiple non-overlapping groups of multiple sub-carriers using common pilot symbols.

18. A non-transitory computer readable medium embodying code executable by a processor for implementing a method for determining estimates of wireless transmissions received at a base station from a plurality of user devices, the wireless transmissions between the user devices and the base station occurring over a plurality of sub-carriers on an uplink, the method comprising:

dividing the plurality of sub-carriers into a plurality of non-overlapping groups of sub-carriers on the uplink;

assigning the multiple user devices to one time frequency block of one non-overlapping group of one uplink sub-carrier;

receiving transmissions from one user device, the one configured to hop between frequencies over time within the one non-overlapping group of the one uplink sub-carrier; and

estimating channels from consecutive sub-carriers within the one non-overlapping group using pilot symbols.

19. The non-transitory computer readable medium of claim 18, wherein the receiving comprises receiving transmissions from the multiple user devices configured to hop between frequencies over time within multiple non-overlapping groups of multiple sub-carriers.

20. The non-transitory computer readable medium of claim 19, wherein the estimating the channels comprises estimating channels from consecutive sub-carriers within the multiple non-overlapping groups of multiple sub-carriers using common pilot symbols.

21. An apparatus configured to determine estimates of wireless transmissions received on an uplink over a plurality of sub-carriers, comprising:

a receiver configured to receive the wireless transmissions on the uplink and provide a stream of received chips;

a receiver pilot processor configured to receive the stream of received chips and recover data chips derived from the wireless transmissions on the uplink; and

a demodulator configured to receive and coherently demodulate the recovered data chips using channel response estimates to obtain recovered data symbols;

wherein the wireless transmissions comprise one time-frequency block comprising transmissions received from multiple user devices configured to hop between frequencies over time within multiple non-overlapping groups of multiple sub-carriers on the uplink and wherein the demodulator is further configured to estimate channels from consecutive sub-carriers within the multiple non-overlapping groups of multiple sub-carriers using pilot symbols.

22. The apparatus of claim 21, wherein the demodulator is further configured to multiplex received signals across different user devices from among the multiple user devices.

23. The apparatus of claim 21, wherein the demodulator is further configured to multiplex across different signals from one user device.

24. The apparatus of claim 21, wherein each user device from among the multiple user devices is assigned a different set of orthogonal codes, and each user device from among the multiple user devices is configured to spread symbols between frequencies over time using one set of orthogonal codes, and the demodulator is further configured to estimate channels based on symbols received that have been spread using multiple sets of orthogonal codes.

25. The apparatus of claim 21, wherein the receiver, the receiver pilot processor, and the demodulator collectively enable the multiple user devices to share a single time-frequency allocation within the multiple sub-carriers.

26. A method for determining estimates of wireless transmissions received on an uplink over a plurality of sub-carriers, comprising:

receiving the wireless transmissions on the uplink and providing a stream of received chips based on the wireless transmissions;

receiving the stream of received chips and recovering data chips derived from the wireless transmissions; and

coherently demodulating the recovered data chips using channel response estimates to obtain recovered data symbols;

wherein the wireless transmissions comprise one time-frequency block comprising transmissions received from multiple user devices configured to hop between frequencies over time within multiple non-overlapping groups of multiple sub-carriers on the uplink and wherein the coherently demodulating comprises estimating channels from consecutive sub-carriers within the multiple non-overlapping groups of multiple sub-carriers using pilot symbols.

27. The method of claim 26, wherein the coherently demodulating comprises multiplexing received signals across different user devices from among the multiple user devices.

28. The method of claim 26, wherein the coherently demodulating comprises multiplexing across different signals from one user device.

29. The method of claim 26, wherein each user device from among the multiple user devices is assigned a different set of orthogonal codes, and each user device from among the multiple user devices is configured to spread symbols between frequencies over time using one set of orthogonal codes, and the coherently demodulating comprises estimating channels based on symbols received that have been spread using multiple sets of orthogonal codes.

30. The method of claim 26, wherein the receiving the wireless transmissions, the receiving the stream of received chips, and the coherently demodulating collectively enable the multiple user devices to share a single time-frequency allocation within the multiple sub-carriers.

31. An apparatus configured to determine estimates of wireless transmissions received on the uplink over a plurality of sub-carriers, comprising:

means for receiving the wireless transmissions on the uplink and providing a stream of received chips based on the wireless transmissions;

means for receiving the stream of received chips and recovering data chips derived from the wireless transmissions; and

means for coherently demodulating the recovered data chips using channel response estimates to obtain recovered data symbols;

wherein the wireless transmissions comprise one time-frequency block comprising transmissions received from multiple user devices configured to hop between frequencies over time within multiple non-overlapping groups of multiple sub-carriers on the uplink and wherein the coherently demodulating comprises estimating channels from consecutive sub-carriers within the multiple non-overlapping groups of multiple sub-carriers using pilot symbols.

32. The apparatus of claim 31, wherein the means for coherently demodulating comprise means for multiplexing received signals across different user devices from among the multiple user devices.

33. The apparatus of claim 31, wherein the means for coherently demodulating comprise means for multiplexing across different signals from one user device.

34. The apparatus of claim 31, wherein each user device from among the multiple user devices is assigned a different set of orthogonal codes, and each user device from among the multiple user devices is configured to spread symbols between frequencies over time using one set of orthogonal codes, and the means for coherently demodulating comprises means for estimating channels based on symbols received that have been spread using multiple sets of orthogonal codes.

35. The apparatus of claim 31, wherein the means for receiving the wireless transmissions, the means for receiving the stream of received chips, and the means for coherently modulating collectively enable the multiple user devices to share a single time-frequency allocation within the multiple sub-carriers.

36. A non-transitory computer readable medium embodying code executable by a processor for implementing a method for determining estimates of wireless transmissions received on an uplink over a plurality of sub-carriers, comprising:

receiving the wireless transmissions on the uplink and providing a stream of received chips based on the wireless transmissions;

receiving the stream of received chips and recovering data chips derived from the wireless transmissions; and

coherently demodulating the recovered data chips using channel response estimates to obtain recovered data symbols;

wherein the wireless transmissions comprise one time-frequency block comprising transmissions received from multiple user devices configured to hop between frequencies over time within multiple non-overlapping groups of multiple sub-carriers on the uplink and wherein the coherently demodulating comprises estimating channels from consecutive sub-carriers using common pilot symbols.

37. The non-transitory computer readable medium of claim 36, wherein the coherently demodulating comprises multiplexing received signals across different user devices from among the multiple user devices.

38. The non-transitory computer readable medium of claim 36, wherein the coherently demodulating comprises multiplexing across different signals from one user device.

39. The non-transitory computer readable medium of claim 36, wherein each user device from among the multiple user devices is assigned a different set of orthogonal codes, and each user device from among the multiple user devices is configured to spread symbols between frequencies over time using one set of orthogonal codes, and the coherently demodulating comprises estimating channels based on symbols received that have been spread using multiple sets of orthogonal codes.

40. The non-transitory computer readable medium of claim 36, wherein the receiving the wireless transmissions, the receiving the stream of received chips, and the coherently demodulating collectively enable the multiple user devices to share a single time-frequency allocation within the multiple sub-carriers.