MC-CDMA multiplexing in an orthogonal uplink

• US 20060133522A1
• Filed: 12/22/2004
• Published: 06/22/2006
• Est. Priority Date: 12/22/2004
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Agrawal, Avneesh, Sutivong, Arak
• Granted Patent: US 8,831,115 B2
• Time in Patent Office: Days
• 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 of wireless multi-carrier communications, comprising:

dividing sub-carriers on an uplink into non-overlapping groups;

allocating at least one time-frequency block, each time-frequency block having a hopping duration and a non-overlapped group;

assigning a different set of orthogonal codes to each user;

spreading symbols of each user over the allocated at least one time-frequency block, wherein the symbols of each user are spread using the different set of orthogonal codes assigned to each user;

mapping each spread symbol to a modulation symbol in the at least one time-frequency block;

generating an orthogonal waveform based on the mapped symbols; and

transmitting the orthogonal waveform.

2. The method of claim 1, wherein dividing sub-carriers further comprises dividing contiguous sub-carriers into a non-overlapping group.

3. The method of claim 1, wherein generating an orthogonal waveform comprises generating an orthogonal frequency division multiple (OFDM) waveform, and wherein transmitting the orthogonal waveform comprises transmitting an OFDM waverform.

4. The method of claim 1, wherein generating an orthogonal waveform comprises generating an orthogonal frequency division multiple access (OFDMA) waveform, and wherein transmitting the orthogonal waveform comprises transmitting an OFDMA waverform.

5. The method of claim 1, wherein the non-overlapped groups hop independently.

6. The method of claim 1, wherein spreading symbols comprises spreading pilot symbols.

7. The method of claim 1, wherein spreading symbols comprises spreading ACK/NACK symbols.

8. The method of claim 1, wherein spreading symbols comprises spreading CQI symbols.

9. The method of claim 1, wherein spreading symbols comprises spreading Request symbols.

10. The method of claim 1, wherein the orthogonal codes are Walsh codes.

11. The method of claim 1, wherein the orthogonal codes are Gold codes.

12. An apparatus for wireless multi-carrier communications, comprising:

means for dividing sub-carriers on an uplink into non-overlapping groups;

means for allocating at least one time-frequency block, each time-frequency block having a hopping duration and a non-overlapped group;

means for assigning a different set of orthogonal codes to each user;

means for spreading symbols of each user over the allocated at least one time-frequency block, wherein the symbols of each user are spread using the different set of orthogonal codes assigned to each user;

means for mapping each spread symbol to a modulation symbol in the at least one time-frequency block;

means for generating an orthogonal waveform based on the mapped symbols; and

means for transmitting the orthogonal waveform.

13. An apparatus for wireless multi-carrier communications, comprising:

a controller operative to;

divide sub-carriers on an uplink into non-overlapping groups,

allocate at least one time-frequency block, each time-frequency block having a hopping duration and a non-overlapped group; and

assign a different set of orthogonal codes to each user;

a processor operative to;

spread symbols of each user over the allocated at least one time-frequency block, wherein the symbols of each user are spread using the different set of orthogonal codes assigned to each user; and

map each symbol to a modulation symbol in the at least one time-frequency block; and

a transmitter operative to;

generate an orthogonal waveform based on the mapped symbols; and

transmit the orthogonal waveform.

14. A receiver in a wireless multi-carrier communications system, comprising:

an antenna for receiving an orthogonal waveform;

a demodulator for demodulating the orthogonal waveform, thereby creating spread symbols;

a processor for determining a time-frequency block from the spread symbols; and

a de-spreader for de-spreading the spread symbols in the time-frequency block using an orthogonal code for a user.

15. A readable media embodying a method for wireless multi-carrier communications, the method comprising:

dividing sub-carriers on an uplink into non-overlapping groups;

allocating at least one time-frequency block, each time-frequency block having a hopping duration and a non-overlapped group;

assigning a different set of orthogonal codes to each user;

spreading symbols of each user over the allocated at least one time-frequency block, wherein the symbols of each user are spread using the different set of orthogonal codes assigned to each user;

mapping each spread symbol to a modulation symbol in the at least one time-frequency block;

generating an orthogonal waveform based on the mapped symbols; and

transmitting the orthogonal waveform.