MC-CDMA multiplexing in an orthogonal uplink

• US 8,831,115 B2
• Filed: 12/22/2004
• Issued: 09/09/2014
• Est. Priority Date: 12/22/2004
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Sutivong, Arak, Agrawal, Avneesh
• Primary Examiner(s): TSE, YOUNG TOI
• Application Number:
  US11/022,145
• Publication Number:
  US 20060133522A1
• Time in Patent Office: 3,548 Days
• Field of Search: 375/132, 375/133, 375/135, 375/136, 375/260, 370208-210
• 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 a wireless multi-carrier communications system, comprising:

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

allocating a time-frequency block, wherein the time-frequency block has a hopping duration and a non-overlapped group, and wherein each non-overlapped group hops independently of other non-overlapped groups;

spreading symbols transmitted by a plurality of user terminals over the time-frequency block on the uplink, the plurality of user terminals comprising a first user terminal and a second user terminal, wherein the symbols transmitted by the first user terminal are spread using a first set of orthogonal codes differing from a second set of orthogonal codes used to spread the symbols transmitted by the second user terminal;

mapping each spread symbol to a modulation symbol in the time-frequency block, each spread symbol comprising one of the symbols transmitted by the plurality of user terminals spread over the time-frequency block;

generating an orthogonal waveform based on the mapped symbols; and

transmitting the mapped symbols on the uplink.

2. The method of claim 1, wherein dividing the sub-carriers comprises dividing contiguous sub-carriers into one non-overlapped group.

3. The method of claim 1, further comprising generating an orthogonal frequency division multiple (OFDM) waveform based on the mapped symbols, and wherein transmitting the mapped symbols comprises transmitting the OFDM waveform.

4. The method of claim 1, further comprising generating an orthogonal frequency division multiple access (OFDMA) waveform based on the mapped symbols, and wherein transmitting the mapped symbols comprises transmitting the OFDMA waveform.

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

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

7. The method of claim 1, wherein spreading the symbols comprises spreading CQI (Channel Quality Indicator) symbols.

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

9. The method of claim 1, wherein the first set of orthogonal codes and the second set of orthogonal codes are Walsh codes.

10. The method of claim 1, wherein the first set of orthogonal codes and the second set of orthogonal codes are Gold codes.

11. An apparatus for a wireless multi-carrier communications system, comprising:

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

means for allocating a time-frequency block, wherein the time-frequency block has a hopping duration and a non-overlapped group, and wherein each non-overlapped group hops independently of other non-overlapped groups;

means for spreading symbols transmitted by a plurality of user terminals over the time-frequency block on the uplink, the plurality of user terminals comprising a first user terminal and a second user terminal, wherein the symbols transmitted by the first user terminal are spread using a first set of orthogonal codes differing from a second set of orthogonal codes used to spread the symbols transmitted by the second user terminal;

means for mapping each spread symbol to a modulation symbol in the time-frequency block, each spread symbol comprising one of the symbols transmitted by the plurality of user terminals spread over the time-frequency block;

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

means for transmitting the mapped symbols on the uplink.

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

a controller operative to;

divide sub-carriers on an uplink into non-overlapped groups; and

allocate at least one time-frequency block, wherein the at least one time-frequency block has a hopping duration and a non-overlapped group, and wherein each non-overlapped group hops independently of other non-overlapped groups;

a processor operative to;

spread symbols transmitted by a plurality of user terminals over the time-frequency block on the uplink, the plurality of user terminals comprising a first user terminal and a second user terminal, wherein the symbols transmitted by the first user terminal are spread using a first set of orthogonal codes differing from a second set of orthogonal codes used to spread the symbols transmitted by the second user terminal; and

map each spread symbol to a modulation symbol in the time-frequency block, each spread symbol comprising one of the symbols transmitted by the plurality of user terminals spread over the time-frequency block; and

a transmitter operative to;

generate an orthogonal waveform based on the mapped symbols; and

transmit the mapped symbols on the uplink.

13. A receiver of a wireless multi-carrier communications system, wherein a time-frequency block is allocated, the time-frequency block having a hopping duration and a non-overlapped group, the receiver comprising:

an antenna for receiving an orthogonal waveform, the orthogonal waveform comprising symbols transmitted by a plurality of user terminals on an uplink, the plurality of user terminals comprising a first user terminal and a second user terminal, wherein the symbols transmitted by the plurality of users are spread over the time-frequency block on the uplink using a first set of orthogonal codes assigned to the first user terminal differing from a second set of orthogonal codes assigned to the second user terminal;

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

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

a de-spreader for de-spreading the spread symbols transmitted on the uplink in the received time-frequency block using the first set of orthogonal codes assigned to the first user terminal.

14. A non-transitory computer readable medium embodying code executable by a processor for implementing a method for a wireless multi-carrier communications system, the method comprising:

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

allocating a time-frequency block, wherein the time-frequency block has a hopping duration and a non-overlapped group, and wherein each non-overlapped group hops independently of other non-overlapped groups;

spreading symbols transmitted by a plurality of user terminals over the time-frequency block on the uplink, the plurality of user terminals comprising a first user terminal and a second user terminal, wherein the symbols transmitted by the first user terminal are spread using a first set of orthogonal codes differing from a second set of orthogonal codes used to spread the symbols transmitted by the second user terminal;

mapping each spread symbol to a modulation symbol in the time-frequency block, each spread symbol comprising one of the symbols transmitted by the plurality of user terminals spread over the time-frequency block;

generating an orthogonal waveform based on the mapped symbols; and

transmitting the mapped symbols on the uplink.