Hybrid orthogonal frequency division multiple access system and method
View Patent ↗A hybrid orthogonal frequency division multiple access (OFDMA) system including a transmitter and a receiver is disclosed. The transmitter includes a first spread OFDMA subassembly, a first non-spread OFDMA subassembly and a first common subassembly. The first spread OFDMA subassembly spreads input data and maps the spread data to a first group of subcarriers. The first non-spread OFDMA subassembly maps input data to a second group of subcarriers. The first common subassembly transmits the input data mapped to the first and second group of subcarriers using OFDMA. The receiver includes a second spread OFDMA subassembly, a second non-spread OFDMA subassembly and a second common subassembly. The second common subassembly processes received data to recover data mapped to the subcarriers using OFDMA. The second spread OFDMA subassembly recovers the first input data by separating user data in a code domain and the second non-spread OFDMA subassembly recovers the second input data.
1. A wireless transmit/receive unit (WTRU) configured to perform hybrid orthogonal frequency division multiple access (OFDMA) communications comprising:
a receiver configured to receive hybrid OFDMA symbols, where the hybrid OFDMA symbols include multi-user spread input data on a first group of subcarriers and non-spread input data on a second group of subcarriers;
the receiver configured to process the received hybrid OFDMA symbols to recover single-user spread input data from the multi-user spread input data on the first group of subcarriers and the non-spread input data from the second group of subcarriers;
the receiver comprising:
a spread OFDMA subassembly configured to recover single-user input data from the multi-user spread input data by performing code domain user separation; and
a non-spread OFDMA subassembly configured to recover second input data from the non-spread input data.
2. The WTRU of claim 1 wherein the multi-user spread input data is spread in at least one of a time-domain or a frequency domain.
3. The WTRU of claim 1 wherein the multi-user spread input data is spread by repeating the single-user input data at a chip rate.
4. The WTRU of claim 1 wherein the spread OFDMA subassembly is configured to recover common pilots transmitted on the first group of subcarriers.
5. The WTRU of claim 1 wherein the non-spread OFDMA subassembly implements at least one of time-domain hopping or frequency-domain hopping in demapping the second input data from the second group of subcarriers.
6. The WTRU of claim 1 wherein the spread OFDMA subassembly comprises a Rake combiner.
7. The WTRU of claim 1 wherein the spread OFDMA subassembly comprises a time-frequency Rake combiner.
8. The WTRU of claim 1 wherein the receiver comprises multiple antennas.
9. The WTRU of claim 1 configured as a User Equipment (UE).
10. A method for hybrid orthogonal frequency division multiple access (OFDMA) communications in a wireless transmit/receive unit (WTRU), the method comprising:
receiving hybrid OFDMA symbols, where the hybrid OFDMA symbols include multi-user spread input data on a first group of subcarriers and non-spread input data on a second group of subcarriers;
processing the received hybrid OFDMA symbols to recover single-user spread input data from the multi-user spread input data on the first group of subcarriers and the non-spread input data from the second group of subcarriers;
recovering single-user input data from the multi-user spread input data by performing code domain user separation; and
recovering second input data from the non-spread input data.
11. The method of claim 10 wherein the multi-user spread input data is spread in at least one of a time-domain or a frequency domain.
12. The method of claim 10 wherein the multi-user spread input data is spread by repeating the single-user input data at a chip rate.
13. The method of claim 10 further comprising recovering common pilots on the first group of subcarriers.
14. The method of claim 10 wherein at least one of time-domain hopping or frequency-domain hopping is performed in demapping the second input data from the second group of subcarriers.
15. The method of claim 10 further comprising separating the spread input data with a Rake combiner.
16. The method of claim 10 further comprising separating the spread input data within a code domain using a time-frequency Rake combiner.
17. The method of claim 10 performed by a User Equipment (UE).
18. A Node-B configured to perform hybrid orthogonal frequency division multiple access (OFDMA) communications comprising:
a transmitter comprising:
a spread OFDMA subassembly configured to spread multi-user input data to generate multi-user spread input data;
the spread OFDMA subassembly configured to map the multi-user spread input data to a first group of subcarriers;
a non-spread OFDMA subassembly configured to map non-spread input data to a second group of subcarriers; and
the transmitter being configured to transmit the multi-user spread input data and the non-spread input data over the first group of subcarriers and second groups of subcarriers, respectively, as part of hybrid OFDMA symbols transmission.
19. The Node-B of claim 18 wherein the spread OFDMA subassembly spreads the multi-user input data in at least one of a time-domain or a frequency domain.
20. The Node-B of claim 18 wherein the spread OFDMA subassembly spreads the multi-user input data by repeating single-user input data at a chip rate.
21. The Node-B of claim 18 wherein the spread OFDMA subassembly and the non-spread OFDMA subassembly maps the first group of subcarriers and the second group of subcarriers dynamically.
22. The Node-B of claim 18 wherein the spread OFDMA subassembly transmits common pilots on the first group of subcarriers.
23. The Node-B of claim 18 wherein the non-spread OFDMA subassembly implements at least one of time-domain hopping or frequency-domain hopping in mapping the second input data to the second group of subcarriers.
24. The Node-B of claim 18 wherein the transmitter comprises multiple antennas.