Variable bandwidth OFDM receiver and methods for receiving OFDM signals of different bandwidths
View Patent ↗A variable bandwidth OFDM receiver and methods for receiving OFDM signals of different bandwidths are generally disclosed herein. The variable bandwidth OFDM receiver may be configured to receive signals over wider bandwidths by processing a resource block of subcarriers comprising a greater number of subcarriers, and receive signals over narrower bandwidths by processing a resource block of subcarriers comprising a lesser number of subcarriers. The resource blocks have a number of OFDM symbols in a time dimension to define a time slot, and each wherein the resource block comprises a minimum number of subcarriers for a narrowest bandwidth for a predetermined minimum bandwidth reception and a predetermined maximum number of subcarriers for a maximum bandwidth reception. In some embodiments, the variable bandwidth receiver may operate in accordance with an 3GPP LTE E-UTRAN standard.
1. A wireless communication device comprising:
a variable bandwidth receiver configurable receive OFDM symbols over different bandwidths using multiple antennas;
a transmitter configured to transmit a reference signal; and
antenna selection circuitry to select some of the antennas,
wherein the receiver is arranged to receive OFDM symbols over a wideband channel using the selected antennas by processing two or more sets of subcarriers and arranged to receive OFDM symbols over a subchannel by processing a single set of subcarriers using the selected antennas,
wherein the transmitter is arranged to transmit data using the selected antennas,
wherein two or more of the antennas are selected based on channel conditions determined from the transmitted reference signal, the selected antennas being a subset of the multiple antennas and include less than all of the antennas, and
wherein each set of subcarriers comprise a predetermined number of subcarriers.
2. The wireless communication device of claim 1 wherein to process the two or more sets of subcarriers, the receiver is configured to perform an FFT on time-domain signals corresponding to the symbols received over the two or more sets of subcarriers, and
wherein to process the single set of subcarriers, the receiver is configured to perform an FFT on time-domain signals corresponding to the symbols received over the single set.
3. The wireless communication device of claim 2 wherein the multiple antennas comprise a plurality of spatially diverse antennas, and
wherein the receiver further comprises circuitry to combine signals received through multiple antennas.
4. The wireless communication device of claim 3 wherein the wireless communication device is part of a mobile station.
5. A mobile station having multiple antennas configured for receiving OFDM symbols over different bandwidths, the mobile station configured to:
transmit a reference signal;
select some of the antennas;
receive OFDM symbols over a wideband channel using the selected antennas by processing two or more sets of subcarriers; and
receive OFDM symbols over a subchannel using the selected antennas by processing a single set of subcarriers,
wherein the two or more of the antennas are selected based on channel conditions determined from the transmitted reference signal, the selected antennas being a subset of the multiple antennas,
wherein each set of subcarriers comprise a predetermined number of subcarriers.
6. The mobile station of claim 5 wherein to process the two or more sets of subcarriers, the mobile station is configured to perform an FFT on time-domain signals corresponding to the symbols received over the two or more sets of subcarriers, and
wherein to process the single set of subcarriers, the mobile station is configured to perform an FFT on time-domain signals corresponding to the symbols received over the single set of subcarriers.
7. The mobile station of claim 6 wherein the multiple antennas comprise a plurality of spatially diverse antennas, and
wherein the receiver further comprises circuitry to combine signals received the multiple antennas.
8. A method for variable bandwidth reception performed by a variable bandwidth receiver, the method comprising:
transmitting a reference signal;
selecting some antennas for variable bandwidth reception from a set of multiple antennas;
receiving OFDM symbols over a wideband channel using the selected antennas by processing two or more sets of subcarriers;
receiving OFDM symbols over a subchannel using the selected antennas by processing a single set of subcarriers
wherein the transmitter is arranged to transmit data using the selected antennas,
wherein two or more of the antennas are selected based on channel conditions determined from the transmitted reference signal, the selected antennas being a subset of the multiple antennas and include less than all of the antennas, and
wherein each set of subcarriers comprise a predetermined number of subcarriers.
9. The method of claim 8 wherein processing two or more sets of subcarriers comprises performing an FFT on time-domain signals corresponding to the symbols received over the two or more sets of subcarriers, and
wherein processing the single set of subcarriers comprises performing an FFT on time-domain signals corresponding to the symbols received over the single set of subcarriers.