Wireless communications over unlicensed radio frequency spectrum
Techniques for transmitting and receiving wireless communications over an unlicensed radio frequency spectrum band are disclosed, including techniques for transmitting and receiving system information blocks over the unlicensed radio frequency spectrum band, techniques for gaining access to the unlicensed radio frequency spectrum band by performing extended clear channel assessments (ECCAs), techniques for transmitting and receiving synchronization signals and reference signals over the unlicensed radio frequency spectrum band, techniques for identifying starting times of downlink transmissions over the unlicensed radio frequency spectrum band, techniques for transmitting and receiving clear channel assessment (CCA)-exempt transmissions over the unlicensed radio frequency spectrum band, techniques for performing random access over the unlicensed radio frequency spectrum band, and techniques for dynamically modifying a transmission mode over the unlicensed radio frequency spectrum band.
1. A method of wireless communication, comprising:
transmitting at least one system information block (SIB), wherein the SIB comprises a Multiple Input Multiple Output (MIMO) parameter and a modulation parameter associated with a communication link over an unlicensed radio frequency spectrum band; and
receiving a transmission over the unlicensed radio frequency spectrum band according to a selected transmission mode based at least on the MIMO parameter and the modulation parameter, wherein the selected transmission mode comprises an orthogonal frequency division multiplexing (OFDM) transmission mode when the MIMO parameter indicates that the communication link supports MIMO transmissions and the selected transmission mode comprises a single-carrier frequency division multiple access (SC-FDMA) transmission mode when the modulation parameter for the communication link is less than or equal to a threshold.
2. The method of claim 1 , wherein the modulation parameter is a modulation and coding scheme (MCS) parameter.
3. The method of claim 1 , wherein the receiving comprises receiving an uplink transmission and the selected transmission mode comprises an uplink transmission mode of the communication link.
4. The method of claim 3 , wherein the uplink transmission mode of the communication link matches a downlink transmission mode of the communication link.
5. The method of claim 1 , wherein the receiving comprises receiving over a plurality of interlaced resource blocks.
6. The method of claim 1 , wherein the selected transmission mode comprises the OFDM transmission mode, and wherein receiving comprises receiving a demodulation reference signal for the communication link according to a subset of resource elements of one or more symbols of one or more resource blocks.
7. The method of claim 6 , wherein, for the OFDM transmission mode, the receiving comprises receiving data in resource elements of the one or more symbols other than the subset of resource elements.
8. The method of claim 1 , wherein the selected transmission mode comprises the SC-FDMA transmission mode, the receiving comprises receiving a demodulation reference signal for the communication link using each resource element of one or more symbols of one or more resource blocks.
9. An apparatus for wireless communication, comprising:
a processor;
memory in electronic communication with the processor; and
instructions stored in the memory, wherein the instructions are executable by the processor to:
transmit at least one system information block (SIB), wherein the SIB comprises a Multiple Input Multiple Output (MIMO) parameter and a modulation parameter associated with a communication link over an unlicensed radio frequency spectrum band; and
receive a transmission over the unlicensed radio frequency spectrum band according to a selected transmission mode based at least on the MIMO parameter and the modulation parameter, wherein the selected transmission mode comprises an orthogonal frequency division multiplexing (OFDM) transmission mode when the MIMO parameter indicates that the communication link supports MIMO transmissions and the selected transmission mode comprises a single-carrier frequency division multiple access (SC-FDMA) transmission mode when the modulation parameter for the communication link is less than or equal to a threshold.
10. The apparatus of claim 9 , wherein the modulation parameter is a modulation and coding scheme (MCS) parameter.
11. The apparatus of claim 9 , wherein receive comprises receive an uplink transmission and the selected transmission mode comprises an uplink transmission mode of the communication link.
12. The apparatus of claim 11 , wherein the uplink transmission mode of the communication link matches a downlink transmission mode of the communication link.
13. The apparatus of claim 9 , wherein receive comprises receive over a plurality of interlaced resource blocks.
14. The apparatus of claim 9 , wherein the selected transmission mode comprises the OFDM transmission mode, and wherein receive comprises receive a demodulation reference signal for the communication link according to a subset of resource elements of one or more symbols of one or more resource blocks.
15. The apparatus of claim 14 , wherein, for the OFDM transmission mode, receive comprises receive data in resource elements of the one or more symbols other than the subset of resource elements.
16. The apparatus of claim 9 , wherein the selected transmission mode comprises the SC-FDMA transmission mode, and wherein receive comprises receive a demodulation reference signal for the communication link using each resource element of one or more symbols of one or more resource blocks.
17. A non-transitory computer-readable medium storing code for wireless communication, code comprising instructions executable to:
transmit at least one system information block (SIB), wherein the SIB comprises a Multiple Input Multiple Output (MIMO) parameter and a modulation parameter associated with a communication link over an unlicensed radio frequency spectrum band; and
receive a transmission over the unlicensed radio frequency spectrum band according to a selected transmission mode based at least on the MIMO parameter and the modulation parameter, wherein the selected transmission mode comprises an orthogonal frequency division multiplexing (OFDM) transmission mode when the MIMO parameter indicates that the communication link supports MIMO transmissions and the selected transmission mode comprises a single-carrier frequency division multiple access (SC-FDMA) transmission mode when the modulation parameter for the communication link is less than or equal to a threshold.
18. The non-transitory computer-readable medium of claim 17 , wherein the modulation parameter is a modulation and coding scheme (MCS) parameter.
19. The non-transitory computer-readable medium of claim 17 , wherein the instructions executable to receive comprise instructions executable to receive an uplink transmission and the selected transmission mode comprises an uplink transmission mode of the communication link.
20. The non-transitory computer-readable medium of claim 19 , wherein the uplink transmission mode of the communication link matches a downlink transmission mode of the communication link.
21. The non-transitory computer-readable medium of claim 17 , wherein the instructions executable to receive comprise instructions executable to receive over a plurality of interlaced resource blocks.
22. The non-transitory computer-readable medium of claim 17 , wherein the selected transmission mode comprises the OFDM transmission mode, and wherein the instructions executable to receive comprise instructions executable to receive a demodulation reference signal for the communication link using a subset of resource elements of one or more symbols of one or more resource blocks.
23. The non-transitory computer-readable medium of claim 22 , wherein, for the OFDM transmission mode, the instructions executable to receive comprise instructions executable to receive data in resource elements of the one or more symbols other than the subset of resource elements.
24. The non-transitory computer-readable medium of claim 17 , wherein the selected transmission mode comprises the SC-FDMA transmission mode, the instructions executable to receive comprise instructions executable to receive a demodulation reference signal for the communication link using each resource element of one or more symbols of one or more resource blocks.