Transmission and reception of common channel in an unlicensed or shared spectrum
Methods, systems, and apparatuses are described for wireless communications, in which transmission of common information to two or more receivers over unlicensed spectrum may be provided. The common information may be transmitted over a number (e.g., a set) of different carrier frequencies of the unlicensed spectrum. A staggering pattern may be employed to transmit all or a part of the common information across each of the carrier frequencies in the set of carrier frequencies. The detection of the information on one of the carrier frequencies may provide information that may be used to derive the staggering pattern. The duration of the common information transmission on each of the carrier frequencies may be selected such that a clear channel assessment (CCA) to determine availability of the unlicensed spectrum is not required.
1. A method for wireless communications, comprising:
identifying a set of carrier frequencies for transmission of common information to be received at a plurality of receivers, wherein the common information comprises at least broadcast channel information and one or more of: synchronization information or paging information; and
determining a staggering pattern for transmitting the common information across each of the carrier frequencies in the set of carrier frequencies, wherein determining the staggering pattern comprises selecting non-overlapping time periods for transmission of the common information on different frequencies of the set of carrier frequencies, and wherein each transmission on the different frequencies of the set of carrier frequencies provides the common information;
wherein the set of carrier frequencies includes at least one anchor frequency and a plurality of flexible carrier frequencies selected from a group of available carrier frequencies;
wherein a transmission bandwidth of the synchronization information is less than an available transmission bandwidth for a respective carrier frequency, and wherein additional information is transmitted using remaining available transmission bandwidth.
2. The method of claim 1 , further comprising:
transmitting the common information over the set of carrier frequencies according to the staggering pattern.
3. The method of claim 1 , wherein the staggering pattern comprises transmission of the synchronization information on each of the carrier frequencies, and transmission of the broadcast or the paging information on a subset of the carrier frequencies.
4. The method of claim 1 , wherein the paging information comprises information identified for a specific user equipment (UE) transmitted during a paging opportunity for the UE, and wherein the paging opportunity is a function of one or more UE identifications, one or more carrier frequencies, or both.
5. The method of claim 1 , wherein the paging information is staggered across two or more of the set of carrier frequencies.
6. The method of claim 1 , wherein a time period for transmission of the common information on each carrier frequency is less than a predetermined time period.
7. The method of claim 1 , wherein the staggering pattern is a predetermined staggering pattern that is determinable upon detection of the common information transmission on one of the set of carrier frequencies.
8. The method of claim 1 , wherein the staggering pattern comprises blanking out a subset of carrier frequencies while at least a portion of the common information is transmitted on at least one of the set of carrier frequencies.
9. A method for wireless communications, comprising:
receiving a common information transmission on a carrier frequency, wherein the common information comprises at least broadcast channel information; and
determining a staggering pattern for transmissions of common information across a set of carrier frequencies based on the received common information transmission, wherein determining the staggering pattern comprises:
searching multiple carrier frequencies in parallel or searching a portion of a bandwidth of each carrier frequency in parallel;
combining signals from different carrier frequencies over time to detect a synchronization signal;
identifying a carrier frequency and a time of the received common information transmission; and
determining non-overlapping time periods for transmission of the common information on different frequencies of the set of carrier frequencies, and wherein each transmission on the different frequencies of the set of carrier frequencies provides the common information;
wherein the staggering information is determined based on the frequency and the time of the received common information transmission.
10. The method of claim 9 , wherein the receiving a common information transmission comprises searching multiple carrier frequencies for the common information transmission.
11. The method of claim 9 , further comprising reporting the staggering pattern to a base station for inter-frequency measurement purposes.
12. The method of claim 9 , wherein the common information transmission comprises signaling indicating the staggering pattern.
13. The method of claim 12 , further comprising performing an inter-frequency measurement using information from the staggering pattern.
14. The method of claim 9 , wherein the common information further comprises one or more of synchronization information or paging information.
15. The method of claim 14 , wherein the staggering pattern comprises synchronization information transmission on each of the carrier frequencies, and transmission of broadcast or the paging information on a subset of the carrier frequencies.
16. The method of claim 14 , wherein the paging information comprises information identified for a specific user equipment (UE) transmitted during a paging opportunity for the UE, and wherein the paging opportunity is a function of one or more UE identifications, one or more carrier frequencies, or both.
17. The method of claim 9 , wherein the set of carrier frequencies includes at least one anchor frequency and a plurality of flexible carrier frequencies selected from a group of available carrier frequencies.
18. An apparatus for wireless communications, comprising:
a processor; and
a memory coupled to the processor; wherein the processor is configured to:
identify a set of carrier frequencies for transmission of common information to be received at a plurality of receivers, wherein the common information comprises at least broadcast channel information and one or more of: synchronization information or paging information; and
determine a staggering pattern for transmitting the common information across each of the carrier frequencies in the set of carrier frequencies, wherein determining the staggering pattern comprises selecting non-overlapping time periods for transmission of the common information on different frequencies of the set of carrier frequencies, and wherein each transmission on the different frequencies of the set of carrier frequencies provides the common information;
wherein the set of carrier frequencies includes at least one anchor frequency and a plurality of flexible carrier frequencies selected from a group of available carrier frequencies;
wherein a transmission bandwidth of the synchronization information is less than an available transmission bandwidth for a respective carrier frequency, and wherein additional information is transmitted using remaining available transmission bandwidth.
19. The apparatus of claim 18 , wherein the processor is further configured to cause the apparatus to transmit the common information over the set of carrier frequencies according to the staggering pattern.
20. The apparatus of claim 18 wherein the staggering pattern is a predetermined staggering pattern that is determinable upon detection of the common information transmission on one of the set of carrier frequencies.
21. An apparatus for wireless communications, comprising:
a processor;
memory coupled to the processor, wherein the processor is configured to:
receive a common information transmission on a carrier frequency, wherein the common information comprises at least broadcast channel information; and
determine a staggering pattern for transmissions of common information across a set of carrier frequencies based on the received common information transmission, wherein determining the staggering pattern comprises:
searching multiple carrier frequencies in parallel or searching a portion of a bandwidth of each carrier frequency in parallel;
combining signals from different carrier frequencies over time to detect a synchronization signal;
identifying a carrier frequency and a time of the received common information transmission; and
determining non-overlapping time periods for transmission of the common information on different frequencies of the set of carrier frequencies, and wherein each transmission on the different frequencies of the set of carrier frequencies provides the common information;
wherein the staggering information is determined based on the frequency and the time of the received common information transmission.
22. The apparatus of claim 21 wherein the staggering pattern is a predetermined staggering pattern that is determinable upon detection of the common information transmission on one of the set of carrier frequencies.