Reference signal presence detection based license assisted access and reference signal sequence design

1. A user equipment device (UE) comprising:

physical layer circuitry configured to transmit and receive radio frequency electrical signals with one or more nodes of a radio access network, including to:

monitor at least one of a communication channel unlicensed to a long term evolution (LTE) network (LTE-U) or a communication channel of a licensed assisted access (LAA) network; and

detect a reference signal (RS) of a subframe communicated using the at least one communication channel; and

processing circuitry configured to:

measure a channel metric over at least a portion of the subframe that includes the RS; and

process information included in the subframe according to an LTE communication protocol when the measured channel metric satisfies a specified channel metric threshold value,

wherein the processing circuitry includes a RS sequence generator module including a pseudo-random number sequence generator module, wherein the RS sequence generator is configured to generate an RS of an RS sequence using a pseudo-random number sequence determined using physical cell (PCell) information unique to the UE among UEs operating within a specific PCell, and the processing circuitry is further configured to communicate the RS via the at least one communication channel.

2. The UE of claim 1 , wherein the physical layer circuitry is configured to receive the PCell information using the UE and the RS sequence generator module is configured to generate the RS of the RS sequence using the received PCell information.

3. The UE of claim 1 , wherein the PCell information includes at least one of a public land mobile network (PLMN) identity or an evolved cell global identifier (E-CGI), and the RS sequence generator is configured to generate the RS of an RS sequence using the at least one of the PLMN identity information or the E-CGI information.

4. The UE of claim 1 , wherein the RS sequence generator module includes a scrambling module, wherein the scrambling module is configured to scramble a pseudo-random number sequence generated by the pseudo-random number sequence generator module with the PCell information, and wherein the RS sequence module is configured to obtain the RS sequence using the scrambled pseudo random number sequence.

5. The UE of claim 1 , wherein the RS sequence generator module is configured to initialize a pseudo-random sequence generated by the pseudo-random sequence generator module with an initial pseudo-random sequence value modified with the PCell information and obtain the RS sequence using a pseudo-random sequence generated using the modified initial pseudo-random sequence value.

6. The UE of claim 1 , wherein processing circuitry is configured to decode at least one of physical downlink control channel PDCCH information, enhanced physical downlink control channel (ePDCCH) information, or physical downlink shared channel (PDSCH) information using subframe information when the measured channel metric satisfies a specified channel metric threshold value.

7. The UE of claim 1 , wherein processing circuitry is configured to estimate one or more channel characteristics when the measured channel metric satisfies a specified channel metric threshold value, and communicate channel state information (CSI) using the one or more channel characteristics.

8. The UE of claim 1 , wherein the physical layer circuitry is configured to:

communicate with at least one of a network node device or another UE using a frequency band licensed to a long term evolution (LTE) network; and to communicate with an access point device or a network station device using at least one of a frequency band icensed to an LTE network (LTE-U) or a frequency band of a licensed assisted access (LAA) network.

9. The UE of claim 1 , including a plurality of antennas conductively coupled to the physical layer circuitry.

10. A non-transitory computer-readable storage medium that stores instructions for execution by one or more processors of user equipment (UE) to perform operations to configure the UE to:

monitor a communication channel using the UE, wherein the communication channel is at least one of a communication channel unlicensed to a long term evolution (LTE) network (LTE-U) or a communication channel of a licensed assisted access (LAA) network;

detect a reference signal (RS) of a subframe communicated using the communication channel;

measure a channel metric over at least a portion of the subframe that includes the RS;

process information included in the subframe according to an LTE communication protocol when the measured channel metric satisfies a specified channel metric threshold value;

receive PCell information that includes at least one of a public land mobile network (PLMN) identity information or an evolved cell global identifier (E-CGI) information; and

generate an RS of an RS sequence using the at least one of the PLMN identity information or the E-CGI information.

11. The non-transitory computer-readable storage medium of claim 10 , including instructions to perform operations to configure the UE to: initialize a pseudo-random sequence generated by the UE with an initial pseudo-random sequence value modified with the PCell information; obtain the RS sequence using a pseudo-random sequence generated by the UE with the modified initial pseudo-random sequence value; and communicate the RS via the communication channel.

12. The non-transitory computer-readable storage medium of claim 10 , including instructions to perform operations to configure the UE to generate a pseudo-random number sequence using the UE, scramble the generated pseudo random number sequence with the PCell information, and use the scrambled pseudo random number sequence to produce the RS sequence.

13. The non-transitory computer-readable storage medium of claim 10 , including instructions to perform operations to configure the UE to: estimate channel characteristics using the measured channel metric and communicating channel state information (CSI) according to the channel characteristics.

14. An apparatus of a user equipment device (UE) of a cellular network, the apparatus comprising processing circuitry configured to:

measure a channel metric over at least a portion of a subframe communicated by a separate device using at least one of a communication channel unlicensed to a long term evolution (LTE) network (LTE-U) or a communication channel of a licensed assisted access (LAA) network, wherein the channel metric is measured over at least a portion of the subframe that includes a reference signal (RS);

decode at least one of physical downlink control channel PDCCH information, enhanced physical downlink control channel (ePDCCH) information, or physical downlink shared channel (PDSCH) information when the measured channel metric satisfies a specified channel metric threshold value;

generate an RS of an RS sequence as a pseudo-random number sequence determined using physical cell (PCell) information received via the cellular network; and

initiate communication of the RS via the at least one communication channel.

15. The apparatus of claim 14 , including a transceiver circuit configured to transmit and receive radio frequency electrical signals via the cellular network and the at least one communication channel unlicensed to a long term evolution (LTE) network (LTE-U) or communication channel of a licensed assisted access (LAA) network.

16. The apparatus of claim 14 , wherein the processing circuitry is configured to: initialize a pseudo-random sequence generated by the UE with an initial pseudo-random sequence value modified with the PCell information; obtain the RS of the RS sequence using a pseudo-random sequence generated by the UE with the modified initial pseudo-random sequence value; and communicate the RS via the communication channel.

17. The apparatus of claim 14 , wherein the processing circuitry is configured to: generate a pseudo-random number sequence, scramble the generated pseudo random number sequence with the PCell information, and use the scrambled pseudo random number sequence to produce the RS of the RS sequence.

18. The apparatus of claim 14 , wherein the processing circuitry is configured to: initialize a pseudo-random sequence generated by the UE with an initial pseudo-random sequence value modified using PCell information that includes at least one of the public land mobile network (PLMN) identity or the evolved cell global identifier (E-CGI); obtain the RS of the RS sequence using a pseudo-random sequence generated by the UE with the modified initial pseudo-random sequence value; and communicate the RS via the communication channel.

19. The apparatus of claim 14 , wherein the processing circuitry is configured to receive PCell information that includes at least one of the public land mobile network (PLMN) identity or the evolved cell global identifier (E-CGI) and generate the RS of an RS sequence using the at least one of the PLMN identity information or the E-CGI information.

20. The apparatus of claim 14 , wherein the processing circuitry is configured to estimate channel characteristics using the measured channel metric and communicate channel state information (CSI) according to the channel characteristics.