Detection of time division duplex downlink/uplink configuration
A user equipment (UE) in a cellular telecommunications system is able to detect the uplink/downlink configuration of a detected neighboring cell by receiving a signal from the neighboring cell. A characteristic of the received signal is detected and used as an indicator in a blind detection process to identify one or more downlink slots in the received signal. Known pilot signals in the identified one or more downlink slots can then be used to obtain a signal power measurement of the received signal. The blind detection process is also capable of detecting whether a slot of a neighboring cell's signal is a downlink unicast slot or a Multicast-Broadcast Single Frequency Network slot.
1. A method of operating a user equipment (UE) in a cellular telecommunications system, the method comprising:
receiving a signal from a neighboring cell, wherein the signal comprises a plurality of slots of which some of the plurality of slots are downlink slots and some of the plurality of slots are uplink slots, and wherein a configuration of the downlink and uplink slots is unknown;
detecting a characteristic of the received signal;
using the detected characteristic as an indicator in a blind detection process that relies on characteristic differences between uplink and downlink slots to identify the configuration of the downlink and uplink slots in the received signal; and
using the identified configuration of the downlink and uplink slots to obtain known pilot signals from one or more downlink slots of the received signal and using the known pilot signals to obtain a signal power measurement of the received signal,
wherein:
the detected characteristic is a detected information content of resource elements of the received signal known to be reference symbol resource elements in a downlink subframe, wherein each resource element is defined by subcarrier frequency and time of occurrence; and
the blind detection process comprises correlating the detected information content with information content of one or more known reference symbols.
2. A method of operating a user equipment (UE) in a cellular telecommunications system, the method comprising:
receiving a signal from a neighboring cell, wherein the signal comprises a plurality of slots of which some of the plurality of slots are downlink slots and some of the plurality of slots are uplink slots, and wherein a configuration of the downlink and uplink slots is unknown;
detecting a characteristic of the received signal;
using the detected characteristic as an indicator in a blind detection process that relies on characteristic differences between uplink and downlink slots to identify the configuration of the downlink and uplink slots in the received signal; and
using the identified configuration of the downlink and uplink slots to obtain known pilot signals from one or more downlink slots of the received signal and using the known pilot signals to obtain a signal power measurement of the received signal,
wherein:
the detected characteristic is a detected automatic gain control setting used to receive the received signal; and
the blind detection process comprises comparing the detected automatic gain control setting with an automatic gain control setting of a known downlink slot.
3. A method of operating a user equipment (UE) in a cellular telecommunications system having a radio interface that comprises a plurality of downlink slots of which some of the plurality of downlink slots are downlink unicast slots and some of the plurality of downlink slots are Multicast-Broadcast Single Frequency Network slots, the method comprising:
receiving a signal from a neighboring cell during one or more of the plurality of downlink slots;
detecting a characteristic of the received signal;
using the detected characteristic as an indicator in a blind detection process that relies on characteristic differences between the downlink unicast slots and the Multicast-Broadcast Single Frequency Network slots to identify one or more of the downlink unicast slots that may be present in the one or more of the downlink slots; and
in response to the one or more identified downlink unicast slots being identified in the one or more of the plurality of downlink slots, using known pilot signals in the one or more identified downlink unicast slots to obtain a signal power measurement of the received signal,
wherein:
the detected characteristic is a detected information content of resource elements of the received signal known to be reference symbol resource elements in a downlink subframe, wherein each resource element is defined by subcarrier frequency and time of occurrence; and
the blind detection process comprises correlating the detected information content with information content of one or more known reference symbols.
4. A method of operating a user equipment (UE) in a cellular telecommunications system having a radio interface that comprises a plurality of downlink slots of which some of the plurality of downlink slots are downlink unicast slots and some of the plurality of downlink slots are Multicast-Broadcast Single Frequency Network slots, the method comprising:
receiving a signal from a neighboring cell during one or more of the plurality of downlink slots;
detecting a characteristic of the received signal;
using the detected characteristic as an indicator in a blind detection process that relies on characteristic differences between the downlink unicast slots and the Multicast-Broadcast Single Frequency Network slots to identify one or more of the downlink unicast slots that may be present in the one or more of the downlink slots; and
in response to the one or more identified downlink unicast slots being identified in the one or more of the plurality of downlink slots, using known pilot signals in the one or more identified downlink unicast slots to obtain a signal power measurement of the received signal,
wherein:
the detected characteristic is a detected automatic gain control setting used to receive the received signal; and
the blind detection process comprises comparing the detected automatic gain control setting with an automatic gain control setting of a known downlink slot.
5. A user equipment (UE) in a cellular telecommunications system, the user equipment comprising:
logic circuitry configured to receive a signal from a neighboring cell, wherein the signal comprises a plurality of slots of which some of the plurality of slots are downlink slots and some of the plurality of slots are uplink slots, and wherein a configuration of the downlink and uplink slots is unknown;
logic circuitry configured to detect a characteristic of the received signal;
logic circuitry configured to use the detected characteristic as an indicator in a blind detection process that relies on characteristic differences between uplink and downlink slots to identify the configuration of the downlink and uplink slots in the received signal; and
logic circuitry configured to use the identified configuration of the downlink and uplink slots to obtain known pilot signals from one or more downlink slots of the received signal and using the known pilot signals to obtain a signal power measurement of the received signal,
wherein:
the detected characteristic is a detected information content of resource elements of the received signal known to be reference symbol resource elements in a downlink subframe, wherein each resource element is defined by subcarrier frequency and time of occurrence; and
the blind detection process comprises correlating the detected information content with information content of one or more known reference symbols.
6. A user equipment (UE) in a cellular telecommunications system, the user equipment comprising:
logic circuitry configured to receive a signal from a neighboring cell, wherein the signal comprises a plurality of slots of which some of the plurality of slots are downlink slots and some of the plurality of slots are uplink slots, and wherein a configuration of the downlink and uplink slots is unknown;
logic circuitry configured to detect a characteristic of the received signal;
logic circuitry configured to use the detected characteristic as an indicator in a blind detection process that relies on characteristic differences between uplink and downlink slots to identify the configuration of the downlink and uplink slots in the received signal; and
logic circuitry configured to use the identified configuration of the downlink and uplink slots to obtain known pilot signals from one or more downlink slots of the received signal and using the known pilot signals to obtain a signal power measurement of the received signal,
wherein:
the detected characteristic is a detected automatic gain control setting used to receive the received signal; and
the blind detection process comprises comparing the detected automatic gain control setting with an automatic gain control setting of a known downlink slot.
7. A user equipment (UE) in a cellular telecommunications system having a radio interface that comprises a plurality of downlink slots of which some of the plurality of downlink slots are downlink unicast slots and some of the plurality of downlink slots are Multicast-Broadcast Single Frequency Network slots, the user equipment comprising:
logic circuitry configured to receive a signal from a neighboring cell during one or more of the plurality of downlink slots;
logic circuitry configured to detect a characteristic of the received signal;
logic circuitry configured to use the detected characteristic as an indicator in a blind detection process that relies on characteristic differences between the downlink unicast slots and the Multicast-Broadcast Single Frequency Network slots to identify one or more of the downlink unicast slots that may be present in the one or more of the plurality of downlink slots; and
logic circuitry configured to use known pilot signals in the one or more identified downlink unicast slots to obtain a signal power measurement of the received signal in response to the one or more identified downlink unicast slots being identified in the one or more of the plurality of downlink slots,
wherein:
the detected characteristic is a detected information content of resource elements of the received signal known to be reference symbol resource elements in a downlink subframe, wherein each resource element is defined by subcarrier frequency and time of occurrence; and
the blind detection process comprises correlating the detected information content with information content of one or more known reference symbols.
8. A user equipment (UE) in a cellular telecommunications system having a radio interface that comprises a plurality of downlink slots of which some of the plurality of downlink slots are downlink unicast slots and some of the plurality of downlink slots are Multicast-Broadcast Single Frequency Network slots, the user equipment comprising:
logic circuitry configured to receive a signal from a neighboring cell during one or more of the plurality of downlink slots;
logic circuitry configured to detect a characteristic of the received signal;
logic circuitry configured to use the detected characteristic as an indicator in a blind detection process that relies on characteristic differences between the downlink unicast slots and the Multicast-Broadcast Single Frequency Network slots to identify one or more of the downlink unicast slots that may be present in the one or more of the plurality of downlink slots; and
logic circuitry configured to use known pilot signals in the one or more identified downlink unicast slots to obtain a signal power measurement of the received signal in response to the one or more identified downlink unicast slots being identified in the one or more of the plurality of downlink slots,
wherein:
the detected characteristic is a detected automatic gain control setting used to receive the received signal; and
the blind detection process comprises comparing the detected automatic gain control setting with an automatic gain control setting of a known downlink slot.