A method for wireless communications includes determining a time division duplex (TDD) configuration of a non-serving network. The method also includes detecting interference from the non-serving network based at least in part on the TDD configuration of the non-serving network. The method further includes signaling an eNodeB of the interference based at least in part on the detecting.

BACKGROUND

Aspects of the present disclosure relate generally to wireless communication systems, and more particularly to mitigating interference in a wireless network.

SUMMARY

In one configuration, a method of wireless communication is disclosed. The method includes determining a time division duplex (TDD) configuration of a non-serving network. The method also includes detecting interference from the non-serving network based at least in part on the TDD configuration of the non-serving network. The method further includes signaling an eNodeB of the interference based at least in part on the detecting.

Another configuration discloses an apparatus including means for determining a TDD configuration of a non-serving network. The apparatus also includes means for detecting interference from the non-serving network based at least in part on the TDD configuration of the non-serving network. The apparatus further includes means for signaling an eNodeB of the interference based at least in part on the detecting.

In another configuration, a computer program product for wireless communications in a wireless network having a non-transitory computer-readable medium is disclosed. The computer readable medium has non-transitory program code recorded thereon which, when executed by the processor(s), causes the processor(s) to perform operations of determining a TDD configuration of a non-serving network. The program code also causes the processor(s) to detect interference from the non-serving network based at least in part on the TDD configuration of the non-serving network. The program code also causes the processor(s) to signal an eNodeB of the interference based at least in part on the detecting.

Another configuration discloses a wireless communication device having a memory and at least one processor coupled to the memory. The processor(s) is configured to determine a TDD configuration of a non-serving network. The processor(s) are also configured to detect interference from the non-serving network based at least in part on the TDD configuration of the non-serving network. The processor(s) are further configured to signal an eNodeB of the interference based at least in part on the detecting.

In one configuration, a method of wireless communication is disclosed. The method includes receiving an indication that a UE served by an eNodeB is causing interference with communications of a non-serving network. The method also includes adjusting communications of the UE to reduce the interference.

Another configuration discloses an apparatus including means for receiving an indication that a UE served by an eNodeB is causing interference with communications of a non-serving network. The apparatus also includes means for adjusting communications of the UE to reduce the interference.

In another aspect, a computer program product for wireless communications in a wireless network having a non-transitory computer-readable medium is disclosed. The computer readable medium has non-transitory program code recorded thereon which, when executed by the processor(s), causes the processor(s) to perform operations of receiving an indication that a UE served by an eNodeB is causing interference with communications of a non-serving network. The program code also causes the processor(s) to adjust communications of the UE to reduce the interference.

Another aspect discloses a wireless communication device having a memory and at least one processor coupled to the memory. The processor(s) is configured to receive an indication that a UE served by an eNodeB is causing interference with communications of a non-serving network. The processor(s) is also configured to adjust communications of the UE to reduce the interference.

DETAILED DESCRIPTION

The E-UTRAN includes the evolved Node B (eNodeB)106and other eNodeBs108. The eNodeB106provides user and control plane protocol terminations toward the UE102. The eNodeB106may be connected to the other eNodeBs108via a backhaul (e.g., an X2 interface). The eNodeB106may also be referred to as a base station, a base transceiver station, a radio base station, a radio transceiver, a transceiver function, a basic service set (BSS), an extended service set (ESS), or some other suitable terminology. The eNodeB106provides an access point to the EPC110for a UE102. Examples of UEs102include a cellular phone, a smart phone, a session initiation protocol (SIP) phone, a laptop, a personal digital assistant (PDA), a satellite radio, a global positioning system, a multimedia device, a video device, a digital audio player (e.g., MP3 player), a camera, a game console, or any other similar functioning device. The UE102may also be referred to by those skilled in the art as a mobile station, a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communications device, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handset, a user agent, a mobile client, a client, or some other suitable terminology.

The eNodeB106is connected to the EPC110via, e.g., an S1 interface. The EPC110includes a Mobility Management Entity (MME)112, other MMEs114, a Serving Gateway116, and a Packet Data Network (PDN) Gateway118. The MME112is the control node that processes the signaling between the UE102and the EPC110. Generally, the MME112provides bearer and connection management. All user IP packets are transferred through the Serving Gateway116, which itself is connected to the PDN Gateway118. The PDN Gateway118provides UE IP address allocation as well as other functions. The PDN Gateway118is connected to the Operator's IP Services122. The Operator's IP Services122may include the Internet, the Intranet, an IP Multimedia Subsystem (IMS), and a PS Streaming Service (PSS).

FIG. 2is a diagram illustrating an example of an access network200in an LTE network architecture. In this example, the access network200is divided into a number of cellular regions (cells)202. One or more lower power class eNodeBs208may have cellular regions210that overlap with one or more of the cells202. A lower power class eNodeB208may be a remote radio head (RRH), a femto cell (e.g., home eNodeB (HeNB)), a pico cell, or a micro cell. The macro eNodeBs204are each assigned to a respective cell202and are configured to provide an access point to the EPC110for all the UEs206in the cells202. There is no centralized controller in this example of an access network200, but a centralized controller may be used in alternative configurations. The eNodeBs204are responsible for all radio related functions including radio bearer control, admission control, mobility control, scheduling, security, and connectivity to the serving gateway116.

FIG. 4is a diagram400illustrating an example of an uplink frame structure in LTE. The available resource blocks for the uplink may be partitioned into a data section and a control section. The control section may be formed at the two edges of the system bandwidth and may have a configurable size. The resource blocks in the control section may be assigned to UEs for transmission of control information. The data section may include all resource blocks not included in the control section. The uplink frame structure results in the data section including contiguous subcarriers, which may allow a single UE to be assigned all of the contiguous subcarriers in the data section.

A UE may be assigned resource blocks410a,410bin the control section to transmit control information to an eNodeB. The UE may also be assigned resource blocks420a,420bin the data section to transmit data to the eNodeB. The UE may transmit control information in a physical uplink control channel (PUCCH) on the assigned resource blocks in the control section. The UE may transmit only data or both data and control information in a physical uplink shared channel (PUSCH) on the assigned resource blocks in the data section. An uplink transmission may span both slots of a subframe and may hop across frequency.

FIG. 6is a block diagram of an eNodeB610in communication with a UE650in an access network. In the downlink, upper layer packets from the core network are provided to a controller/processor675. The controller/processor675implements the functionality of the L2 layer. In the downlink, the controller/processor675provides header compression, ciphering, packet segmentation and reordering, multiplexing between logical and transport channels, and radio resource allocations to the UE650based on various priority metrics. The controller/processor675is also responsible for HARQ operations, retransmission of lost packets, and signaling to the UE650.

Provided below are solutions to mitigate device to device interference for asynchronous or synchronous systems, such as a Long Term Evolution (LTE) system. According to one aspect of the present disclosure, a UE is configured to detect interference with an adjacent network and send an interference message to a serving eNodeB so that the serving eNodeB can mitigate the interference. The UE transmits the interference message when the UE encounters difficulty mitigating the interference. The UE may be a victim UE that experiences interference or may be an aggressor UE that causes interference.

According to another aspect of the present disclosure, an eNodeB, or a UE, determines a time division duplex (TDD) configuration of an adjacent network to detect and/or mitigate the interference. Furthermore, the information of the TDD configuration may be used by the eNodeB to avoid specific subframes that experience interference via scheduling, Hybrid Automatic Repeat Request (HARD) timeline changes, and advertising an adjusted TDD configuration to impacted or legacy UEs.

The TDD configuration of an adjacent network may be determined via various methods. For example, in one configuration, networks may exchange TDD configurations over a backhaul communication channel, such as an X2 interface. The eNodeB may signal the TDD configuration to the UE after the eNodeB received the TDD configuration over the backhaul communication channel.

According to another configuration, to determine the TDD configuration, a UE tunes away from the current network to read a system information block (SIB) message of an adjacent network. After determining the TDD configuration, the UE may then forward the TDD configuration to the serving eNodeB via a signaling mechanism. In yet another configuration, the UE and eNodeB exchange the TDD configuration of an adjacent network via pre-defined signaling.

As discussed above, according to one aspect of the present disclosure, the UE uses the TDD configuration of an adjacent cell to mitigate potential interference. Specifically, the UE may use the TDD configuration of an adjacent cell to perform at least two sets of measurements to assist in detecting the presence of bursty interference. In this configuration, the UE performs a first measurement on downlink subframes that do not experience interference, such as cross-device interference. These downlink subframes may be referred to as clean downlink subframes. Furthermore, the UE may perform a second measurement on downlink subframes that overlap with an uplink transmission timing of a neighboring network. These subframes may experience interference and may be referred to as potentially bad subframes or un-clean subframes. In the present configuration, the UE generates and transmits the interference message to an eNodeB based on the link quality measurements for the two sets of measurements and the frequency of the un-clean subframes.

The eNodeB may use the interference message to avoid scheduling a victim UE on un-clean subframes that overlap with uplink transmissions of an adjacent carrier. According to one aspect of the present disclosure, the eNodeB schedules the UE that generated the interference message on an edge of a channel that is furthest away from the aggressor network. That is, the eNodeB may move the victim UE away from the aggressor channel. Moving the victim UE away from the aggressor channel may impact the throughput of the victim UE. Thus, to reduce the impact on the victim UE's throughput, in one configuration, the eNodeB schedules the UE on the edge of the channel only for downlink subframes that overlap with uplink transmission timing of the adjacent network.

According to another aspect of the present disclosure, the UE or eNodeB are unaware of the TDD configuration of an adjacent carrier. In this configuration, the UE detects the presence of cross device interference by detecting bursty interference on a subset of downlink subframes. That is, in one configuration, a UE compares measurements of clean subframes of a TDD configuration with other subframes that are potentially compromised by cross device interference. The clean subframes may include subframes that are always downlink subframes in an LTE TDD configuration. For example, the clean subframes may include subframes 0 and 5. The clean subframes may also be the subframes that are always special subframes in an LTE TDD configuration. For example, the clean subframes may include subframe 2. Furthermore, the clean subframes may also be subframes that are always a special subframe or a downlink subframe. For example, the clean subframes may include subframe 6. In this configuration, the measurements may include a received signal strength indicator (RSSI), channel quality indicator (CQI), and/or signal to interference plus noise ratio (SINR) measurements.

The UE may transmit an interference message to an eNodeB after the UE detects the cross device interference. The interference message may include information such as a level and duty cycle of the bursty interference, link quality measurements with and without the interference, and a TDD configuration of the adjacent carrier. In one configuration, the interference message used for in-device interference is reused for the cross-device coexistence interference by defining specific bit fields. Furthermore, the interference message may include information to specify the type of interference (e.g., cross device interference) and the source of the interference (e.g., LTE, WiFi, Bluetooth, etc.)

According to one aspect of the present disclosure, the eNodeB mitigates potential interface on a downlink control channel, such as a physical downlink control channel (PDCCH). According to one configuration, the eNodeB schedules a narrow band control channel away from the aggressor channel. That is, the eNodeB may schedule the downlink control channel to be on an edge that is away from the aggressor channel as though a virtual guard band exists between the control channel and the aggressor channel.

The solutions of mitigating interference via an eNodeB may be incorporated on their own and may be combined in whole or in part with the solutions discussed in co-owned U.S. patent application Ser. No. 12/851,334, filed Aug. 5, 2010 in the names of DAYAL, et al., U.S. patent application Ser. No. 12/904,509, filed Oct. 14, 2010 in the names of DAYAL, et al., and U.S. patent application Ser. No. 13/004,006, filed Jan. 10, 2011 in the names of DAYAL, et al. the disclosures of which are hereby incorporated by reference in their entireties.

According to another aspect of the present disclosure, the aggressor network mitigates the potential interference. That is, an aggressor scheduler may limit a size of an uplink bandwidth allocation for uplink subframes that may collide with downlink subframes of the victim. Specifically, the interference from an aggressor network may increase as the size of an uplink bandwidth of the aggressor increases and moves closer to the bandwidth of the victim UE. Thus, the aggressor network may mitigate potential interference by limiting a size of an uplink bandwidth allocation for uplink subframes that may collide with downlink subframes of the victim.

In another configuration, UEs associated with an aggressor network are allocated a high transmit power at the farthest edge of the channel (in a frequency domain) from the victim UE. The present configuration is similar to a waterfilling solution that moves UEs on the aggressor network with a higher transmit power away from the victim channel and moves UEs with a lower transmit power towards to victim channel.

In yet another configuration, a UE determines that it is a potential aggressor by measuring the received signal power from the victim network eNodeB. If the UE is near the victim network eNodeB, the UE may assume that UEs associated with the victim network eNodeB are receiving strong signals from the victim network eNodeB, and therefore, the UE may not be an aggressor. Alternatively, the UE may signal to the serving eNodeB that it is a potential aggressor if the UE is far from the victim network eNodeB. In response, the serving eNodeB may schedule the aggressor UE on the furthest edge of the channel away from the victim network, restrict the size of the aggressor UE's bandwidth assignment, and/or cap the aggressor UE's maximum transmission power. Furthermore, if the aggressor network knows the TDD configuration of the victim network then the aggressor network may perform the above techniques only on uplink subframes that overlap with downlink subframes of the victim network.

FIG. 7illustrates a method700for mitigating interference according to an aspect of the present disclosure. A UE determines a time division duplex (TDD) configuration of a non-serving network, as shown in block702. The UE detects interference from the non-serving network based on the TDD configuration of the non-serving network, as shown in block704. The UE signals a base station of the interference based on the detected interference, as shown in block706.

FIG. 8is a diagram illustrating an example of a hardware implementation for an apparatus800employing a processing system814. The processing system814may be implemented with a bus architecture, represented generally by the bus824. The bus824may include any number of interconnecting buses and bridges depending on the specific application of the processing system814and the overall design constraints. The bus824links together various circuits including one or more processors and/or hardware modules, represented by the processor822the modules802,804, and the computer-readable medium826. The bus824may also link various other circuits such as timing sources, peripherals, voltage regulators, and power management circuits, which are well known in the art, and therefore, will not be described any further.

The apparatus includes a processing system814coupled to a transceiver830. The transceiver830is coupled to one or more antennas820. The transceiver830enables communicating with various other apparatus over a transmission medium. The processing system814includes a processor822coupled to a computer-readable medium826. The processor822is responsible for general processing, including the execution of software stored on the computer-readable medium826. The software, when executed by the processor822, causes the processing system814to perform the various functions described for any particular apparatus. The computer-readable medium826may also be used for storing data that is manipulated by the processor822when executing software.

The processing system814includes a detecting module802for determining a TDD configuration of a non-serving network and for detecting interference from the non-serving network based at least in part on the TDD configuration. The processing system814also includes a signaling module804for signaling a base station of the interference based at least in part on the detecting. The modules may be software modules running in the processor822, resident/stored in the computer-readable medium826, one or more hardware modules coupled to the processor822, or some combination thereof. The processing system814may be a component of the UE650and may include the memory660, and/or the controller/processor659.

In one configuration, the UE650is configured for wireless communication including means for detecting. In one configuration, the detecting means may be the controller/processor659, memory660, receive processor656, modulators654, and/or antenna652configured to perform the functions recited by the detecting means. The UE650is also configured to include a means for signaling. In one configuration, the signaling means may be the controller/processor659, memory660, transmit processor668, modulators654, and/or antenna652configured to perform the functions recited by the signaling means. In another configuration, the aforementioned means may be any module or any apparatus configured to perform the functions recited by the aforementioned means.

FIG. 9illustrates a method900for mitigating interference according to an aspect of the present disclosure. In block902, an eNodeB receives an indication that a UE is causing interference with communications of a non-serving network. The eNodeB adjusts communications of the UE to reduce the interference in block904.

FIG. 10is a diagram illustrating an example of a hardware implementation for an apparatus1000employing a processing system1014. The processing system1014may be implemented with a bus architecture, represented generally by the bus1024. The bus1024may include any number of interconnecting buses and bridges depending on the specific application of the processing system1014and the overall design constraints. The bus1024links together various circuits including one or more processors and/or hardware modules, represented by the processor1022the modules1002,1004, and the computer-readable medium1026. The bus1024may also link various other circuits such as timing sources, peripherals, voltage regulators, and power management circuits, which are well known in the art, and therefore, will not be described any further.

The apparatus includes a processing system1014coupled to a transceiver1030. The transceiver1030is coupled to one or more antennas1020. The transceiver1030enables communicating with various other apparatus over a transmission medium. The processing system1014includes a processor1022coupled to a computer-readable medium1026. The processor1022is responsible for general processing, including the execution of software stored on the computer-readable medium1026. The software, when executed by the processor1022, causes the processing system1014to perform the various functions described for any particular apparatus. The computer-readable medium1026may also be used for storing data that is manipulated by the processor1022when executing software.

The processing system1014includes a receiving module1002for receiving an indication that a UE is causing interference with communications of a non-serving network. The processing system1014also includes a adjusting module1004for adjusting communications of the UE to reduce the interference. The modules may be software modules running in the processor1022, resident/stored in the computer-readable medium1026, one or more hardware modules coupled to the processor1022, or some combination thereof. The processing system1014may be a component of the eNodeB610and may include the memory646, and/or the controller/processor675.

In one configuration, the eNodeB610is configured for wireless communication including means for receiving. In one configuration, the receiving means may be the receive processor670, demodulators618, controller/processor675, memory646and/or antenna620configured to perform the functions recited by the receiving means. The eNodeB610is also configured to include a means for adjusting. In one configuration, the adjusting means may be the controller/processor675, memory646, transmit processor616, modulators618and/or antenna620configured to perform the functions recited by the adjusting means. In another aspect, the aforementioned means may be any module or any apparatus configured to perform the functions recited by the aforementioned means.