WO2017172100A1

WO2017172100A1 - Interference mitigation in cellular networks

Info

Publication number: WO2017172100A1
Application number: PCT/US2017/018262
Authority: WO
Inventors: Markus Dominik MUECK; Biljana Badic; Sabine Roessel; Thomas Haustein; Wirth THOMAS; Bernd HOLFELD
Original assignee: Intel IP Corporation
Priority date: 2016-03-31
Filing date: 2017-02-17
Publication date: 2017-10-05
Also published as: DE102016105873A1

Abstract

A radio access node may include a schedule control circuit configured to identify interference caused by one or more transmitters of one or more lower service tiers to one or more mobile terminals, wherein the one or more mobile terminals relate to one or more other lower service tiers or one or more higher service tiers in a shared spectrum, estimate a first time division duplexing (TDD) schedule of the one or more lower service tiers, select a second TDD schedule with a target amount of coinciding downlink and uplink periods and a target amount of opposing downlink and uplink periods relative to the first TDD schedule based on the identified interference from the one or more transmitters of the one or more lower service tiers, and transmit a resource allocation to the one or more mobile terminals to use available spectrum according to the second TDD schedule.

Description

INTERFERENCE MITIGATION IN CELLULAR NETWORKS

Cross-Reference to Related Applications

[0001] This application claims priority to German Patent Application Serial No. 10 2016 105 873.4, which was filed March 31, 2016, and is incorporated herein by reference in its entirety.

Technical Field

[0002] Various embodiments relate generally to methods and devices for interference mitigation in cellular networks.

Background

[0003] Recent developments in radio frequency licensing such as spectrum sharing have introduced new possibilities for Mobile Network Operators (MNOs). In particular, Licensed Spectrum Access (LSA, proposed mainly for Europe in the 2.3-2.4 GHz bands) and Spectrum Access System (SAS, proposed mainly in the U.S. for the 3.55-3.7 bands) may open up access to previously restricted wireless frequency bands for mobile communications by allowing MNOs to share certain spectrum bands with "incumbent" users.

[0004] The respective spectrum by LSA and SAS are located in bands that are used for Long

Term Evolution (LTE) networks that employ Time Division Duplexing (TDD) schemes to divide uplink and downlink transmissions. Such TDD networks may thus utilize a single frequency band that is assigned for downlink transmissions during certain time periods and uplink transmissions during other time periods, thus allowing for bidirectional

communications on a single frequency band. Given the existing availability of mobile devices and transmitters geared toward TDD application on the targeted spectrum, it is foreseeable that LSA and SAS systems may employ TDD networks on the shared spectrum. Brief Description of the Drawings

[0005] In the drawings, like reference characters generally refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the invention. In the following description, various embodiments of the invention are described with reference to the following drawings, in which:

FIG. 1 shows a network architecture for an LSA spectrum sharing system;

FIG. 2 shows a network architecture for an SAS spectrum sharing system;

FIG. 3 shows timing diagrams illustrating a predefined set of uplink-downlink configurations;

FIG. 4 shows a timing diagram illustrating matching uplink and downlink configuration;

FIG. 5 shows an interference scenario between two separate network operators;

FIG. 6 shows a timing diagram illustrating interference for a matching uplink and downlink configuration;

FIG. 7 shows a timing diagram illustrating matching and inverted uplink and downlink configurations;

FIG. 8 shows an internal configuration for a base station, mobile terminal, and control circuit;

FIG. 9 shows a method for adjusting uplink and downlink configurations based on observed interference;

FIG. 10 shows a timing diagram illustrating offset uplink and downlink

configurations;

FIG. 11 shows a method for reporting interference measurements and receiving resource allocations; FIG. 12 shows a first method of managing interference;

FIG. 13 shows a second method of managing interference

FIG. 14 shows a third method of managing interference; and

FIG. 15 shows a method of managing interference.

Description

[0006] The following detailed description refers to the accompanying drawings that show, by way of illustration, specific details and embodiments in which the invention may be practiced.

[0007] The word "exemplary" is used herein to mean "serving as an example, instance, or illustration". Any embodiment or design described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments or designs.

[0008] The words "plural" and "multiple" in the description and the claims expressly refer to a quantity greater than one. Accordingly, any phrases explicitly invoking the

aforementioned words (e.g. "a plurality of [objects]", "multiple [objects]") referring to a quantity of objects expressly refers more than one of the said objects. The terms "group (of)", "set [of]", "collection (of)", "series (of)", "sequence (of)", "grouping (of)", etc., and the like in the description and in the claims, if any, refer to a quantity equal to or greater than one, i.e. one or more.

[0009] It is appreciated that any vector and/or matrix notation utilized herein is exemplary in nature and is employed solely for purposes of explanation. Accordingly, it is understood that the approaches detailed in this disclosure are not limited to being implemented solely using vectors and/or matrices, and that the associated processes and computations may be equivalently performed with respect to sets, sequences, groups, etc., of data, observations, information, signals, etc. Furthermore, it is appreciated that references to a "vector" may refer to a vector of any size or orientation, e.g. including a lxl vector (e.g. a scalar), a IxM vector (e.g. a row vector), and an Mxl vector (e.g. a column vector). Similarly, it is appreciated that references to a "matrix" may refer to matrix of any size or orientation, e.g. including a lxl matrix (e.g. a scalar), a lxM matrix (e.g. a row vector), and an Mxl matrix (e.g. a column vector).

[0010] A "circuit" as user herein is understood as any kind of logic-implementing entity, which may include special-purpose hardware or a processor executing software. A circuit may thus be an analog circuit, digital circuit, mixed-signal circuit, logic circuit, processor, microprocessor, Central Processing Unit (CPU), Graphics Processing Unit (GPU), Digital Signal Processor (DSP), Field Programmable Gate Array (FPGA), integrated circuit, Application Specific Integrated Circuit (ASIC), etc., or any combination thereof. Any other kind of implementation of the respective functions which will be described below in further detail may also be understood as a "circuit". It is understood that any two (or more) of the circuits detailed herein may be realized as a single circuit with substantially equivalent functionality, and conversely that any single circuit detailed herein may be realized as two (or more) separate circuits with substantially equivalent functionality. Additionally, references to a "circuit" may refer to two or more circuits that collectively form a single circuit.

[0011] As used herein, "memory" may be understood as a non-transitory computer-readable medium in which data or information can be stored for retrieval. References to "memory" included herein may thus be understood as referring to volatile or non-volatile memory, including random access memory (RAM), read-only memory (ROM), flash memory, solid- state storage, magnetic tape, hard disk drive, optical drive, etc., or any combination thereof. Furthermore, it is appreciated that registers, shift registers, processor registers, data buffers, etc., are also embraced herein by the term memory. It is appreciated that a single component referred to as "memory" or "a memory" may be composed of more than one different type of memory, and thus may refer to a collective component comprising one or more types of memory. It is readily understood that any single memory component may be separated into multiple collectively equivalent memory components, and vice versa. Furthermore, while memory may be depicted as separate from one or more other components (such as in the drawings), it is understood that memory may be integrated within another component, such as on a common integrated chip.

[0012] The term "base station" used in reference to an access point of a mobile

communication network may be understood as a macro base station, micro base station, Node B, evolved NodeBs (eNB), Home eNodeB, Remote Radio Head (RRH), relay point, etc. As used herein, a "cell" in the context of telecommunications may be understood as a sector served by a base station. Accordingly, a cell may be a set of geographically co-located antennas that correspond to a particular sectorization of a base station. A base station may thus serve one or more cells (or sectors), where each cell is characterized by a distinct communication channel. Furthermore, the term "cell" may be utilized to refer to any of a macrocell, microcell, femtocell, picocell, etc.

[0013] The following description may detail exemplary scenarios involving mobile device operating according to certain 3GPP (Third Generation Partnership Project) specifications, notably Long Term Evolution (LTE) and Long Term Evolution- Advanced (LTE-A). It is understood that such exemplary scenarios are demonstrative in nature, and accordingly may be similarly applied to other mobile communication technologies and standards, such as any

Cellular Wide Area radio communication technology, which may include e.g. a 5th

Generation (5G) communication systems, a Global System for Mobile Communications

(GSM) radio communication technology, a General Packet Radio Service (GPRS) radio communication technology, an Enhanced Data Rates for GSM Evolution (EDGE) radio communication technology, and/or a Third Generation Partnership Project (3GPP) radio communication technology (e.g. UMTS (Universal Mobile Telecommunications System),

FOMA (Freedom of Multimedia Access), 3 GPP LTE (Long Term Evolution), 3 GPP LTE

Advanced (Long Term Evolution Advanced)), CDMA2000 (Code division multiple access 2000), CDPD (Cellular Digital Packet Data), Mobitex, 3G (Third Generation), CSD (Circuit Switched Data), HSCSD (High-Speed Circuit-Switched Data), UMTS (3G) (Universal Mobile Telecommunications System (Third Generation)), W-CDMA (UMTS) (Wideband Code Division Multiple Access (Universal Mobile Telecommunications System)), HSPA (High Speed Packet Access), HSDPA (High-Speed Downlink Packet Access), HSUPA (High- Speed Uplink Packet Access), HSPA+ (High Speed Packet Access Plus), UMTS-TDD (Universal Mobile Telecommunications System - Time-Division Duplex), TD-CDMA (Time Division - Code Division Multiple Access), TD-CDMA (Time Division - Synchronous Code Division Multiple Access), 3GPP Rel. 8 (Pre-4G) (3rd Generation Partnership Project Release 8 (Pre-4th Generation)), 3 GPP Rel. 9 (3rd Generation Partnership Project Release 9), 3 GPP Rel. 10 (3rd Generation Partnership Project Release 10) , 3 GPP Rel. 11 (3rd Generation Partnership Project Release 11), 3GPP Rel. 12 (3rd Generation Partnership Project Release 12), 3 GPP Rel. 13 (3rd Generation Partnership Project Release 12), 3 GPP Rel. 14 (3rd Generation Partnership Project Release 12), 3GPP LTE Extra, LTE Licensed- Assisted Access (LAA), UTRA (UMTS Terrestrial Radio Access), E-UTRA (Evolved UMTS Terrestrial Radio Access), LTE Advanced (4G) (Long Term Evolution Advanced (4th Generation)), cdmaOne (2G), CDMA2000 (3G) (Code division multiple access 2000 (Third generation)), EV-DO (Evolution-Data Optimized or Evolution-Data Only), AMPS (1G) (Advanced Mobile Phone System (1st Generation)), TACS/ETACS (Total Access Communication

System/Extended Total Access Communication System), D-AMPS (2G) (Digital AMPS (2nd Generation)), PTT (Push-to-talk), MTS (Mobile Telephone System), IMTS (Improved Mobile Telephone System), AMTS (Advanced Mobile Telephone System), OLT (Norwegian for Offentlig Landmobil Telefoni, Public Land Mobile Telephony), MTD (Swedish abbreviation for Mobiltelefonisystem D, or Mobile telephony system D), Autotel/PALM (Public

Automated Land Mobile), ARP (Finnish for Autoradiopuhelin,„car radio phone"), NMT

(Nordic Mobile Telephony), Hicap (High capacity version of NTT (Nippon Telegraph and Telephone)), CDPD (Cellular Digital Packet Data), Mobitex, DataTAC, iDEN (Integrated

Digital Enhanced Network), PDC (Personal Digital Cellular), CSD (Circuit Switched Data),

PHS (Personal Handy-phone System), WiDEN (Wideband Integrated Digital Enhanced

Network), iBurst, Unlicensed Mobile Access (UMA, also referred to as also referred to as

3GPP Generic Access Network, or GAN standard)), Wireless Gigabit Alliance (WiGig) standard, mmWave standards in general (wireless systems operating at 10-90 GHz and above such as WiGig, IEEE 802.1 lad, IEEE 802.1 lay, etc.), etc. The examples provided herein are thus understood as being applicable to various other mobile communication technologies, both existing and not yet formulated, particularly in cases where such mobile communication.

[0014] For purposes of this disclosure, radio communication technologies may be classified as one of a Short Range radio communication technology, Metropolitan Area System radio communication technology, or Cellular Wide Area radio communication technology. Short

Range radio communication technologies include Bluetooth, WLAN (e.g. according to any

IEEE 802.11 standard), and other similar radio communication technologies. Metropolitan

Area System radio communication technologies include Worldwide Interoperability for

Microwave Access (WiMax) (e.g. according to an IEEE 802.16 radio communication standard, e.g. WiMax fixed or WiMax mobile) and other similar radio communication technologies. Cellular Wide Area radio communication technologies include GSM, UMTS,

LTE, LTE-Advanced (LTE-A), CDMA, WCDMA, LTE-A, General Packet Radio Service

(GPRS), Enhanced Data Rates for GSM Evolution (EDGE), High Speed Packet Access

(HSPA), HSPA Plus (HSPA+), and other similar radio communication technologies. Cellular

Wide Area radio communication technologies also include "small cells" of such technologies, such as microcells, femtocells, and picocells. Cellular Wide Area radio communication technologies may be generally referred to herein as "cellular" communication technologies. It is understood that exemplary scenarios detailed herein are demonstrative in nature, and accordingly may be similarly applied to various other mobile communication technologies, both existing and not yet formulated, particularly in cases where such mobile communication technologies share similar features as disclosed regarding the following examples.

[0015] The term "network" as utilized herein, e.g. in reference to a communication network such as a mobile communication network, encompasses both an access section of a network (e.g. a radio access network (RAN) section) and a core section of a network (e.g. a core network section).

[0016] As utilized herein, the term "radio idle mode" or "radio idle state" used in reference to a mobile terminal refers to a radio control state in which the mobile terminal is not allocated at least one dedicated communication channel of a mobile communication network. The term "radio connected mode" or "radio connected state" used in reference to a mobile terminal refers to a radio control state in which the mobile terminal is allocated at least one dedicated uplink communication channel of a mobile communication network.

[0017] Unless explicitly specified, the term "transmit" encompasses both direct and indirect transmission. Similarly, the term "receive" encompasses both direct and indirect reception unless explicitly specified.

[0018] In spectrum sharing schemes such as Licensed Spectrum Access (LSA, proposed mainly for Europe in the 2.3-2.4 GHz bands) and Spectrum Access System (SAS, proposed mainly in the U.S. for the 3.55-3.7 bands), Mobile Network Operators (MNOs) may be granted access to previously restricted radio frequency bands. Accordingly, an SAS or LSA "licensee" may license certain targeted frequency bands from "incumbents", and thus may be able to utilize the shared frequency bands.

[0019] While the targeted frequency bands for LSA and SAS may already be officially licensed and/or owned by the incumbents (mainly related to government use), the targeted frequency bands may be underutilized over time and/or space. For example, the incumbents may utilize the targeted frequency bands relatively rarely, and/or may employ the targeted frequency bands only in certain areas. Accordingly, LSA and SAS propose a system in which the targeted frequency bands may be made available to cellular MNOs in scenarios (both geographically and temporally dependent) where the incumbent is not occupying the band. For example, one or more licensed MNOs may be granted access to the targeted frequency bands in scenarios where the incumbent is not actively occupying the targeted frequency bands, and accordingly may utilize the newly available bandwidth for mobile

communications.

[0020] As indicated above, LSA has identified the 2.3-2.4 GHz frequency band

(corresponding to 3GPP LTE Band 40) as a suitable candidate for spectrum sharing, and has additionally been the focus of proposals to also incorporate the 700 MHz and/or 3.6-3.8 GHz bands. Under the proposed LSA framework, a licensee (e.g. an MNO or any other entity that operates a wireless network) may operate a 3GPP LTE network on licensed shared basis, where an licensee may engage in a multi-year sharing contract with an incumbent (such as e.g. 10 years or more). As incumbents maintain prioritized access of the targeted LSA band over all licensees, any licensee may be required to vacate the targeted LSA band for a given geographic area, given frequency range, and given period of time during which an incumbent is accessing the targeted LSA band.

[0021] FIG. 1 shows block diagram 100 illustrating an LSA network architecture. As shown in FIG. 1, LSA Spectrum Management relies on a centralized LSA Repository. Incumbents may be required to provide a-priori usage information to the database on the availability of LSA spectrum on a time- and geographic-basis. Depending on the indicated usage information, an LSA controller may employ control mechanisms to grant/deny spectrum access to various licensed incumbents and issue commands to vacate concerned bands. In this operation operational approach, sensing mechanisms may not be required to support the system for identification of incumbent operation.

[0022] The LSA repository may be a centralized entity that falls outside of the domain of the

MNOs and may interface with the various incumbent users. In the context of LSA, such incumbent users may include wireless cameras (which are allocated spectrum in the targeted LSA band in Europe). Each LSA controller (where each MNO network may include one or more LSA controllers) may thus interface with the LSA repository in order to access the a- priori information provided by the various incumbent users. As shown in FIG. 1, an LSA controller may interface with the Operations, Administration, and Management (OA&M) framework of the MNO in order to provide information on the availability of the shared spectrum to the relevant MNO network components including base stations and end user terminals.

[0023] Similarly to LSA, proposed SAS arrangements may allow licensees to operate a 3GPP LTE network on the 3.55-3.7 GHz frequency band on a shared basis with an incumbent. However, as opposed to the two-tier system between incumbent and licensee (tier- 2 and tier-2, respectively) in LSA, SAS additionally proposes a third tier (tier-3) composed of General Authorized Access (GAA) users. In this three-tier system, tier-2 users, or "Priority Access License" (PAL) users, may only be allocated a limited portion of the entire SAS band (e.g. the PAL spectrum with to 70 MHz bandwidth) in the absence of an incumbent. The remaining spectrum, in addition to any unused portions of the PAL spectrum, may be allotted to GAA users which may typically employ the available tier-3 spectrum for LTE Licensed Assisted Access (LSA) or WiFi-type systems.

[0024] FIG. 2 shows block diagram 200 illustrating an SAS network architecture. In contrast to LSA, SAS may be designed to ensure coexistence between incumbent users that are not able to provide any a-priori information to a centralized database. As indicated above, SAS may employ a three-tiered system composed of incumbents (tier-1), PAL users (tier-2), and

GAA users (tier-3). SAS incumbent users may thus be the highest tier and may generally be protected from interference from the lower-tier PAL and GAA users. Such SAS incumbent users may conventionally be federal or military related, such as Department of Defense (DoD) radars, and may also include other wireless systems such as Fixed Satellite Service (FSS) stations and certain grandfathered terrestrial wireless systems. PAL users (which may include MNOs) may license 10 MHz bands in certain geographic areas (census tracts) and may receive interference protection from GAA users while accepting certain levels of interference from incumbent users. As incumbents are protected from interference from all lower-tier users, PAL users may be required to vacate the licensed band in certain scenarios where incumbent users wish to utilize the licensed band (where the specifics and frequency of such scenarios may depend on the particulars of each license). As the lowest-tier (tier-3), GAA users may not receive any interference protection (thus accepting interference from both PAL and incumbent users) and may similarly face vacation scenarios in order to protect incumbent users.

[0025] As shown in FIG. 2, SAS systems may additionally include an Environmental Sensing Capability (ESC) entity, which may be employed in order to protect incumbent users from interference from PAL and GAA users. Such ESC entities may be composed of a sensor network to detect radio activity by incumbent users, such as e.g. detecting radio activity by military radar, which may allow an SAS entity to instruct PAL and GAA users to cease transmissions on the shared spectrum and/or re-allocate transmission to a different portion of the shared spectrum in order to protect active incumbents.

[0026] Accordingly, SAS networks may include one or more SAS entities (e.g. SAS1 and

SAS2 as shown in FIG. 2) which may interact with licensee users (GAA and PAL) in order to facilitate spectrum sharing while guaranteeing interference protection to higher-tiered users from lower-tiered users. Each SAS entity thus interact with the network architectures of the licensee users. As shown in FIG. 2, a SAS entity may interact with a single licensee transmitter (e.g. CBSD4) or with a network of licensee transmitters (e.g. CBSD1-CBSD3) via a proxy/network manager entity, which may act as an interface between a SAS entity and the various network components of a given MNO's network. Each network transmitter, e.g. a base station or small cell which are referred to as Citizens Broadband Radio Service Devices (CBSD) in the context of SAS, may thus be able to transmit wireless signals to end users (shown in FIG. 2) according to the shared spectrum access permitted by the corresponding SAS entity. SAS entities may aim to ensure that both the CBSDs (such as e.g. base stations and small cells) and end users (e.g. mobile terminals) do not cause excessive interference to incumbent users, which the SAS framework may enforce by specifying certain maximum permitted transmit power levels for CBSDs and end user terminals.

[0027] Both LSA and SAS may additionally provide Quality of Service (QOS) guarantees to licensees, where a licensee that is granted access to a particular frequency band may be guaranteed a certain QOS level. LSA and SAS also resolve congestion problems through central coordination, such as preventing over-utilization of the targeted frequency bands by incumbents and/or other MNOs at a given time at a central control entity. As previously detailed regarding FIGs. 1 and 2, LSA and SAS systems may employ an LSA controller and SAS entity, respectively, to coordinate access between incumbents and secondary users (e.g. registered licensees). Accordingly, these central control entities may grant secondary users access to LSA and SAS spectrum, which may be on an exclusive basis. Secondary users may therefore enjoy dedicated access to the additional spectrum available through LSA and SAS for a given period of time and in a given geographic area.

[0028] As access to LSA and SAS spectrum may be situation-dependent (i.e. time and geographic dependent), shared spectrum may be appropriate for use in a "supplemental" role.

For example, given the variable availability of shared spectrum, it may be impractical (albeit possible) in many scenarios to realize a comprehensive wireless network entirely on shared spectrum. However, licensee MNOs may be able to utilize dedicated licensed spectrum (i.e. exclusively licensed by a licensee) in a primary role while allocating shared spectrum for supplemental uplink and/or downlink. Licensee MNOs may thus be able to rely on the constant availability of dedicated licensed spectrum while utilizing shared spectrum to increase bandwidth when the shared spectrum is available. [0029] Accordingly, shared spectrum may be useful in carrier aggregation schemes, which may commonly have a "primary" carrier and one or more "secondary" carriers. Accordingly, licensees may use shared spectrum for secondary carriers to complement the primary carriers composed of dedicated licensed spectrum. Licensees may employ shared spectrum in this manner in either a supplemental downlink (SDL) or supplemental uplink (SUL) role, and may even be able to adjust the relative balance of shared spectrum for SDL and SUL, such as by allocating a greater number of either uplink frames or downlink frames in a Time Division Duplexing (TDD) system or by allocating more of the shared spectrum bandwidth to either uplink or downlink in a Frequency Division Duplexing (FDD) system.

[0030] Many of the bands identified by the proposed LSA and SAS systems for European and American systems are employed in other regions as TDD bands for Third Generation Partnership Project (3GPP) networks. Accordingly, many Original Equipment Manufacturers (OEM) may already manufacture handsets configured to utilize the LSA and SAS spectrum for 3GPP TDD networks. Accordingly, it may be relatively straightforward for OEMs to enable manufactured handsets to additionally use the LSA and SAS bands for 3GPP TDD in other regions where the LSA and SAS bands were previously unavailable due to wireless frequency licensing restrictions. Of particular interest may be FDD-TDD Carrier Aggregation (CA) in which a licensee may utilize dedicated licensed spectrum for the FDD carrier and shared licensed spectrum for the TDD carrier. The licensee may thus activate the shared licensed spectrum for the TDD carrier when the licensee is granted access to the shared licensed spectrum in the absence of the incumbent.

[0031] Such TDD systems may employ UL/DL configurations that allocate each

Transmission Time Interval (TTI) to either uplink or downlink usage in accordance with the time duplexing characteristics of TDD networks. For example, in an LTE context as specified by the 3 GPP, each of the 10 total subframes of each 10 ms radio frame may be allocated for uplink or downlink transmissions. FIG. 3 shows Table 4.2-2 as specified in 3GPP Technical Specification (TS) 36.211 "Physical channels and modulation", V12.5.0, ("3GPP TS

36.211"), which details the 7 possible UL/DL configurations for TDD operation (Frame structure Type 2). As shown in FIG. 3, each of the 10 subframes in each radio frame may be allocated for uplink, downlink, or as a special subframe (containing uplink pilots, downlink pilots, and a guard period) according to any one of the UL/DL configurations identified by indices 0-6. Subframes 0 and 5 in all of the UL/DL configurations may be reserved for downlink to facilitate for transmission of downlink synchronization signals while subframe 1 may be uniformly reserved for special subframes.

[0032] TDD cells may thus utilize one of the 7 possible UL/DL configurations to dictate uplink and downlink transmission patterns. The network may need to coordinate the UL/DL configurations between adjacent cells to avoid simultaneous transmission and reception on the same frequency in neighboring areas. Accordingly, a "matching" TDD mode may be applied in such neighboring cell environments where the respective UL and DL subframes of adjacent cells match, i.e. where the transmission direction of the adjacent cells is the same. FIG. 4 shows a simplified example of a matching UL/DL configuration in which the subframes of an arbitrary cell "CI" are synchronized, i.e. aligned in time, and "matching", i.e. the same uplink/downlink allocation, with the UL/DL configuration of another arbitrary cell "C2".

[0033] Coordinating matching UL/DL configurations between adjacent cells may be an important task of a network to minimize inter-cell interference. This coordination may be a relatively straightforward procedure in a "cooperative" case where both cells CI and C2 are part of the same network, i.e. operated by the same MNO, and accordingly may communicate directly to coordinate UL/DL configurations or receive control information from a common network entity that assigns CI and C2 a matching UL/DL configuration. The network may additionally have network-level synchronization architecture designed to allow network cells to remain closely synchronized in time with one another. From an interference perspective, matching UL/DL configurations may be well-suited for such cooperative cases as mobile terminals may be free to switch between cells CI and C2 given the common network.

Accordingly, a mobile terminal may connect to cell CI if proximate to cell CI or connect to cell C2 if proximate to cell C2.

[0034] However, matching UL/DL configurations may be sub-optimal in non-cooperative environments, such as where separate MNOs operate cells CI and C2. FIG. 5 shows an exemplary network scenario in which MNOl and MN02 respectively operate BS1 and BS2 as neighboring cells, i.e. on a common carrier frequency in geographically neighboring areas. While neighboring MNO operation on a shared carrier frequency be relatively uncommon in dedicated license spectrum scenarios, such may arise as a result of changing network architecture dynamics such as spectrum sharing systems. For example, MNOl and MN02 may both be licensees in a spectrum sharing system such as SAS or LSA, and accordingly may each have certain licensing rights on spectrum owned by an incumbent. MNOl may have licensed a first census tract (e.g. a geographic area for which a licensee has operating rights) to establish base station BS1 with a coverage area in first census tract as shown in FIG. 5. MNOl may have licensed a second census tract to establish base station BS2 with a coverage area that neighbors the first census tract as shown in FIG. 5. In an exemplary SAS context, both MNOl and MN02 may be tier-2 PALs that independently license a single 10 MHz PAL slot on the first census tract and second census tract, respectively. Additionally, it may be possible for additional MNOs, e.g. MN03 and MN04, to license the same 10 MHz PAL slot in third and fourth census tracts neighboring the first and second census tracts (not explicitly shown in FIG. 5). Accordingly, MNOl and MN02 may operate BS1 and BS2, respectively, on a common frequency in neighboring census tracts. As opposed to a conventional network scenario where MNOs operate on separate spectrum, MNOl and MN02 may need to address interference from another MNO on a common frequency.

[0035] Matching UL/DL configurations may be sub-optimal in non-cooperative cases such as shown between MNOl and MN02 in FIG. 5. FIG. 6 shows a simplified UL/DL configuration for BSl and BS2 in which BSl and BS2 operate on a matching UL/DL configuration, i.e. UL subframes of BSl overlap with UL subframes of BS2 and likewise for DL subframes. As shown in FIG. 5 for UEl, this matching UL/DL configuration may lead to substantial interference problems for certain UEs. UEl may be located at the cell edge of BSl as depicted in FIG. 5 while BS2 may additionally be located proximate to the first census tract and thus in close geographic proximity to UEl.

[0036] As shown in FIG. 6, UEl may experience considerable downlink interference during the aligned DL subframes due to the close proximity of BS2. As UEl is located at the cell edge of BSl, the DL signal received from BSl may be relatively low, which when combined with the high interference from BS2 may severely hinder downlink signal reception at UEl. In a conventional network architecture where BSl and BS2 are operated by a single MNO, UEl may be able to switch (via handover or reselection) from BSl to BS2 due to the closer proximity of UEl to BS2, which may as a result resolve or alleviate the aforementioned interference issues. However, as BSl and BS2 are operated by different MNOs, UEl may not be able to switch from BSl to BS2 in a straightforward manner (e.g. may require roaming), thus preventing a simple resolution of the interference problem. Although not shown in FIG. 5, additional UEs served by BSl and/or BS2 may experience analogous interference problems as a result of the matching UL/DL configuration.

[0037] Accordingly, BSl may adjust its UL/DL configuration in order to resolve such interference issues, i.e. may deviate from the matching UL/DL configuration to obtain a different UL/DL configuration. For example, as opposed to matching each UL and DL subframe of BS2, BSl may instead select "inverted" UL and/or DL subframes, i.e. allocating

UL subframes that overlap with DL subframes of BS2 (i.e. where the transmission directions are different) and vice versa. FIG. 7 shows a simplified example in which BSl utilizes some inverted subframes and some matching subframes. As illustrated in FIG. 7, BSl may select inverted subframes for subframes 3, 4, 7, and 8 with respect to BS2; in other words, BSl may assign subframes 3 and 7 as downlink subframes to "invert" or "reverse" uplink subframes 3 and 7 of BS2 while assigning subframes 4 and 8 as uplink subframes to invert downlink subframes 4 and 8 of BS2. BSl may maintain matching subframes for subframes 1, 2, 5, and 6. Stated another way, BSl may operate in "matched mode" for subframes 1, 2, 5, and 6 relative to BS2 and in "inverted mode" for subframes 3, 4, 7, and 8 relative to BS2. BSl may thus select a UL/DL configuration that provides the desired (or close to the desired) matched/inverted mode schedule relative to BS2. Numerous alternative matched and inverted subframe allocations are possible for BSl and are similarly within the scope of the present disclosure.

[0038] BSl may thus utilize an alternating sequence of matched mode and inverted mode in order to either duplicate or counter the subframes of BS2. BSl may additionally make use of flexible UE scheduling in order to allocate radio resources to certain UEs during matched mode or inverted mode depending on individual UE environments. For example, as detailed regarding FIG. 5 UEl may be poorly suited for matched mode operation, i.e. may suffer from poor downlink reception performance if allocated a downlink subframe that matches with a downlink subframe of BS2. Accordingly, BSl may allocate radio resources to UEl exclusively or primarily during inverted mode (as shown in FIG. 5), i.e. during subframes or individual Resource Elements (REs) that fall within matched mode operation, thus allowing UEl to receive downlink signals from BSl with reduced or negligible interference from BS2. BSl may similarly evaluate the environment of each UE served by BSl and similarly allocate radio resources to each UE dependent on whether UE conditions are better suited for matched or inverted mode relative to BS2. BSl may additionally render a determination as to the amount of time that should be allocated for matched mode relative to inverted mode, i.e. a matched to inverted mode ratio. For example, BSl may assign more subframes as inverted subframes relative to BS2 if a majority of UEs served by BSl are better suited for inverted mode, and vice versa for matched mode if a majority of UEs served by BSl are better suited for matched mode.

[0039] In a cooperative case, i.e. where BSl and BS2 are operated by a single MNO, it may be straightforward for BSl to select a UL/DL configuration that provides a desirable matched/inverted mode schedule relative to BS2. For example, certain TDD networks may have network-level synchronization, and accordingly may assign a uniform UL/DL configuration to all of or large groups of network cells that is synchronized in time.

Accordingly, BSl and BS2 may be assigned the same UL/DL configuration, thus allowing BSl to easily select a different UL/DL configuration that provides a desired matched/inverted mode schedule relative to BS2. Alternatively, BSl and BS2 may be configured to exchange information, either directly or indirectly via the common network architecture, and accordingly may be able to unilaterally or bilaterally provide one another with UL/DL configuration information. BSl may thus be able to determine the UL/DL configuration of BS2 and subsequently select a matched/inverted mode schedule relative to BS2 as exemplified in FIG. 7.

[0040] In LTE-TDD networks, and potentially in future TDD-based communication standards including 5G, BSl may be constrained by an available set of UL/DL configurations such as detailed regarding FIG. 3. BSl may need to select from such an available set of

UL/DL configurations, and accordingly may not be able to independently allocate each subframe for matched or inverted mode. As shown in FIG. 3, some subframes may be uniformly allocated for uplink or downlink across all of the available UL/DL configurations, such as e.g. subframes 0 (DL), 1 (special), 2 (UL), and 5 (DL). BSl may nevertheless have considerable flexibility in selecting a matched/inverted mode schedule with the available

UL/DL configurations in order to obtain an acceptable ratio of matched to inverted subframes with BS2. For example, BSl may select UL/DL configuration 5 if BS2 is utilizing UL/DL configuration 6, thus leading to a relatively high ratio of inverted to matched subframes with BS2 considering the available options for UL/DL configurations. For such overlapping subframes that are locked, BSl may be able to perform further optimization by varying the special subframe length (OFDM symbol length). Depending on the applicable network standards, BSl may not be strictly bound to a predefined set of available UL/DL

configurations and may be able to freely allocate subframes as uplink or downlink subframes. In such contexts, BSl may thus be able to freely select a specific UL/DL configuration that provides any desired matched/inverted mode schedule relative to BS2.

[0041] In the non-cooperative case as introduced above in FIG. 5, BSl may not be able to obtain UL/DL configuration information for BS2 via established channels as BSl and BS2 are located in separate networks. Furthermore, the radio frame schedule of BSl will

probabilistically not be aligned in time with the radio frame schedule of BS2, i.e. the frame boundaries (and accordingly subframe and symbol boundaries) will not be synchronized in time and will be offset by some timing offset. In order to effectively implement a

matched/inverted mode schedule with respect to BS2, BSl may need to determine the timing characteristics of BS2 and determine the UL/DL configuration of BS2 before deciding on an appropriate matched/inverted mode schedule and assigning a resource allocation to the served UEs.

[0042] Accordingly, BSl may include a scheduling control system configured to handle such functionality in order to mitigate interference caused by BS2. FIG. 8 shows a block diagram illustrating the internal configurations of base station 800 (corresponding to BSl) and mobile terminal 810 (corresponding to UE1). Base station 800 may include schedule control circuit 808, which may be configured to perform the matched/inverted mode scheduling operations for interference mitigation (as further detailed below).

[0043] As shown in FIG. 8, mobile terminal 810 may include antenna system 812, RF transceiver 814, and baseband modem 816, which mobile terminal 810 may rely on for mobile communications. Although not explicitly depicted in FIG. 8, mobile terminal 810 may include one or more additional components such as additional hardware, software, or firmware elements including processors/microprocessors, controllers/microcontrollers, memory, other specialty or generic hardware/processors/circuits, etc., in order to support a variety of additional operations. Mobile terminal 810 may also include a variety of user input/output devices (display(s), keypad(s), touchscreen(s), speaker(s), external button(s), camera(s), microphone(s), etc.), peripheral device(s), memory, power supply, extemal device interface(s), subscriber identify module(s) (SIM) etc.

[0044] In an aspect of the disclosure, mobile terminal 810 may be a mobile terminal device having a radio processing circuit (RF transceiver 814) and a baseband processing circuit (baseband modem 816) adapted to interact with the radio processing circuit. Mobile terminal 810 may be configured to communicate with a serving base station according to a first TDD schedule, transmit radio measurements to the serving base station, wherein the radio measurements indicate whether the mobile terminal is better suited for coinciding downlink and uplink periods or opposing downlink and uplink periods relative to an interfering base station, and, if the radio measurements indicate that the mobile terminal is better suited for coinciding downlink and uplink periods relative to the interfering base station, receive a resource allocation for a second TDD schedule that assigns the mobile terminal radio resources that occur during coinciding downlink and uplink periods relative to the interfering base station.

[0045] In an abridged overview of the operation of mobile terminal 810, RF transceiver 814 may receive radio frequency wireless signals via antenna system 812, which may be implemented as e.g. a single antenna or an antenna array composed of multiple antennas. RF transceiver 814 may include various reception circuitry components, which may include analog circuitry configured to process externally received signals such as e.g. mixing circuity to convert externally received RF signals to baseband and/or intermediate frequencies. RF transceiver 814 may also include amplification circuitry to amplify externally received signals, such as power amplifiers (PAs) and/or Low Noise Amplifiers (LNAs), although it is appreciated that such components may also be implemented separately. RF transceiver 814 may additionally include various transmission circuitry components configured to transmit internally received signals, such as e.g. baseband and/or intermediate frequency signals provided by baseband modem 816, which may include mixing circuitry to modulate internally received signals onto one or more radio frequency carrier waves and/or amplification circuitry to amplify internally received signals before transmission. RF transceiver 814 may provide such signals to antenna system 812 for wireless transmission. Further references herein to reception and/or transmission of wireless signals by mobile terminal 102 may thus be understood as an interaction between antenna system 812, RF transceiver 814, and baseband modem 816 as detailed above.

[0046] Baseband modem 816 may be responsible for managing mobile communication functions of mobile terminal 810 and may accordingly be configured to operate in conjunction with RF transceiver 812 and antenna system 812 to transmit and receive mobile

communication signals in accordance with one or more mobile communication protocols. Baseband modem 816 may be responsible for various baseband signal processing operations for both uplink and downlink signal data. Accordingly, baseband modem 816 may obtain and buffer baseband downlink and uplink signals and subsequently provide the buffered downlink signals to various internal components of baseband modem 816 for respective processing operations.

[0047] Baseband modem 816 may be composed of a physical layer (PHY, Layer 1) subsystem and protocol stack (Layer 2 and 3) subsystem. The PHY subsystem may be configured to perform control and processing of physical layer mobile communication functions, including error detection, forward error correction encoding/decoding, channel coding and interleaving, physical channel modulation/demodulation, physical channel mapping, radio measurement and search, frequency and time synchronization, antenna diversity processing, power control and weighting, rate matching, retransmission processing, etc. The PHY subsystem may be controlled by a PHY controller, which may be structurally realized as a processor configured to execute physical layer control software and subsequently control various hardware and software processing elements of the PHY subsystem under the direction of control logic provided therein.

[0048] The protocol stack subsystem may be responsible for the Layer 2 and Layer 3 functionality of the protocol stack. In an LTE context, the protocol stack subsystem may be responsible for Medium Access Control (MAC), Radio Link Control (RLC), Packet Data Convergence Protocol (PDCP), Radio Resource Control (RRC), Non-Access Stratum (NAS), and Internet Protocol (IP) entity processes. The protocol stack subsystem may be realized as a processor configured to execute protocol stack software and control mobile communication operations of mobile terminal under the direction of control logic defined therein. The protocol stack subsystem may interact with the PHY subsystem, such as via an interface with the PHY controller, to request physical layer services as specified by the protocol stack control logic including physical layer configuration and radio measurement. The protocol stack subsystem may supply the PHY subsystem with downlink transport channel data (MAC data) scheduled for subsequent physical layer processing and transmission by the PHY subsystem (via RF transceiver 814 and antenna system 812). The PHY subsystem may conversely receive uplink physical channel data via (via RF transceiver 814 and antenna system 812 ) and perform subsequent physical layer processing on the received uplink physical channel data before providing the uplink physical channel data to protocol stack subsystem 300 as uplink transport channel data (MAC data). Subsequent reference to transmission and reception of signals by mobile terminal 810 may thus be understood as an interaction between antenna system 812, RF transceiver 814, and baseband modem 816 as thus detailed. [0049] Baseband modem 816 may be a multimode modem and may thus be configured to manage mobile communications according to more than one radio access technology.

Baseband modem 816 may thus include multiple physical layer and protocol stack subsystems respectively dedicated to a specific radio access technology. Baseband modem 816 may additionally interface with an application processor of mobile terminal 810 (not explicitly shown in FIG. 8), which may be implemented as a Central Processing Unit (CPU) and configured to execute various applications and/or programs of mobile terminal 812, such as e.g. applications corresponding to program code stored in a memory component of mobile terminal 812 (not explicitly shown in FIG. 2). The application processor may be configured to run an operating system (OS) of mobile terminal 812, and may utilize the interface with baseband modem 816 in order to transmit and receive user data such as voice, video, application data, basic Internet web access data, etc. The application processor may also be configured to control one or more further components of mobile terminal 812, such as user input/output devices (display(s), keypad(s), touchscreen(s), speaker(s), external button(s), camera(s), microphone(s), etc.), peripheral devices, memory, power supply, external device interfaces, etc.

[0050] Baseband modem 816 may thus control communication of mobile terminal 810 with base station 800 over wireless channel 820. As shown in FIG. 8, base station 800 may include antenna system 802, radio subsystem 804, and baseband subsystem 806. Base station 800 may be connected with a core network, and accordingly may act as an interface between the radio access network portion and the core network portion of the licensee communication network. Base station 800 may additionally be connected with schedule control circuit 808, which may either be an integral component of base station 800 or a core network component located within the core network section of the associated network architecture. Both implementations are considered to provide relatively equivalent functionality and are within the scope of the present disclosure. [0051] Radio subsystem 804 may be configured as a Remote Radio Unit (RRU) in a base station context, and thus may be configured to transmit and receive wireless signals. Radio subsystem 804 may include various reception circuitry components, which may include analog circuitry configured to process electrical radio frequency signals such as e.g. mixing circuity to convert received electrical radio frequency signals to baseband and/or intermediate frequencies. Radio subsystem 804 may also include amplification circuitry to amplify received electrical radio frequency signals, such as power amplifiers (PAs) and/or Low Noise Amplifiers (LNAs). Radio subsystem 804 may additionally include various transmission circuitry components configured to transmit internally received signals, such as e.g. baseband and/or intermediate frequency signals provided by baseband subsystem 806, which may include mixing circuitry to modulate internally received signals onto one or more radio frequency carrier waves and/or amplification circuitry to amplify internally received signals before transmission. Radio subsystem 804 may provide such signals to antenna system 802 for wireless transmission.

[0052] Baseband subsystem 806 may be configured as a Baseband Unit (BBU) in a base station context, and may be responsible for controlling radio communications according to a wireless communication protocol, e.g. LTE, UMTS, LTE, CDMA, etc. Baseband subsystem

806 may be structurally embodied as a processor configured to execute program code that defines arithmetic, logical, control and input/output (I/O) processor operations. Baseband subsystem 806 may be configured to control operation of radio subsystem 804 and antenna system 802 in accordance with a wireless communication protocol stack by executing program code of software and/or firmware modules of a wireless communication protocol stack. Although not explicitly depicted in FIG. 8, baseband subsystem 806 may include one or more memory components. Baseband subsystem 806 may retrieve the corresponding program code from the one or more provided memory components and execute the program code of the software and/or firmware modules to control radio subsystem 804 in accordance with control logic provided by various layers of the wireless communication protocol stack, which may include controlling physical (PHY) layer circuitry included as part of baseband subsystem 806 in order to transmit and receive wireless communication signals with radio subsystem 804 and antenna system 812. Further references herein to reception and/or transmission of wireless signals and other processing operations by base station 800 may thus be understood as an interaction between antenna system 802, radio subsystem 804, and baseband subsystem 806 as detailed above.

[0053] Schedule control circuit 808 may be configured to manage uplink and downlink scheduling for base station 800, and accordingly may be configured to interact with baseband subsystem 806 in order to communicate with mobile terminals such as mobile terminal 810 via control signaling in order to allocate uplink and downlink resources in addition to requesting reporting. Schedule control circuit 808 maybe structurally embodied as a processor configured to execute program code that defines arithmetic, logical, control and input/output (I/O) processor operations in accordance with the functionality detailed herein regarding schedule control circuit 808. Accordingly, the functionality of schedule control circuit 808 detailed herein may be embodied as computer-readable instructions or code and stored in a non-transitory computer-readable storage medium for execution by schedule control circuit 808. Schedule control circuit 808 may be included as a component of baseband subsystem 806 (e.g. in a BBU), as a component of radio subsystem 804 (e.g. in an RRU), as a separate internal component of base station 800, as part of the core network connected to base station 800, or as a radio access network entity connected to multiple base stations including base station 800. Regardless of physical location, schedule control circuit 808 may be able to communicate with mobile terminals served by base station 800 via baseband subsystem 806, radio subsystem 804, and antenna system 802 of base station 800.

[0054] As will be further detailed, in an aspect of the disclosure schedule control circuit 808 may be a schedule control circuit configured to estimate a first TDD schedule of an interfering base station, evaluate interference measurements provided by a plurality of mobile terminals to identify one or more interfered mobile terminals, select a second TDD schedule with a target amount of coinciding downlink and uplink periods and a target amount of opposing downlink and uplink periods relative to the first TDD schedule based on the one or more interfered mobile terminals, and transmit a resource allocation to the plurality of mobile terminals according to the second TDD schedule. In another aspect of the disclosure, schedule control circuit 808 may be a schedule control circuit configured to estimate a first time division duplexing (TDD) schedule of an interfering base station, based on radio conditions of one or more mobile terminals, select a second TDD schedule with a target amount of coinciding downlink and uplink periods and a target amount of opposing downlink and uplink periods relative to the first TDD schedule, and transmit a resource allocation to the one or more mobile terminals according to the second TDD schedule.

[0055] As previously indicated, schedule control circuit 808 may be configured to determine the timing characteristics of a nearby interfering base station (such as e.g. BS2) and determine the UL/DL configuration of BS2 in order to decide on an appropriate UL/DL configuration that provides a desired matched/inverted mode schedule and assign a resource allocation to the served UEs. FIG. 9 shows method 900 for managing inter-cell interference, which schedule control circuit 808 may implement to mitigate interference caused by a nearby interfering base station.

[0056] As shown in FIG. 9, schedule control circuit 808 may first need to detect the UL/DL configuration of the interfering base station that is suspected of causing interference on mobile terminals served by base station 800. The interfering base station may be operated by a different MNO than base station 800, and accordingly base station 800 may not be able to directly obtain information of the UL/DL configuration from the interfering base station.

Alternatively, schedule control circuit 808 may employ method 900 to obtain UL/DL configuration from a target BS that is operated by the same MNO without needing to directly exchange information from the interfering base station. Accordingly, while method 900 may be well-suited for separate MNO scenarios, schedule control circuit 808 may alternatively utilize method 900 for common MNO scenarios.

[0057] Schedule control circuit 808 may employ sensing or detection mechanisms to detect the UL/DL configuration of the interfering base station in 910, and thus may detect the

UL/DL configuration of the interfering base station without directly exchanging information with the interfering base station. For example, schedule control circuit 808 may utilize one or more of sensing mobile terminals, dedicated sensing nodes, or other network sensing nodes to provide radio measurements of the interfering base station which schedule control circuit 808 may subsequently utilize to determine the UL/DL configuration of the interfering base station.

[0058] For example, schedule control circuit 808 may assign one or more mobile terminals connected to base station 800 as sensing terminals. Schedule control circuit 808 may request radio measurements from the sensing terminals via control signaling and utilize the radio measurements reported by the sensing mobile terminals to determine the UL/DL

configuration of the interfering base station. For example, schedule control circuit 808 may assign mobile terminal 810 as a sensing terminal via control signaling and request radio measurements from mobile terminal 810. Mobile terminal 810 may then perform the radio measurements (e.g. via the PHY subsystem) and provide the radio measurements to schedule control circuit 808. Schedule control circuit 808 may similarly receive radio measurements from one or more additional mobile terminals assigned as sensing mobile terminals.

[0059] Schedule control circuit 808 may then evaluate the reported radio measurements to determine the UL/DL configuration of the interfering base station. Schedule control circuit

808 may evaluate the changes in radiated power by the interfering base station in order to differentiate between downlink subframes, uplink subframes, and special subframes (if applicable). As the interfering base station is expected to radiate substantial energy during downlink transmission periods, schedule control circuit 808 may be able to determine which time periods are downlink subframes of the interfering base station by identifying time periods during which the assigned sensing terminals detect strong interference from the interfering base station. As uplink subframes may involve only low-power transmissions by served mobile terminals to the interfering base station, schedule control circuit 808 may also able to determine which time periods are uplink subframes of the interfering base station as time periods during which the assigned sensing terminals detect little or no interference from the interfering base station. Schedule control circuit 808 may employ wideband signal power measurements such as Received Signal Strength Indicator (RSSI) measurements (performed at and reported by the assigned sensing mobile terminals) in order to evaluate the changes in radiated power and subsequently determine the UL/DL configuration.

[0060] Schedule control circuit 808 may additionally or alternatively rely on dedicated sensing nodes and other network sensing nodes to similarly receive and evaluate radio measurements of the interfering base station. For example, schedule control circuit 808 may communicate with sensing nodes provided within the network architecture in order to request and receive radio measurements of the interfering base station. Additionally or alternatively, schedule control circuit 808 may rely on Remote Radio Heads (RRHs) or small cells (e.g. femtocells or picocells) that are capable of reporting radio measurements to schedule control circuit 808. Additionally or alternatively, schedule control circuit 808 may rely on a network sensing component such as an Environmental Sensing Controller (ESC) provided as part of a

SAS system (as in FIG. 2) to report radio measurements of the interfering base station.

[0061] Schedule control circuit 808 may thus determine the UL/DL configuration of the interfering base station via radio measurements in 910. Additionally or alternatively, schedule control circuit 808 may be configured to obtain information of the UL/DL configuration of the interfering base station in 910 via an inter-network component that is part of the network hierarchy of base station 800 and has access to synchronization information of the interfering base station, such as e.g. a SAS or LSA component that is connected to both the network of base station 800 and the interfering base station via the SAS or LSA network architecture (FIGs. 1 and 2) . Although 910 is primarily directed towards unilateral detection of the UL/DL configuration of the interfering base station, schedule control circuit 808 may be able to obtain the UL/DL configuration of the interfering base station via a direct or indirect interface with the interfering base station if such is available, which may be appreciably less complex than detecting the UL/DL configuration of the interfering base station via unilateral sensing and may only require a unidirectional exchange of basic scheduling information (such as e.g. the UL/DL configuration index as specified for LTE). Method 900 is thus applicable to both scenarios.

[0062] Schedule control circuit 808 may then apply the detected UL/DL configuration to adjust the UL/DL configuration of base station 800 in order to mitigate interference to mobile terminals served by base station 800. As previously introduced, schedule control circuit 808 may identify a matched/inverted mode schedule relative to the detected UL/DL configuration of the interfering base station that allow schedule control circuit 808 to effectively allocate uplink and downlink resources to the mobile terminals served by base station 800. For example, schedule control circuit 808 may select a matched/inverted mode schedule that contains many inverted subframes relative to the detected UL/DL configuration of the interfering base station if schedule control circuit 808 determines that many mobile terminals served by base station 800 are suffering from excessive downlink interference from the interfering base station. Alternatively, schedule control circuit 808 may either maintain the current UL/DL configuration of base station 800 as the matched/inverted mode schedule or select a matched/inverted mode schedule with more inverted subframes if schedule control circuit 808 determines that few mobile terminals served by base station 800 are suffering from excessive downlink interference from the interfering base station.

[0063] Schedule control circuit 808 may rely on reports provided from mobile terminals served by base station 800 in order to determine whether the current matched/inverted mode schedule of base station 800 relative to the interfering base station should be changed and, if so, select a new matched/inverted mode schedule to alleviate downlink interference to the mobile terminals served by base station 800 caused by the interfering base station.

[0064] Accordingly, schedule control circuit 808 may receive reports from the served mobile terminals in 920, where the reports indicate downlink interference to the served mobile terminals. Schedule control circuit 808 may explicitly request the reports from the served mobile terminals via control signaling for purposes of method 900 or may receive the reports from the served mobile terminals in an independent context, such as standard measurement reporting procedures for mobile terminals in radio connected states. Regardless, schedule control circuit 808 may receive reports from the served mobile terminals in 920 that indicate downlink interference levels caused by the interfering base station.

[0065] Schedule control circuit 808 may utilize additional reported information from the served mobile terminals received in 920 for further consideration in UL/DL configuration selection and resource allocation in 930-940, such as e.g. location information of served mobile terminals. As detailed regarding FIG. 5, the location of a mobile terminal in relation to both base station 800 and the interfering base station may both factor into the interference conditions experienced by the mobile terminal, such as proximity to base station 800 and proximity to the interfering base station. Accordingly, schedule control circuit 808 may be able to utilize such location information (either in conjunction with or in the absence of interference measurement reports) to assess the interference conditions of a mobile terminal.

[0066] Schedule control circuit 808 may thus be able to assess the downlink interference scenarios of the served mobile terminals related to the interfering base station via information reported by the served mobile terminals. Schedule control circuit 808 may then select an appropriate matched/inverted mode schedule in 930 relative to the detected UL/DL configuration of the interfering base station according to the reports received from the served mobile terminals. Schedule control circuit 808 may additionally consider factors such as the concerned frequency band and the concerned technology in UL/DL configuration selection and resource allocation.

[0067] Schedule control circuit 808 may identify a target matched to inverted ratio in 930 dependent on the interference scenarios reported by the served mobile terminals. For example, schedule control circuit 808 may select a high target matched to inverted radio if the reported interference scenarios indicate that matched mode presents an optimized interference scenario for the served mobile terminals or may select a low target matched to inverted ratio if the reported interference scenarios indicate that inverted mode presents an optimized interference scenario for the served mobile terminals.

[0068] Schedule control circuit 808 may then determine an appropriate UL/DL

configuration based on the target matched to inverted ratio and the detected UL/DL configuration of the target BS. Accordingly, schedule control circuit 808 may evaluate the available UL/DL configurations in order to determine which available UL/DL configuration will produce the closest matched to inverted ratio to the target matched to inverted ratio. The set of available UL/DL configurations may depend on whether base station 800 is able to freely choose a UL/DL configuration or is limited to a predefined set of UL/DL

configurations as detailed regarding FIG. 2.

[0069] In order to evaluate the available UL/DL configurations in 930, scheduling control circuit 808 may compare the available UL/DL configurations to the detected UL/DL configuration in order to determine the amount of time that each available UL/DL

configuration would produce matched mode (overlapping UL-UL or DL-DL) and the amount of time that each available UL/DL configuration would produce inverted mode (UL-DL or

DL-UL). Schedule control circuit 808 may then determine the matched to inverted ratio as the radio of matched mode time to inverted mode time, and subsequently select an available

UL/DL configuration that produces a matched to inverted ratio close to the target matched to inverted ratio as the UL/DL configuration in 930. [0070] If the radio frame schedule of the interfering base station is synchronized with the radio frame schedule of base station 800, i.e. aligned in in time with respect to subframe boundaries, the matched to inverted ratio for each available UL/DL configuration may also be the ratio of matched subframes to inverted subframes.

[0071] However, in particular where base station 800 and the interfering base station are operated by separate MNOs, the radio frame schedule of base station 800 may not be aligned in time with the radio frame schedule of the interfering base station. FIG. 10 shows an example in which the radio frame schedule of the interfering base station is offset from the radio frame schedule of base station 800 by some timing offset. Schedule control circuit 808 may be able to identify such an offset by comparing the detected UL/DL configuration of the interfering base station to the current radio frame schedule of base station 800 in order to determine the timing offset relative to the subframe boundaries of the detected UL/DL configuration.

[0072] Schedule control circuit 808 may either adjust the radio frame schedule of base station 800 in 930 or may proceed with an unaligned, i. e. asynchronous, radio frame schedule relative to the interfering base station. As shown in FIG. 10, an unaligned radio frame schedule may produce matched and inverted mode periods that do not align with subframe boundaries. Accordingly, schedule control circuit 808 may be configured to compare the available UL/DL configurations to the detected UL/DL configuration in order to determine the matched mode time periods and inverted mode time periods that the available UL/DL configurations would produce if selected as the UL/DL configuration of base station 800. Such matched and inverted mode periods are respectively identified with "M" and "I" markers in FIG. 10.

[0073] Accordingly, schedule control circuit 808 may be configured to determine the matched to inverted ratio for unaligned radio frame schedules and subsequently select a

UL/DL configuration that produces a matched to inverted ratio is close to the target matched to inverted ratio. It may thus be possible for schedule control circuit 808 to align the radio frame schedule of base station 800 to the interfering base station or proceed with unaligned radio frame schedules in 930. In certain scenarios, it may be exceedingly or preclusively complex for base station 800 to adjust its radio frame schedule, which may include resetting the radio frame schedule via control signaling with the served mobile terminals and the core network. Accordingly, schedule control circuit 808 may proceed with unaligned radio frame schedules in such a scenario. In other scenarios, base station 800 may be capable of dynamically adjusting its radio frame schedule, which may be e.g. provided in TDD networks to allow for base stations and other network components to render scheduling adjustments to maintain synchronization with other network components. Scheduling control circuit 808 may thus adjust the radio frame schedule of base station 800 to align the radio frame schedule with the interfering base station in such scenarios.

[0074] Accordingly, schedule control circuit 808 may determine an appropriate UL/DL configuration in 930 in addition to optionally re-aligning the radio frame schedule of base station 800 to synchronize base station 800 with the interfering base station. Upon selecting the UL/DL configuration in 930, schedule control circuit 808 may proceed to assign uplink and downlink resources to the mobile terminals served by base station 800.

[0075] As previously detailed, schedule control circuit 808 may determine a target matched to inverted ratio based on the interference scenarios reported by the served mobile terminals, where the interference scenarios may indicate that a mobile terminal is better suited for a matched allocation relative to the interfering base station or better suited to an inverted allocation relative to the interfering base station. Accordingly, schedule control circuit 808 may additionally utilize the reported interference scenarios (indicated by reported radio measurements from the served mobile terminals) in order to allocate uplink and downlink resources to the served mobile terminals. [0076] For example, schedule control circuit 808 may identify each served mobile terminal that is identified as being better suited towards matched mode relative to the interfering base station and subsequently allocate uplink and downlink resources to such mobile terminals during the matched time periods of the selected UL/DL configuration. In an aligned case, schedule control circuit 808 may allocate uplink and downlink resources to such mobile terminals during matched subframes relative to the interfering base station, i.e. Resource Elements (REs) that occur during matched subframes and vice versa for inverted subframes. In an unaligned case, schedule control circuit 808 may allocate uplink and downlink resources to such mobile terminals during subframes that are composed of a large amount of matched mode, such as e.g. subframes 3, 7, and/or 8 in the exemplary case of FIG. 10. Depending on the amount of scheduling flexibly available to schedule control circuit 808 for resource allocation, schedule control circuit 808 may assign served mobile terminals that are better suited to matched mode to specific uplink and downlink REs that fall with matched mode periods. Schedule control circuit 808 may place a greater emphasis on assigning served mobile terminals that are better suited to matched mode to downlink resources that are during matched mode periods in recognition that the interfering base station may mainly be causing downlink interference.

[0077] Conversely, schedule control circuit 808 may be configured to allocate uplink and downlink resources to served mobile terminals that are better suited to inverted mode that occur during inverted mode periods relative to the interfering base station in an analogous manner.

[0078] Accordingly, in 940 schedule control circuit 808 allocate the uplink and downlink resources available from the UL/DL configuration that was selected in 930. Schedule control circuit 808 may also transmit control signaling to each served mobile terminal to assign each served mobile terminal with the respective resource allocation. It is noted that the UL/DL configuration and accompanying resource allocations may be specific to the concerned frequency band, and that base station 800 may communicate with the served mobile terminals on one or more additional frequency bands, such as in the case of FDD-TDD carrier aggregation or other uses of the concerned frequency band for SDL and/or SUL. Additionally, schedule control circuit 808 may employ mobile terminals operating on different frequency bands as sensing nodes, which may perform interference measurements on the concerned band as inter-frequency measurements relative to a primary carrier on a different band and subsequently report the measurements to control circuit 808.

[0079] Schedule control circuit 808 may then execute uplink and downlink communication according to the selected UL/DL configuration and assigned resource allocations in 950. Accordingly, schedule control circuit 808 may inform baseband subsystem 806 and radio subsystem 804 of the selected UL/DL configuration and assigned resource allocations and direct baseband subsystem 806 and radio subsystem 804 to communicate with the served mobile terminals according to the selected UL/DL configuration and assigned resource allocations.

[0080] Accordingly, schedule control circuit 808 may mitigate interference caused by an interfering base station on one or more mobile terminals served by base station 800 by selecting an appropriate UL/DL configuration and assigning resource allocations to the served mobile terminals based on the interference conditions of the served mobile terminals. As detailed above, schedule control circuit 808 may determine whether the served mobile terminals are better suited to matched mode operation, i.e. uplink and downlink subframes respectively overlapping with uplink and downlink subframes of the interfering base station, or better suited to inverted mode operation, i.e. uplink and downlink subframes respectively overlapping with downlink and uplink subframes of the interfering base station. Schedule control circuit 808 may utilize such matched or inverted suitability determinations in order to select a target matched to inverted mode ratio, select an appropriate UL/DL configuration according to the target matched to inverted mode ratio, and allocate uplink and downlink resources to the served mobile terminals according to the selected UL/DL configuration.

[0081] As schedule control circuit 808 may be able to rely on unilateral sensing to identify the UL/DL configuration of the interfering base station, schedule control circuit 808 may be particularly applicable to interference caused by a separate MNO. Such interference scenarios may be more prevalent in emerging spectral allocation systems such as SAS and LSA, where two or more different MNOs may license a single shared frequency band in neighboring geographical areas and accordingly need to consider interference caused by a neighboring MNO. Such scenarios may be considered non-cooperative, as base stations of each respective MNO may be unable to directly exchange scheduling information and/or cooperatively perform interference mitigation. Accordingly, each MNO may need to unilaterally address interference, i.e. without cooperating with the other MNO.

[0082] Each of the mobile terminals served by base station 800 (either in radio connected or idle state) may perform counterpart functionality to method 900, where the served mobile terminals may be configured similarly as to mobile terminal 810 as shown in FIG. 8. FIG. 11 shows method 1100, which may be considered a counterpart method to method 1100 performed by the served mobile terminals to perform sensing tasks, report interference measurements, and receive and execute assigned resource allocations from schedule control circuit 808. While method 1100 is described below from the perspective of a single mobile terminal, one or more served mobile terminals of base station 800 may similarly execute method 1100. Furthermore, mobile terminal 800 may perform method 1100 under the control of baseband modem 816, which may execute method 1100 as part of a communication protocol.

[0083] As previously indicated, schedule control circuit 808 may rely on served mobile terminals as sensing nodes to detect the UL/DL configuration of the interfering base station.

Accordingly, schedule control circuit 808 may assign mobile terminal 810 to act as a sensing node, which baseband modem 816 may receive as control signaling in 1110. Baseband modem 816 may proceed to perform radio measurements (e.g. by the PHY subsystem) on the interfering base station and report the radio measurements to base station 800. As previously detailed, mobile terminal 810 may perform signal power measurements such as RSSI measurements to characterize the received power from the interfering base station (which may be treated as interference) and report the signal power measurements to schedule control circuit 808. Schedule control circuit 808 may analyze the received radio measurements to determine the UL/DL configuration of the interfering base station as in 910 of method 900. As indicated, the execution of 1110 may be conditional of whether schedule control circuit 808 assigns mobile terminal 810 as a sensing terminal.

[0084] Baseband modem 816 may then perform and report interference measurements to schedule control circuit 808 in 1120. Baseband modem 816 may either trigger measurement reporting in 1120 in response to received control signaling containing an instruction to report interference measurements or autonomously, e.g. according to a periodic timer or another measurement criteria. The interference measurements may be e.g. RSSI or other wideband signal power measurements that indicate an interference level of the interfering base station. Baseband modem 816 may then report the interference measurements to schedule control circuit 808.

[0085] Schedule control circuit 808 may utilize the received interference measurements to select a UL/DL configuration that provides a desired matched/inverted mode schedule, e.g. on the basis of a target matched to inverted mode ratio relative to the interfering base station, and to select a resource allocation for uplink and downlink resources for each served mobile terminal in 930 and 940, respectively. Schedule control circuit 808 may then transmit the assigned resource allocations to each respective served mobile terminal, which baseband modem 816 may receive in 1130 in response to the reported interference measurements. As detailed regarding method 900, schedule control circuit 808 may assign uplink and downlink resources that occur during matched mode to served mobile terminals that are better suited to matched operation relative to the interfering base station, i.e. indicate that interference would be reduced if assigned matched mode resources, and vice versa for inverted mode.

[0086] Baseband modem 816 may thus receive the assigned resource allocation in 1130 and proceed to execute uplink and downlink communications according to the assigned resource allocation in 1140. Accordingly, baseband modem 816 may execute uplink transmission and downlink reception according to the assigned resource allocation in 1140 in order to transmit and receive radio signals with base station 800.

[0087] Schedule control circuit 808 may thus interact with mobile terminal 810 and other served mobile terminals in order to address interference caused by the interfering base station on the mobile terminals. Schedule control circuit 808 and the served mobile terminals may perform methods 900 and 1100 repeatedly in order to address both ineffective resource allocation assignments and time-varying network conditions. As shown in FIG. 9, schedule control circuit 808 may repeat 920-950 by receiving updated reports from the served mobile terminals in 920, selecting an updated UL/DL configuration in 930 (if applicable) based on the updated reports, assigning updated resource allocations to the served mobile terminals in 940 (if applicable) based on the updated reports and updated UL/DL configuration, and executing uplink and downlink communications according to the updated UL/DL configuration and updated resource allocations in 950.

[0088] Similarly, mobile terminal 810 and the additional mobile terminals served by base station 800 may obtain and report updated interference measurements to schedule control circuit 808 in 1120, receive an updated resource allocation from schedule control circuit 808 in response to the reported updated interference measurements (if applicable) in 1130, and execute uplink and downlink communications according to the updated assigned resource allocation (if applicable) in 1140. [0089] By repeating methods 900 and 1100, schedule control circuit 808 and mobile terminal 810 may address ineffective resource allocation assignments and time-varying network conditions. For example, an initial selection of a UL/DL configuration by schedule control circuit 808 in 930 may not be effective, and the served mobile terminals may not see an appreciable reduction in or may even experience an increase in downlink interference caused by the interfering base station. Accordingly, schedule control circuit 808 may receive updated reports from the served mobile terminals in 920 and subsequently select an updated UL/DL configuration that may be more effective in countering the interference. Similarly, schedule control circuit 808 may be able to adjust the individual resource allocations (either with or without selecting an updated UL/DL configuration) for certain served mobile terminals if the served mobile terminals report high interference levels in 920.

[0090] Similarly, it may be important for schedule control circuit 808 and the served mobile terminals to repeat methods 900 and 1100 to address time-varying interference and mobile environment conditions. For example, one or more of the served mobile terminals may be moving (e.g. due to user movement), which may affect the level of interference caused by the interfering base station according to the varying position of the served mobile terminals relative to the interfering base station. Accordingly, schedule control circuit 808 may continue to receive updated reports from the served mobile terminals and subsequently react to the updated reports by adjusting the individual resource allocation for the served mobile terminals and/or updating the selected UL/DL configuration. Schedule control circuit 808 may additionally be configured to utilize predictive mobility operation of the served mobile terminals to preemptively adjust the resource allocation and/or selected UL/DL configuration. For example, schedule control circuit 808 may be able to determine a mobility conditions of the served mobile terminals, such as e.g. static, nomadic, pedestrian, mobile, high-speed, low- speed, etc., which schedule control circuit 808 may determine based on reported location and/or mobility information from the served mobile terminals (e.g. geolocation tags or movement reports) or from derived signal measurements. Schedule control circuit 808 may utilize such to predictively assign resource allocations to individual mobile terminals, such as by using predicted or planned trajectories. For example, schedule control circuit 808 may determine that a mobile terminal is moving on a high-speed vehicle such as a train or car and subsequently predict the movement path of the mobile terminal using a current trajectory. Schedule control circuit 808 may then be able to determine whether the mobile terminal is better suited for matched or inverted mode, such as by determining whether the predicted traj ectory of the mobile terminal will bring the mobile terminal in proximity to the interfering base station as in the exemplary scenario of FIG. 5. Schedule control circuit 808 may then predicatively adjust the resource allocation of the mobile terminal, such as e.g. to favor inverted mode operation, in order to preemptively address future interference conditions of the mobile terminal according to the predicted trajectory.

[0091] Interference levels caused by the interfering base station may vary for other reasons, such as e.g. if incumbent activity in a spectrum sharing context forces the MNO operating the interfering base station to cease radio activity with the interfering base station, thus eliminating interference issues, or vice versa for a previously dormant neighboring MNO to activate an interfering base station. By repeating methods 900 and 1100, schedule control circuit 808 and the served mobile terminals may adapt to time-varying interference conditions in order to effectively dynamically address interference. Although not explicitly depicted in

FIGs. 9 and 11, schedule control circuit 808 and the served mobile terminals may additionally repeat 910 and 1110 in order to detect whether the UL/DL configuration of the interfering base station has changed, such as e.g. due to timing drift or to a dynamic shift in UL/DL configuration triggered by the interfering base station. Schedule control circuit 808 and the served mobile terminals assigned as sensing nodes may thus periodically repeat 910 and 1110 in order to re-detect the UL/DL configuration of the interfering base station and execute 920-

950 and 1120-1140 based on an updated UL/DL configuration of the interfering base station. [0092] Schedule control circuit 808 and the served mobile terminals may thus dynamically adapt the UL/DL configuration and resource allocations over time in response to varying interference conditions, which may include alternating periods of activity and inactivity by a neighboring MNO in spectrum sharing system. For example, in the non-cooperative case

MNOl may operate base station 800 (BS1) in the first census tract while MN02 operates the interfering base station (BS2) in the second census tract as shown in FIG. 5. Incumbent activity may affect the operation of BS1 and BS2 by MNOl and MN02, such as if the incumbent reclaims the shared spectrum in the first and/or second census tracts for incumbent operation and thus forbids MNOl and/or MN02 from operating BS1 and BS2. It may typically be assumed that the allocation of licensee slots (e.g. PAL/GAA access slots) may be relatively long-term, e.g. the incumbent may reclaim shared spectrum relatively infrequently.

However, in particular when considering evolution of shared spectrum technologies, shared spectrum allocation and reclamation by an incumbent may occur more frequently, such as where a shared spectrum system may grant licensees access to shared spectrum for relatively short durations of time when the incumbent is absent (which may not be easily predicted).

Such rapid allocation and reclamation may potentially lead to oscillation effects, where schedule control circuit 808 may rapidly cycle through a given partem of UL/DL

configuration selections in response to frequent allocation and reclamation of the shared spectrum. In order to prevent such oscillation effects, the corresponding shared spectrum controllers (e.g. SAS entities or LSA controllers) may be informed of configuration changes such as UL/DL configuration and PAL/GAA slot allocation changes. The shared spectrum controllers may then observe how the configuration of each system evolves and detects oscillation effects, i.e. cycles through the same circular pattern of configurations, via a simple search for repeating configuration patterns. The shared spectrum controller may then enforce reconfiguration rules to prevent the occurrence of such oscillation effects, such as by enforcing that a configuration must remain static for a predetermined period of time (i.e. forcing schedule control circuit 808 to maintain a selected UL/DL configuration and/or resource allocation for a predetermined period of time before updating), by prohibiting certain reconfiguration sequences (e.g. prohibiting schedule control circuit 808 from cyclically switching between arbitrary UL/DL configurations A- B- C- A- B- C- A... , which may e.g. trigger prevention of UL/DL configuration B), by enforcing that not all systems may change their corresponding configurations simultaneously (such as e.g. by preventing schedule control circuit 808 from reconfiguring the UL/DL configuration at substantially the same time as a counterpart schedule control circuit of BS2, which may be handled by a shared spectrum controller interfaced with both MNOl and MN02), etc.

[0093] The served mobile terminals may additionally consider Device to Device (D2D, also known as Proximity Services (ProSe)) communications in the context of method 1100. For example, one or more mobile terminals may be in an Out of Coverage (OOC) scenario and may even be located in the coverage area of the interfering base station. Accordingly, such mobile terminals may be able to provide high accuracy measurements of the interfering base station due to the potentially close proximity to the interfering base station, which may be particularly useful for detecting the UL/DL configuration of the interfering base station. However, as such mobile terminals are experiencing an OOC scenario, these mobile terminals may not be able to directly provide schedule control circuit 808 with the radio measurements. In such a scenario, these mobile terminals may utilize other in-coverage mobile terminals as D2D relay devices and accordingly provide the radio measurements of the interfering base station to in-coverage mobile terminals, which may subsequently forward the radio measurements to schedule control circuit 808.

[0094] Schedule control circuit 808 may similarly expand the concept of uplink and downlink resource allocation to "transmit and receive resource allocations" in order to include such D2D transmissions. For example, an MNO may employ shared spectrum for D2D communications in addition to conventional uplink and downlink communications, and may thus allow mobile terminals to utilize the shared spectrum to perform D2D communications with other mobile terminals. Accordingly, schedule control circuit 808 may select transmit and receive configurations and allocate transmit and receive resources to the served mobile terminals intended to reduce interference caused by the interfering base station, which the mobile terminals may subsequently utilize to transmit and receive D2D communications with other mobile terminals.

[0095] In conclusion, schedule control circuit 808 may implement method 900 in conjunction with the served mobile terminals of base station 800 to mitigate interference to the served mobile terminals caused by an interfering base station. These same concepts may be analogously applied to multi-interfering base station cases, such as where two or more base stations cause interference to served mobile terminals. Schedule control circuit 808 may employ the interference mitigation techniques detailed herein in either cooperative or non- cooperative cases, which may influence the UL/DL configuration detection of 910.

Accordingly, the interfering base station may either be operated by the same network or a different network than base station 800.

[0096] While the above description may focus on the perspective of base station 800 (i.e. active operations by base station 800 and schedule control circuit 800), the interfering base station may analogously apply method 900 and the related procedures from its own perspective (e.g. at a counterpart schedule control circuit dedicated to the interfering base station), thus providing interference mitigation dedicated to the interfering base station.

[0097] In certain scenarios, the interfering base station may not be capable of dynamically controlling TDD mode allocation. For example, base station 800 may employ 3 GPP LAA

(standalone, such as MuLTEfire) while the interfering base station may utilize WiFi (e.g. may be a WiFi access point) that coexists with base station 800 on the 3.5 GHz GAA band

(although both systems may need to be modified from current definitions to support integration with a SAS entity to perform incumbent protection). In such an exemplary scenario, base station 800 may utilize an LAA definition that allows dynamic adjustment of the TDD mode allocation while the interfering base station may not be permitted to adjust the WiFi allocation. Accordingly, base station 800 may need to take initiative to adapt the TDD mode allocation to reduce and/or avoid interference, as base station 800 may be permitted to do so under the LAA definition while the interfering base station is conversely prohibited.

[0098] Additionally, schedule control circuit 808 may implement method 900 for base station 800 in the event of neighboring radio systems that fully overlap or partially overlap with the signal bandwidth of base station 800. For example, the interfering base station may utilize an identical signal bandwidth as base station 800, i.e. an operating that fully overlaps with the signal bandwidth of base station 800. Alternatively, the interfering base station may use a different signal bandwidth that only partially overlaps with base station 800. For example, the base station 800 may utilize a 20 MHz TDD signal while the interfering base station uses a 10 MHz TDD signal that partially overlaps with the 20 MHz carrier of base station 800, such as e.g. an overlap of any value between 0 and 10 MHz. In such a scenario, schedule control circuit 808 may employ method 900 to the overlapping bandwidth in order to reduce interference thereon, thus providing mutual protection to both systems (where the interfering base station may additionally implement method 900 from its own perspective on the overlapping bandwidth). Similar scenarios with partially overlapping bandwidth may also occur in carrier aggregation contexts, such as where one or both of base station 800 and the interfering base station use contiguous or non-contiguous carrier aggregation. Accordingly, there may be a TDD interference scenario where some TDD carriers overlap and other TDD carriers do not overlap (or all TDD carriers may overlap). Accordingly, schedule control circuit 808 may employ method 900 on the overlapping carriers in order to mitigate interference (e.g. some of the overlapping carriers, only overlapping carriers, or all carriers (although non-overlapping carriers will not have be notably affected)). [0099] Furthermore, schedule control circuit 808 may implement method 900 in the event that the signal bandwidth of base station 800 and the interfering base station do not overlap but fall in neighboring bands. As base station 800 and the interfering base station operate in neighboring bands, one system may interfere with the second system through out-of-band or spurious emissions. In such a case, schedule control circuit 808 may implement method 900 in the same manner as if the respective signal bandwidths overlap (even if the signal bandwidths fall in neighboring bands). Schedule control circuit 808 may additionally apply method 900 if the respective signal bandwidths of base station 800 and the interfering base station are separated by a gap in the frequency domain.

[0100] Furthermore, schedule control circuit 808 may apply method 900 regardless of whether the interfering base station operating a TDD system or an FDD system. While the above disclosure may reference a neighboring TDD system (and associated TDD

uplink/downlink configuration), schedule control circuit 808 may similarly implement method 900 in the event that the interfering base station is operating in FDD, i.e. either with one or both of the UL FDD carrier and DL FDD carrier of the interfering base station overlapping (or neighboring) with the signal bandwidth of base station 800. Accordingly, there may be interference between the TDD carrier of base station 800 with either i) the UL FDD Carrier, ii) the DL FDD Carrier or iii) both. In this case, the interfering base station may not be able to reconfigure the FDD system (although the interfering base station may be able to consider a (dynamic) switching of the UL FDD and UL FDD frequency bands over time such that the overall lowest interference is reached). Accordingly, schedule control circuit 808 may adjust the UL/DL configuration of base station 800 over time such that the interference is minimized. Schedule control circuit 808 may thus observe low load time slots of the interfering FDD carrier(s) (i.e. either UL, DL, or both) and subsequently schedule the TDD transmissions during the low load FDD transmission periods of the interfering base station. Schedule control circuit 808 may thus schedule TDD transmissions independently to address one or both of overlapping FDD UL and FDD DL carriers.

[0101] Certain functionality detailed above may be distributed across multiple devices. For example, as previously detailed base station 800 may utilize sensing mobile terminals, dedicated sensing nodes, or other network sensing nodes to determine the transmission schedule of the interfering base station. Altematively, a third device may be employed to monitor the transmissions of both base station 800 and the interfering base station, and may identify the frequency carriers/bands where collisions (i.e. interference) occurs. Altematively, a multitude of such "third devices" may be employed in order to observe transmissions of base station 800 and the interfering base station, Such "third devices" may supply schedule control circuit 808 (and/or a counterpart schedule control circuit for the interfering base station) with the observed measurements, and may be any one or more of base stations, small cells, access points, mobile terminals, or any other type of user, home, professional, office, governmental, or Public Protection and Disaster Relief (PPDR) equipment on the network and/or terminal side.

[0102] Furthermore, the coordination of adjusting TDD allocations/modes between base station 800 and the interfering base station may be performed by a SAS entity, Proxy /Network

Manager, or any other system entity. In such cases, a first system (either base station 800 or the interfering base station) may send a TDD configuration request to the control entity

(optionally including indications such as intended usage over time and frequency of TDD transmissions/receptions, possible (preferred) TDD mode allocations (which may change over time), geographic location as well as output power levels of the transmitters (or at least infrastructure such as base stations, small cells, access points, etc.) etc.) while the second system (the other of base station 800 and the interfering base station) may send the same information (relating to the second system) to the control entity. The control entity may then identify a preferred allocation of TDD modes over the two (or more) systems (which may change over time) and subsequently may communicate a preferred mode allocation (which may change over time) to all such concerned systems.

[0103] Additionally, while the above description may address interference between two neighboring systems, such concepts are considered demonstrative and may be expanded to more than two systems that are interfering with each other as a given cell (or census tract) may share its frequency allocation with more than one neighbor. In a multi-system

configuration, a TDD mode allocation across all systems may be identified to minimize the overall interference between all of the involved systems, which may be based on a metric such as e.g. signal-to-interference-plus-noise ratio (SINR). For example, such a multi-system configuration may aim to select a TDD mode allocation that maximizes the SINR over all involved systems.

[0104] FIG. 12 shows method 1200 for managing interference. As shown in FIG. 12, method 1200 includes estimating a first time division duplexing (TDD) schedule of an interfering base station (1210), evaluating interference measurements provided by a plurality of mobile terminals to identify one or more interfered mobile terminals (1220), selecting a second TDD schedule with a target amount of coinciding downlink and uplink periods and a target amount of opposing downlink and uplink periods relative to the first TDD schedule based on the one or more interfered mobile terminals (1230), and transmitting a resource allocation to the plurality of mobile terminals according to the second TDD schedule (1240).

[0105] FIG. 13 shows method 1300 of managing interference. As shown in FIG. 13, method 1300 includes estimating a first time division duplexing (TDD) schedule of an interfering base station (1310), based on radio conditions of one or more mobile terminals, selecting a second TDD schedule with a target amount of coinciding downlink and uplink periods and a target amount of opposing downlink and uplink periods relative to the first TDD schedule (1320), and transmitting a resource allocation to the one or more mobile terminals according to the second TDD schedule (1330). [0106] FIG. 14 shows method 1400 for performing radio communications at a mobile terminal. As shown in FIG. 14, method 1400 includes communicating with a serving base station according to a first time division duplexing (TDD) schedule (1410), transmitting radio measurements to the serving base station, wherein the radio measurements indicate whether the mobile terminal is better suited for coinciding downlink and uplink periods or opposing downlink and uplink periods relative to an interfering base station (1420), and if the radio measurements indicate that the mobile terminal is better suited for coinciding downlink and uplink periods relative to the interfering base station, receiving a resource allocation for a second TDD schedule that assigns the mobile terminal radio resources that occur during coinciding downlink and uplink periods relative to the interfering base station (1430).

[0107] FIG. 15 shows method 1500 for managing interference used in mobile

communication. As shown in FIG. 15, method 1500 includes identifying interference caused by one or more transmitters of one or more lower service tiers to one or more mobile terminals, wherein the one or more mobile terminals relate to one or more other lower service tiers or one or more higher service tiers in a shared spectrum (1510), estimating a first time division duplexing (TDD) schedule of the one or more lower service tiers (1520), selecting a second TDD schedule with a target amount of coinciding downlink and uplink periods and a target amount of opposing downlink and uplink periods relative to the first TDD schedule based on the identified interference from the one or more transmitters of the one or more lower service tiers (1530), and transmitting a resource allocation to the one or more mobile terminals to use available spectrum according to the second TDD schedule (1540).

[0108] In one or more further exemplary aspects of the disclosure, one or more of the features described above in reference to FIGS. 1-11 may be further incorporated into methods 1200, 1300, 1400, and/or 1500. In particular, methods 1200, 1300, 1400, and/or 1500 may be configured to perform further and/or alternate processes as detailed regarding schedule control circuit 808 or mobile terminal 810. [0109] The terms "user equipment", "UE", "mobile terminal", "user terminal", etc., may apply to any wireless communication device, including cellular phones, tablets, laptops, personal computers, wearables, multimedia playback devices, consumer/home appliances, vehicles, etc., and any number of additional electronic devices capable of wireless

communications.

[0110] It is appreciated that implementations of methods detailed herein are demonstrative in nature, and are thus understood as capable of being implemented in a corresponding device. Likewise, it is appreciated that implementations of devices detailed herein are understood as capable of being implemented as a corresponding method. It is thus understood that a device corresponding to a method detailed herein may include a one or more components configured to perform each aspect of the related method.

[0111] The following examples pertain to further aspects of the disclosure:

[0112] Example 1 is a method for managing interference used in mobile communication, the method including identifying interference caused by one or more transmitters of one or more lower service tiers to one or more mobile terminals, wherein the one or more mobile terminals relate to one or more other lower service tiers or one or more higher service tiers in a shared spectrum, estimating a first time division duplexing (TDD) schedule of the one or more lower service tiers, selecting a second TDD schedule with a target amount of coinciding downlink and uplink periods and a target amount of opposing downlink and uplink periods relative to the first TDD schedule based on the identified interference from the one or more transmitters of the one or more lower service tiers, and transmitting a resource allocation to the one or more mobile terminals to use available spectrum according to the second TDD schedule.

[0113] In Example 2, the subject matter of Example 1 can optionally include wherein estimating the first TDD schedule of the one or more lower service tiers includes receiving measurement reports from one or more measurement nodes, and estimating the first TDD schedule based on the measurement reports. [0114] In Example 3, the subject matter of Example 2 can optionally include wherein the one or more measurement nodes comprise at least one of the one or more mobile terminals of the one or more other lower service tiers or the one or more higher service tiers in the shared spectrum.

[0115] In Example 4, the subject matter of any one of Examples 1 to 3 can optionally include wherein estimating the first TDD schedule of the one or more lower service tiers includes identifying estimated downlink and uplink periods of the one or more lower service tiers based on measurement reports received from at least one of the one or more mobile terminals, and identifying a TDD schedule from a predefined set of TDD schedules that matches with the estimated downlink and uplink periods as the first TDD schedule.

[0116] In Example 5, the subject matter of any one of Examples 1 to 4 can optionally further include identifying a first set of mobile terminals from the one or more mobile terminals that are assigned radio resources during coinciding downlink and uplink periods relative to the first TDD schedule and identifying a second set of mobile terminals from the one or more mobile terminals that are assigned radio resources during opposing downlink and uplink periods relative to the first TDD schedule, and selecting the target amount of coinciding downlink and uplink periods and the target amount of opposing downlink and uplink periods based on the first set of mobile terminals and the second set of mobile terminals.

[0117] In Example 6, the subject matter of any one of Examples 1 to 4 can optionally further include identifying a first set of mobile terminals from the one or more mobile terminals that are assigned radio resources during coinciding downlink and uplink periods relative to the first TDD schedule and identifying a second set of mobile terminals from the one or more mobile terminals that are assigned radio resources during opposing downlink and uplink periods relative to the first TDD schedule, and determining the resource allocation for the one or more mobile terminals by assigning radio resources to the first set of mobile terminals that occur during opposing downlink and uplink subframes relative to the first TDD schedule and by assigning radio resources to the second set of mobile terminals that occur during coinciding downlink and uplink subframes relative to the first TDD schedule.

[0118] In Example 7, the subject matter of any one of Examples 1 to 6 can optionally further include communicating with the one or more mobile terminals according to a third TDD schedule prior to selecting the second TDD schedule.

[0119] In Example 8, the subject matter of Example 7 can optionally include wherein the interference measurements characterize radio conditions experienced by the one or more of mobile terminals while operating according to the third TDD schedule.

[0120] In Example 9, the subject matter of any one of Examples 1 to 8 can optionally further include communicating with the one or more mobile terminals according to the resource allocation using spectrum licensed with a spectrum sharing system.

[0121] In Example 10, the subject matter of Example 9 can optionally include wherein the spectrum sharing system is a Licensed Shared Access (LSA) or Spectrum Access System (SAS) system.

[0122] Example 11 is a non-transitory computer readable medium storing instructions that when executed by a processor direct the processor to perform the method of any one of Examples 1 to 10.

[0123] Example 12 is a base station configured to perform the method of any one of Examples 1 to 10.

[0124] Example 13 is a radio access node configured to perform the method of any one of Examples 1 to 10.

[0125] Example 14 is a control circuit configured to perform the method of any one of Examples 1 to 10.

[0126] Example 15 is a radio access node including a schedule control circuit configured to identify interference caused by one or more transmitters of one or more lower service tiers to one or more mobile terminals, wherein the one or more mobile terminals relate to one or more other lower service tiers or one or more higher service tiers in a shared spectrum, estimate a first time division duplexing (TDD) schedule of the one or more lower service tiers, select a second TDD schedule with a target amount of coinciding downlink and uplink periods and a target amount of opposing downlink and uplink periods relative to the first TDD schedule based on the identified interference from the one or more transmitters of the one or more lower service tiers, and transmit a resource allocation to the one or more mobile terminals to use available spectrum according to the second TDD schedule.

[0127] In Example 16, the subject matter of Example 15 can optionally further include a baseband processing circuit configured to manage radio communications with the one or more of mobile terminals.

[0128] In Example 17, the subject matter of Example 15 or 16 can optionally include wherein schedule control circuit is embodied as wired hardware circuitry.

[0129] In Example 18, the subject matter of Example 15 or 16 can optionally include wherein the schedule control circuit is embodied as a processor to execute programmable software instructions.

[0130] In Example 19, the subject matter of any one of Examples 15 to 18 can optionally further include a transceiver configured to communicate with the one or more of mobile terminals according to the resource allocation.

[0131] In Example 20, the subject matter of any one of Examples 15 to 18 can optionally further include a transmitter, wherein the schedule control circuit is configured to transmit the resource allocation to the one or more of mobile terminals with the transmitter.

[0132] In Example 21, the subject matter of any one of Examples 15 to 18 can optionally include wherein the schedule control circuit is configured to estimate the first TDD schedule of the one or more lower service tiers by receiving measurement reports from one or more measurement nodes, and estimating the first TDD schedule based on the measurement reports. [0133] In Example 22, the subject matter of Example 21 can optionally include wherein the one or more measurement nodes comprise at least one of the one or more mobile terminals of the one or more other lower service tiers or the one or more higher service tiers in the shared spectrum.

[0134] In Example 23, the subject matter of any one of Examples 15 to 22 can optionally include wherein the schedule control circuit is configured to estimate the first TDD schedule of the one or more lower service tiers by identifying estimated downlink and uplink periods of the one or more lower service tiers based on measurement reports received from at least one of the one or more mobile terminals, and identifying a TDD schedule from a predefined set of TDD schedules that matches with the estimated downlink and uplink periods as the first TDD schedule.

[0135] In Example 24, the subject matter of any one of Examples 15 to 23 can optionally include wherein the schedule control circuit is further configured to identify a first set of mobile terminals from the one or more mobile terminals that are assigned radio resources during coinciding downlink and uplink periods relative to the first TDD schedule and identifying a second set of mobile terminals from the one or more mobile terminals that are assigned radio resources during opposing downlink and uplink periods relative to the first TDD schedule, and selecting the target amount of coinciding downlink and uplink periods and the target amount of opposing downlink and uplink periods based on the first set of mobile terminals and the second set of mobile terminals.

[0136] In Example 25, the subject matter of Example 24 can optionally include wherein the schedule control circuit is configured to select the target amount of coinciding downlink and uplink periods and the target amount of opposing downlink and uplink periods based on the first set of mobile terminals and the second set of mobile terminals by selecting a higher target amount of opposing downlink and uplink periods than the target amount of coinciding downlink and uplink periods if the first set of mobile terminals is larger than the second set of mobile terminals, and selecting a higher target amount of coinciding downlink and uplink periods than the target amount of opposing downlink and uplink periods if the second set of mobile terminals is larger than the first set of mobile terminals.

[0137] In Example 26, the subject matter of any one of Examples 15 to 23 can optionally include wherein the schedule control circuit is further configured to identify a first set of mobile terminals from the one or more mobile terminals that are assigned radio resources during coinciding downlink and uplink periods relative to the first TDD schedule and identifying a second set of mobile terminals from the one or more mobile terminals that are assigned radio resources during opposing downlink and uplink periods relative to the first TDD schedule, and determine the resource allocation for the one or more mobile terminals by assigning radio resources to the first set of mobile terminals that occur during opposing downlink and uplink subframes relative to the first TDD schedule and by assigning radio resources to the second set of mobile terminals that occur during coinciding downlink and uplink subframes relative to the first TDD schedule.

[0138] In Example 27, the subject matter of any one of Examples 15 to 26 can optionally include wherein the schedule control circuit is further configured to communicate with the plurality of mobile terminals according to a third TDD schedule prior to selecting the second TDD schedule.

[0139] In Example 28, the subject matter of Example 27 can optionally include wherein the interference measurements characterize radio conditions experienced by the plurality of mobile terminals while operating according to the third TDD schedule.

[0140] Example 29 is a method of managing interference, the method including estimating a first time division duplexing (TDD) schedule of an interfering base station, evaluating interference measurements provided by a plurality of mobile terminals to identify one or more interfered mobile terminals, selecting a second TDD schedule with a target amount of coinciding downlink and uplink periods and a target amount of opposing downlink and uplink periods relative to the first TDD schedule based on the one or more interfered mobile terminals, and transmitting a resource allocation to the plurality of mobile terminals according to the second TDD schedule.

[0141] In Example 30, the subject matter of Example 29 can optionally include wherein estimating the first TDD schedule of the interfering base station includes receiving measurement reports from one or more measurement nodes, and estimating the first TDD schedule based on the measurement reports.

[0142] In Example 31, the subject matter of Example 30 can optionally include wherein the one or more measurement nodes are mobile terminals of the plurality of mobile terminals.

[0143] In Example 32, the subject matter of any one of Examples 29 to 31 can optionally include wherein estimating the first TDD schedule of the interfering base station includes identifying a TDD schedule from a predefined set of TDD schedules as the first TDD schedule.

[0144] In Example 33, the subject matter of any one of Examples 29 to 31 can optionally include wherein estimating the first TDD schedule of the interfering base station includes identifying estimated downlink and uplink periods of the interfering base station based on measurement reports received from one or more of the plurality of mobile terminals, and identifying a TDD schedule from a predefined set of TDD schedules that matches with the estimated downlink and uplink periods as the first TDD schedule.

[0145] In Example 34, the subject matter of any one of Examples 29 to 33 can optionally further include identifying a first set of mobile terminals from the one or more interfered mobile terminals that are assigned radio resources during coinciding downlink and uplink periods relative to the first TDD schedule and identifying a second set of mobile terminals from the one or more interfered mobile terminals that are assigned radio resources during opposing downlink and uplink periods relative to the first TDD schedule, and selecting the target amount of coinciding downlink and uplink periods and the target amount of opposing downlink and uplink periods based on the first set of mobile terminals and the second set of mobile terminals.

[0146] In Example 35, the subject matter of Example 34 can optionally include wherein selecting the target amount of coinciding downlink and uplink periods and the target amount of opposing downlink and uplink periods based on the first set of mobile terminals and the second set of mobile terminals includes selecting a higher target amount of opposing downlink and uplink periods than the target amount of coinciding downlink and uplink periods if the first set of mobile terminals is larger than the second set of mobile terminals, and selecting a higher target amount of coinciding downlink and uplink periods than the target amount of opposing downlink and uplink periods if the second set of mobile terminals is larger than the first set of mobile terminals.

[0147] In Example 36, the subject matter of any one of Examples 29 to 33 can optionally further include identifying a first set of mobile terminals from the one or more interfered mobile terminals that are assigned radio resources during coinciding downlink and uplink periods relative to the first TDD schedule and identifying a second set of mobile terminals from the one or more interfered mobile terminals that are assigned radio resources during opposing downlink and uplink periods relative to the first TDD schedule, and selecting a higher target amount of coinciding downlink and uplink periods relative to the first TDD schedule if the first set of mobile terminals is smaller than the second set of mobile terminals.

[0148] In Example 37, the subject matter of any one of Examples 29 to 33 can optionally further include identifying a first set of mobile terminals from the one or more interfered mobile terminals that are assigned radio resources during coinciding downlink and uplink periods relative to the first TDD schedule and identifying a second set of mobile terminals from the one or more interfered mobile terminals that are assigned radio resources during opposing downlink and uplink periods relative to the first TDD schedule, and selecting a higher target amount of opposing downlink and uplink periods relative to the first TDD schedule if the first set of mobile terminals is larger than the second set of mobile terminals.

[0149] In Example 38, the subject matter of Example 29 can optionally include wherein transmitting the resource allocation to the plurality of mobile terminals includes assigning each of the plurality of mobile terminals to perform downlink and uplink communications according to the second TDD schedule.

[0150] In Example 39, the subject matter of any one of Examples 29 to 33 can optionally further include identifying a first set of mobile terminals from the one or more interfered mobile terminals that are assigned radio resources during coinciding downlink and uplink periods relative to the first TDD schedule and identifying a second set of mobile terminals from the one or more interfered mobile terminals that are assigned radio resources during opposing downlink and uplink periods relative to the first TDD schedule, and determining the resource allocation for the plurality of mobile terminals by assigning radio resources to the first set of mobile terminals that occur during opposing downlink and uplink subframes relative to the first TDD schedule and by assigning radio resources to the second set of mobile terminals that occur during coinciding downlink and uplink subframes relative to the first TDD schedule.

[0151] In Example 40, the subject matter of any one of Examples 29 to 39 can optionally further include performing the method at a base station of a first Public Land Mobile Network (PLMN), wherein the interfering base station is not part of the first PLMN.

[0152] In Example 41, the subject matter of any one of Examples 29 to 40 can optionally further include communicating with the plurality of mobile terminals according to a third TDD schedule prior to selecting the second TDD schedule.

[0153] In Example 42, the subject matter of Example 41 can optionally include wherein the interference measurements characterize radio conditions experienced by the plurality of mobile terminals while operating according to the third TDD schedule. [0154] In Example 43, the subject matter of Example 41 can optionally include wherein the third TDD schedule is not synchronized in time on a subframe level with the second TDD schedule.

[0155] In Example 44, the subject matter of any one of Examples 29 to 43 can optionally include wherein the second TDD schedule is synchronized in time on a subframe level with the second TDD schedule.

[0156] In Example 45, the subject matter of any one of Examples 29 to 44 can optionally include wherein estimating the first TDD schedule of the interfering base station includes unilaterally estimating the first TDD schedule of the interfering base station.

[0157] In Example 46, the subject matter of any one of Examples 29 to 45 can optionally include wherein estimating the first TDD schedule of the interfering base station includes estimating the first TDD schedule by an operation other than receiving the first TDD schedule directly from the interfering base station.

[0158] In Example 47, the subject matter of any one of Examples 29 to 46 can optionally further include communicating with the plurality of mobile terminals according to the resource allocation.

[0159] In Example 48, the subject matter of any one of Examples 29 to 46 can optionally further include communicating with the plurality of mobile terminals according to the resource allocation using spectrum licensed with a spectrum sharing system.

[0160] In Example 49, the subject matter of Example 48 can optionally include wherein the spectrum sharing system is a Licensed Shared Access (LSA) or Spectrum Access System (SAS) system.

[0161] Example 50 is a non-transitory computer readable medium storing instructions that when executed by a processor direct the processor to perform the method of any one of Examples 29 to 50. [0162] Example 51 is a base station configured to perform the method of any one of Examples 29 to 50.

[0163] Example 52 is a radio access node configured to perform the method of any one of Examples 29 to 50.

[0164] Example 53 is a control circuit configured to perform the method of any one of Examples 29 to 50.

[0165] Example 54 is a method of managing interference, the method including estimating a first time division duplexing (TDD) schedule of an interfering base station, based on radio conditions of one or more mobile terminals, selecting a second TDD schedule with a target amount of coinciding downlink and uplink periods and a target amount of opposing downlink and uplink periods relative to the first TDD schedule, and transmitting a resource allocation to the one or more mobile terminals according to the second TDD schedule.

[0166] In Example 55, the subject matter of Example 54 can optionally include wherein estimating the first TDD schedule of the interfering base station includes receiving measurement reports from one or more measurement nodes, and estimating the first TDD schedule based on the measurement reports.

[0167] In Example 56, the subject matter of Example 55 can optionally include wherein the one or more measurement nodes are mobile terminals of the plurality of mobile terminals.

[0168] In Example 57, the subject matter of any one of Examples 54 to 56 can optionally include wherein estimating the first TDD schedule of the interfering base station includes identifying a TDD schedule from a predefined set of TDD schedules as the first TDD schedule.

[0169] In Example 58, the subject matter of any one of Examples 54 to 57 can optionally include wherein estimating the first TDD schedule of the interfering base station includes identifying estimated downlink and uplink periods of the interfering base station based on measurement reports received from one or more of the plurality of mobile terminals, and identifying a TDD schedule from a predefined set of TDD schedules that matches with the estimated downlink and uplink periods as the first TDD schedule.

[0170] In Example 59, the subject matter of any one of Examples 54 to 58 can optionally include wherein selecting the second TDD schedule with the target amount of coinciding downlink and uplink periods and the target amount of opposing downlink and uplink periods relative to the first TDD schedule includes receiving interference measurements from the one or more mobile terminals, and selecting the second TDD schedule based on the interference measurements.

[0171] In Example 60, the subject matter of Example 59 can optionally further include identifying one or more interfered mobile terminals from the one or more mobile terminals that experience excessive interference based on the interference measurements, identifying a first set of mobile terminals from the one or more interfered mobile terminals that are assigned radio resources during coinciding downlink and uplink periods relative to the first TDD schedule and identifying a second set of mobile terminals from the one or more interfered mobile terminals that are assigned radio resources during opposing downlink and uplink periods relative to the first TDD schedule, and selecting the target amount of coinciding downlink and uplink periods and the target amount of opposing downlink and uplink periods based on the first set of mobile terminals and the second set of mobile terminals.

[0172] In Example 61, the subject matter of Example 60 can optionally include wherein selecting the target amount of coinciding downlink and uplink periods and the target amount of opposing downlink and uplink periods based on the first set of mobile terminals and the second set of mobile terminals includes selecting a higher target amount of opposing downlink and uplink periods than the target amount of coinciding downlink and uplink periods if the first set of mobile terminals is larger than the second set of mobile terminals, and selecting a higher target amount of coinciding downlink and uplink periods than the target amount of opposing downlink and uplink periods if the second set of mobile terminals is larger than the first set of mobile terminals.

[0173] In Example 62, the subject matter of Example 59 can optionally further include identifying one or more interfered mobile terminals from the one or more mobile terminals that experience excessive interference based on the interference measurements, identifying a first set of mobile terminals from the one or more interfered mobile terminals that are assigned radio resources during coinciding downlink and uplink periods relative to the first

TDD schedule and identifying a second set of mobile terminals from the one or more interfered mobile terminals that are assigned radio resources during opposing downlink and uplink periods relative to the first TDD schedule, and selecting a higher target amount of coinciding downlink and uplink periods relative to the first TDD schedule if the first set of mobile terminals is smaller than the second set of mobile terminals.

[0174] In Example 63, the subject matter of Example 59 can optionally further include identifying one or more interfered mobile terminals from the one or more mobile terminals that experience excessive interference based on the interference measurements, identifying a first set of mobile terminals from the one or more interfered mobile terminals that are assigned radio resources during coinciding downlink and uplink periods relative to the first

TDD schedule and identifying a second set of mobile terminals from the one or more interfered mobile terminals that are assigned radio resources during opposing downlink and uplink periods relative to the first TDD schedule, and selecting a higher target amount of opposing downlink and uplink periods relative to the first TDD schedule if the first set of mobile terminals is larger than the second set of mobile terminals.

[0175] In Example 64, the subject matter of Example 59 can optionally further include identifying one or more interfered mobile terminals from the one or more mobile terminals that experience excessive interference based on the interference measurements, identifying a first set of mobile terminals from the one or more interfered mobile terminals that are assigned radio resources during coinciding downlink and uplink periods relative to the first TDD schedule and identifying a second set of mobile terminals from the one or more interfered mobile terminals that are assigned radio resources during opposing downlink and uplink periods relative to the first TDD schedule, and determining the resource allocation for the one or more of mobile terminals by assigning radio resources to the first set of mobile terminals that occur during opposing downlink and uplink subframes relative to the first TDD schedule and by assigning radio resources to the second set of mobile terminals that occur during coinciding downlink and uplink subframes relative to the first TDD schedule.

[0176] In Example 65, the subject matter of any one of Examples 54 to 64 can optionally include wherein transmitting the resource allocation to the one or more mobile terminals includes assigning each of the one or more mobile terminals to perform downlink and uplink communications according to the second TDD schedule.

[0177] In Example 66, the subject matter of any one of Examples 54 to 65 can optionally further include performing the method at a base station of a first Public Land Mobile Network (PLMN), wherein the interfering base station is not part of the first PLMN.

[0178] In Example 67, the subject matter of any one of Examples 54 to 66 can optionally further include communicating with the plurality of mobile terminals according to a third TDD schedule prior to selecting the second TDD schedule.

[0179] In Example 68, the subject matter of Example 67 can optionally include wherein selecting the second TDD schedule with the target amount of coinciding downlink and uplink periods and the target amount of opposing downlink and uplink periods relative to the first TDD schedule includes selecting the second TDD schedule based on interference conditions experienced by the one or more mobile terminals while operating according to the third TDD schedule. [0180] In Example 69, the subject matter of Example 67 can optionally include wherein the third TDD schedule is not synchronized in time on a subframe level with the second TDD schedule.

[0181] In Example 70, the subject matter of any one of Examples 54 to 69 can optionally include wherein the second TDD schedule is synchronized in time on a subframe level with the second TDD schedule.

[0182] In Example 71, the subject matter of any one of Examples 54 to 70 can optionally include wherein estimating the first TDD schedule of the interfering base station includes unilaterally estimating the first TDD schedule.

[0183] In Example 72, the subject matter of any one of Examples 54 to 71 can optionally include wherein estimating the first TDD schedule of the interfering base station includes estimating the first TDD schedule by an operation other than receiving the first TDD schedule directly from the interfering base station.

[0184] In Example 73, the subject matter of any one of Examples 54 to 72 can optionally further include communicating with the plurality of mobile terminals according to the resource allocation.

[0185] In Example 74, the subject matter of any one of Examples 54 to 73 can optionally further include communicating with the plurality of mobile terminals according to the resource allocation with shared spectrum of a spectrum sharing system.

[0186] In Example 75, the subject matter of Example 74 can optionally include wherein the spectrum sharing system is a Licensed Shared Access (LSA) or Spectrum Access System (SAS) system.

[0187] Example 76 is a non-transitory computer readable medium storing instructions that when executed by a processor direct the processor to perform the method of any one of Examples 54 to 75. [0188] Example 77 is a base station configured to perform the method of any one of Examples 54 to 75.

[0189] Example 78 is a radio access node configured to perform the method of any one of Examples 54 to 75.

[0190] Example 79 is a control circuit configured to perform the method of any one of Examples 54 to 75.

[0191] Example 80 is a radio access node including a schedule control circuit configured to estimate a first time division duplexing (TDD) schedule of an interfering base station, evaluate interference measurements provided by a plurality of mobile terminals to identify one or more interfered mobile terminals, select a second TDD schedule with a target amount of coinciding downlink and uplink periods and a target amount of opposing downlink and uplink periods relative to the first TDD schedule based on the one or more interfered mobile terminals, and transmit a resource allocation to the plurality of mobile terminals according to the second TDD schedule.

[0192] In Example 81, the subject matter of Example 80 can optionally further include a baseband processing circuit configured to manage radio communications with the plurality of mobile terminals.

[0193] In Example 82, the subject matter of Example 80 or 81 can optionally include wherein schedule control circuit is embodied as wired hardware circuitry.

[0194] In Example 83, the subject matter of Example 80 or 81 can optionally include wherein the schedule control circuit is embodied as a processor to execute programmable software instructions.

[0195] In Example 84, the subject matter of any one of Examples 80 to 83 can optionally further include a transceiver configured to communicate with the plurality of mobile terminals according to the resource allocation. [0196] In Example 85, the subject matter of any one of Examples 80 to 83 can optionally further include a transmitter, wherein the schedule control circuit is configured to transmit the resource allocation to the plurality of mobile terminals with the transmitter.

[0197] In Example 86, the subject matter of any one of Examples 80 to 83 can optionally further include a transceiver configured to communicate with the plurality of mobile terminals according to the resource allocation with shared spectrum of a spectrum sharing system.

[0198] In Example 87, the subject matter of Example 86 can optionally include wherein the spectrum sharing system is a Licensed Shared Access (LSA) or Spectrum Access System (SAS) system.

[0199] In Example 88, the subject matter of any one of Examples 80 to 87 can optionally include embodied as a base station of a cellular communication network.

[0200] In Example 89, the subject matter of any one of Examples 80 to 87 can optionally include embodied within a core network of a cellular communication network.

[0201] In Example 90, the subject matter of any one of Examples 80 to 89 can optionally include wherein the schedule control circuit is configured to estimate the first TDD schedule of the interfering base station by receiving measurement reports from one or more

measurement nodes, and estimating the first TDD schedule based on the measurement reports.

[0202] In Example 91, the subject matter of Example 90 can optionally include wherein the one or more measurement nodes are mobile terminals of the plurality of mobile terminals.

[0203] In Example 92, the subject matter of any one of Examples 80 to 91 can optionally include wherein the schedule control circuit is configured to estimate the first TDD schedule of the interfering base station by identifying a TDD schedule from a predefined set of TDD schedules as the first TDD schedule.

[0204] In Example 93, the subject matter of any one of Examples 80 to 91 can optionally include wherein the schedule control circuit is configured to estimate the first TDD schedule of the interfering base station by identifying estimated downlink and uplink periods of the interfering base station based on measurement reports received from one or more of the plurality of mobile terminals, and identifying a TDD schedule from a predefined set of TDD schedules that matches with the estimated downlink and uplink periods as the first TDD schedule.

[0205] In Example 94, the subject matter of any one of Examples 80 to 93 can optionally include wherein the schedule control circuit is further configured to identify a first set of mobile terminals from the one or more interfered mobile terminals that are assigned radio resources during coinciding downlink and uplink periods relative to the first TDD schedule and identifying a second set of mobile terminals from the one or more interfered mobile terminals that are assigned radio resources during opposing downlink and uplink periods relative to the first TDD schedule, and selecting the target amount of coinciding downlink and uplink periods and the target amount of opposing downlink and uplink periods based on the first set of mobile terminals and the second set of mobile terminals.

[0206] In Example 95, the subject matter of Example 94 can optionally include wherein the schedule control circuit is configured to select the target amount of coinciding downlink and uplink periods and the target amount of opposing downlink and uplink periods based on the first set of mobile terminals and the second set of mobile terminals by selecting a higher target amount of opposing downlink and uplink periods than the target amount of coinciding downlink and uplink periods if the first set of mobile terminals is larger than the second set of mobile terminals, and selecting a higher target amount of coinciding downlink and uplink periods than the target amount of opposing downlink and uplink periods if the second set of mobile terminals is larger than the first set of mobile terminals.

[0207] In Example 96, the subject matter of any one of Examples 80 to 93 can optionally include wherein the schedule control circuit is further configured to identify a first set of mobile terminals from the one or more interfered mobile terminals that are assigned radio resources during coinciding downlink and uplink periods relative to the first TDD schedule and identifying a second set of mobile terminals from the one or more interfered mobile terminals that are assigned radio resources during opposing downlink and uplink periods relative to the first TDD schedule, and select a higher target amount of coinciding downlink and uplink periods relative to the first TDD schedule if the first set of mobile terminals is smaller than the second set of mobile terminals.

[0208] In Example 97, the subject matter of any one of Examples 80 to 93 can optionally include wherein the schedule control circuit is further configured to identify a first set of mobile terminals from the one or more interfered mobile terminals that are assigned radio resources during coinciding downlink and uplink periods relative to the first TDD schedule and identifying a second set of mobile terminals from the one or more interfered mobile terminals that are assigned radio resources during opposing downlink and uplink periods relative to the first TDD schedule, and select a higher target amount of opposing downlink and uplink periods relative to the first TDD schedule if the first set of mobile terminals is larger than the second set of mobile terminals.

[0209] In Example 98, the subject matter of any one of Examples 80 to 97 can optionally include wherein the schedule control circuit is configured to transmit the resource allocation to the plurality of mobile terminals by assigning each of the plurality of mobile terminals to perform downlink and uplink communications according to the second TDD schedule.

[0210] In Example 99, the subject matter of any one of Examples 80 to 93 can optionally include wherein the schedule control circuit is further configured to identify a first set of mobile terminals from the one or more interfered mobile terminals that are assigned radio resources during coinciding downlink and uplink periods relative to the first TDD schedule and identifying a second set of mobile terminals from the one or more interfered mobile terminals that are assigned radio resources during opposing downlink and uplink periods relative to the first TDD schedule, and determine the resource allocation for the plurality of mobile terminals by assigning radio resources to the first set of mobile terminals that occur during opposing downlink and uplink subframes relative to the first TDD schedule and by assigning radio resources to the second set of mobile terminals that occur during coinciding downlink and uplink subframes relative to the first TDD schedule.

[0211] In Example 100, the subject matter of any one of Examples 80 to 99 can optionally include wherein the schedule control circuit is further configured to control downlink and uplink scheduling for a base station of a first Public Land Mobile Network (PLMN), wherein the interfering base station is not part of the first PLMN.

[0212] In Example 101, the subject matter of any one of Examples 80 to 100 can optionally include wherein the schedule control circuit is further configured to communicate with the plurality of mobile terminals according to a third TDD schedule prior to selecting the second TDD schedule.

[0213] In Example 102, the subject matter of Example 101 can optionally include wherein the interference measurements characterize radio conditions experienced by the plurality of mobile terminals while operating according to the third TDD schedule.

[0214] In Example 103, the subject matter of Example 101 can optionally include wherein the third TDD schedule is not synchronized in time on a subframe level with the second TDD schedule.

[0215] In Example 104, the subject matter of any one of Examples 80 to 103 can optionally include wherein the second TDD schedule is synchronized in time on a subframe level with the second TDD schedule.

[0216] In Example 105, the subject matter of any one of Examples 80 to 104 can optionally include wherein the schedule control circuit is configured to estimate the first TDD schedule of the interfering base station by unilaterally estimating the first TDD schedule of the interfering base station.

[0217] In Example 106, the subject matter of any one of Examples 80 to 105 can optionally include wherein the schedule control circuit is configured to estimate the first TDD schedule of the interfering base station by estimating the first TDD schedule by an operation other than receiving the first TDD schedule directly from the interfering base station.

[0218] Example 107 is a radio access node including a schedule control circuit configured to estimate a first time division duplexing (TDD) schedule of an interfering base station, based on radio conditions of one or more mobile terminals, select a second TDD schedule with a target amount of coinciding downlink and uplink periods and a target amount of opposing downlink and uplink periods relative to the first TDD schedule, and transmit a resource allocation to the one or more mobile terminals according to the second TDD schedule.

[0219] In Example 108, the subject matter of Example 107 can optionally further include a baseband processing circuit configured to manage radio communications with a plurality of mobile terminals.

[0220] In Example 109, the subject matter of Example 107 or 108 can optionally include wherein schedule control circuit is embodied as wired hardware circuitry.

[0221] In Example 110, the subject matter of Example 107 or 108 can optionally include wherein the schedule control circuit is embodied as a processor to execute programmable software instructions.

[0222] In Example 111 , the subj ect matter of any one of Examples 107 to 110 can optionally further include a transmitter, wherein the schedule control circuit is configured to transmit the resource allocation to the plurality of mobile terminals with the transmitter.

[0223] In Example 112, the subj ect matter of any one of Examples 107 to 110 can optionally further include a transceiver configured to communicate with the plurality of mobile terminals according to the resource allocation.

[0224] In Example 113, the subj ect matter of any one of Examples 107 to 110 can optionally further include a transceiver configured to communicate with the plurality of mobile terminals according to the receiver allocation with shared spectrum of a spectrum sharing system. [0225] In Example 114, the subj ect matter of Example 113 can optionally include wherein the spectrum sharing system is a Licensed Shared Access (LSA) or Spectrum Access System (SAS) system.

[0226] In Example 115, the subject matter of any one of Examples 107 to 114 can optionally include embodied as a base station of a cellular communication network.

[0227] In Example 116, the subject matter of any one of Examples 107 to 114 can optionally include embodied within a core network of a cellular communication network.

[0228] In Example 117, the subj ect matter of any one of Examples 107 to 116 can optionally include wherein the schedule control circuit is configured to estimate the first TDD schedule of the interfering base station by receiving measurement reports from one or more

[0229] In Example 118, the subj ect matter of Example 117 can optionally include wherein the one or more measurement nodes are mobile terminals of the plurality of mobile terminals.

[0230] In Example 119, the subject matter of any one of Examples 107 to 118 can optionally include wherein the schedule control circuit is configured to estimate the first TDD schedule of the interfering base station by identifying a TDD schedule from a predefined set of TDD schedules as the first TDD schedule.

[0231] In Example 120, the subject matter of any one of Examples 107 to 118 can optionally include wherein the schedule control circuit is configured to estimate the first TDD schedule of the interfering base station by identifying estimated downlink and uplink periods of the interfering base station based on measurement reports received from one or more of the plurality of mobile terminals, and identifying a TDD schedule from a predefined set of TDD schedules that matches with the estimated downlink and uplink periods as the first TDD schedule.

[0232] In Example 121, the subject matter of any one of Examples 107 to 120 can optionally include wherein the schedule control circuit is configured to select the second TDD schedule with the target amount of coinciding downlink and uplink periods and the target amount of opposing downlink and uplink periods relative to the first TDD schedule by receiving interference measurements from the one or more mobile terminals, and selecting the second TDD schedule based on the interference measurements.

[0233] In Example 122, the subject matter of Example 121 can optionally include wherein the schedule control circuit is further configured to identify one or more interfered mobile terminals from the one or more mobile terminals that experience excessive interference based on the interference measurements, identify a first set of mobile terminals from the one or more interfered mobile terminals that are assigned radio resources during coinciding downlink and uplink periods relative to the first TDD schedule and identify a second set of mobile terminals from the one or more interfered mobile terminals that are assigned radio resources during opposing downlink and uplink periods relative to the first TDD schedule, and select the target amount of coinciding downlink and uplink periods and the target amount of opposing downlink and uplink periods based on the first set of mobile terminals and the second set of mobile terminals.

[0234] In Example 123, the subject matter of Example 122 can optionally include wherein the schedule control circuit is configured to select the target amount of coinciding downlink and uplink periods and the target amount of opposing downlink and uplink periods based on the first set of mobile terminals and the second set of mobile terminals by selecting a higher target amount of opposing downlink and uplink periods than the target amount of coinciding downlink and uplink periods if the first set of mobile terminals is larger than the second set of mobile terminals, and selecting a higher target amount of coinciding downlink and uplink periods than the target amount of opposing downlink and uplink periods if the second set of mobile terminals is larger than the first set of mobile terminals.

[0235] In Example 124, the subject matter of Example 121 can optionally include wherein the schedule control circuit is further configured to identify one or more interfered mobile terminals from the one or more mobile terminals that experience excessive interference based on the interference measurements, identify a first set of mobile terminals from the one or more interfered mobile terminals that are assigned radio resources during coinciding downlink and uplink periods relative to the first TDD schedule and identifying a second set of mobile terminals from the one or more interfered mobile terminals that are assigned radio resources during opposing downlink and uplink periods relative to the first TDD schedule, and select a higher target amount of coinciding downlink and uplink periods relative to the first TDD schedule if the first set of mobile terminals is smaller than the second set of mobile terminals.

[0236] In Example 125, the subject matter of Example 121 can optionally include wherein the schedule control circuit is further configured to identify one or more interfered mobile terminals from the one or more mobile terminals that experience excessive interference based on the interference measurements, identify a first set of mobile terminals from the one or more interfered mobile terminals that are assigned radio resources during coinciding downlink and uplink periods relative to the first TDD schedule and identifying a second set of mobile terminals from the one or more interfered mobile terminals that are assigned radio resources during opposing downlink and uplink periods relative to the first TDD schedule, and select a higher target amount of opposing downlink and uplink periods relative to the first TDD schedule if the first set of mobile terminals is larger than the second set of mobile terminals.

[0237] In Example 126, the subject matter of Example 121 can optionally include wherein the schedule control circuit is further configured to identify one or more interfered mobile terminals from the one or more mobile terminals that experience excessive interference based on the interference measurements, identify a first set of mobile terminals from the one or more interfered mobile terminals that are assigned radio resources during coinciding downlink and uplink periods relative to the first TDD schedule and identifying a second set of mobile terminals from the one or more interfered mobile terminals that are assigned radio resources during opposing downlink and uplink periods relative to the first TDD schedule, and determine the resource allocation for the one or more of mobile terminals by assigning radio resources to the first set of mobile terminals that occur during opposing downlink and uplink subframes relative to the first TDD schedule and by assigning radio resources to the second set of mobile terminals that occur during coinciding downlink and uplink subframes relative to the first TDD schedule.

[0238] In Example 127, the subject matter of any one of Examples 107 to 126 can optionally include wherein the schedule control circuit is configured to transmit the resource allocation to the one or more mobile terminals by assigning each of the one or more mobile terminals to perform downlink and uplink communications according to the second TDD schedule.

[0239] In Example 128, the subject matter of any one of Examples 107 to 127 can optionally include wherein the schedule control circuit is further configured to control downlink and uplink scheduling for a base station of a first Public Land Mobile Network (PLMN), wherein the interfering base station is not part of the first PLMN.

[0240] In Example 129, the subject matter of any one of Examples 107 to 128 can optionally include wherein the schedule control circuit is further configured to communicate with the plurality of mobile terminals according to a third TDD schedule prior to selecting the second TDD schedule.

[0241] In Example 130, the subject matter of Example 129 can optionally include wherein the schedule control circuit is configured to select the second TDD schedule with the target amount of coinciding downlink and uplink periods and the target amount of opposing downlink and uplink periods relative to the first TDD schedule by selecting the second TDD schedule based on interference conditions experienced by the one or more mobile terminals while operating according to the third TDD schedule

[0242] In Example 131, the subject matter of Example 129 can optionally include wherein the third TDD schedule is not synchronized in time on a subframe level with the second TDD schedule. [0243] In Example 132, the subject matter of any one of Examples 107 to 131 can optionally include wherein the second TDD schedule is synchronized in time on a subframe level with the second TDD schedule.

[0244] In Example 133, the subject matter of any one of Examples 107 to 132 can optionally include wherein the schedule control circuit is configured to estimate the first TDD schedule of the interfering base station by unilaterally estimating the first TDD schedule of the interfering base station.

[0245] In Example 134, the subject matter of any one of Examples 107 to 133 can optionally include wherein the schedule control circuit is configured to estimate the first TDD schedule of the interfering base station by estimating the first TDD schedule by an operation other than receiving the first TDD schedule directly from the interfering base station.

[0246] Example 135 is a method for performing radio communications at a mobile terminal, the method including communicating with a serving base station according to a first time division duplexing (TDD) schedule, transmitting radio measurements to the serving base station, wherein the radio measurements indicate whether the mobile terminal is better suited for coinciding downlink and uplink periods or opposing downlink and uplink periods relative to an interfering base station, and if the radio measurements indicate that the mobile terminal is better suited for coinciding downlink and uplink periods relative to the interfering base station, receiving a resource allocation for a second TDD schedule that assigns the mobile terminal radio resources that occur during coinciding downlink and uplink periods relative to the interfering base station.

[0247] In Example 136, the subject matter of Example 135 can optionally include where the second TDD schedule has differing downlink and uplink periods than the first TDD schedule.

[0248] In Example 137, the subject matter of Example 135 or 136 can optionally further include performing the radio measurements. [0249] In Example 138, the subject matter of any one of Examples 135 to 137 can optionally further include communicating with the serving base station according to the second TDD schedule.

[0250] In Example 139, the subject matter of Example 138 can optionally include wherein communicating with the serving base station according to the second TDD schedule includes communicating with the serving base station with shared spectrum of a spectrum sharing scheme.

[0251] In Example 140, the subject matter of Example 139 can optionally include wherein the spectrum sharing scheme is a Licensed Shared Access (LSA) or Spectrum Access System (SAS) scheme.

[0252] In Example 141, the subject matter of any one of Examples 135 to 140 can optionally include wherein the second TDD schedule is synchronized in time on a subframe level with the first TDD schedule.

[0253] In Example 142, the subject matter of any one of Examples 135 to 140 can optionally include wherein the second TDD schedule is not synchronized in time on a subframe level with the first TDD schedule.

[0254] In Example 143, the subject matter of any one of Examples 135 to 142 can optionally include wherein the interfering base station is not part of the same Public Land Mobile Network (PLMN) as the mobile terminal.

[0255] In Example 144, the subject matter of any one of Examples 135 to 143 can optionally include wherein one or more of the first TDD schedule and the second TDD schedule are predefined TDD schedules of a predefined set of TDD schedules.

[0256] In Example 145, the subject matter of any one of Examples 135 to 144 can optionally further include if the radio measurements indicate that the mobile terminal is better suited for opposing downlink and uplink periods relative to the interfering base station, receiving a resource allocation for the second TDD schedule that assigns the mobile terminal radio resources that occur during opposing downlink and uplink periods relative to the interfering base station.

[0257] Example 146 is a non-transitory computer readable medium storing instructions that when executed by a processor direct the processor to perform the method of any one of Examples 135 to 145.

[0258] Example 147 is a mobile baseband circuit configured to perform the method of any one of Examples 135 to 145.

[0259] In Example 148, the subject matter of Example 147 can optionally include wherein the mobile baseband circuit is embodied as wired hardware circuitry.

[0260] In Example 149, the subject matter of Example 147 can optionally include wherein the mobile baseband circuit is embodied as a processor configured to execute programmable software instructions.

[0261] Example 150 is a mobile communication device including the mobile baseband circuit of any one of Examples 147 to 149.

[0262] Example 151 is a mobile communication device including a baseband processing circuit configured to communicate with a serving base station according to a first time division duplexing (TDD) schedule, and a radio transceiver configured to transmit radio measurements to the serving base station, wherein the radio measurements indicate whether the mobile terminal is better suited for coinciding downlink and uplink periods or opposing downlink and uplink periods relative to an interfering base station, and if the radio measurements indicate that the mobile terminal is better suited for coinciding downlink and uplink periods relative to the interfering base station, receive a resource allocation for a second TDD schedule that assigns the mobile terminal radio resources that occur during coinciding downlink and uplink periods relative to the interfering base station. [0263] In Example 152, the subject matter of Example 151 can optionally include wherein the second TDD schedule has differing downlink and uplink periods than the first TDD schedule.

[0264] In Example 153, the subject matter of Example 151 or 152 can optionally include wherein the baseband processing circuit is further configured to perform the radio measurements.

[0265] In Example 154, the subject matter of any one of Examples 151 to 153 can optionally include wherein the baseband processing circuit is further configured to communicate with the serving base station according to the second TDD schedule.

[0266] In Example 155, the subject matter of Example 154 can optionally include wherein the baseband processing circuit is configured to communicate with the serving base station according to the second TDD schedule by communicating with the serving base station with shared spectrum of a spectrum sharing scheme.

[0267] In Example 156, the subject matter of Example 155 can optionally include wherein the spectrum shared scheme is a Licensed Shared Access (LSA) or a Spectrum Access System (SAS) scheme.

[0268] In Example 157, the subject matter of any one of Examples 151 to 156 can optionally include wherein the second TDD schedule is synchronized in time on a subframe level with the first TDD schedule.

[0269] In Example 158, the subject matter of any one of Examples 151 to 156 can optionally include wherein the second TDD schedule is not synchronized in time on a subframe level with the first TDD schedule.

[0270] In Example 159, the subject matter of any one of Examples 151 to 158 can optionally include wherein the interfering base station is not part of the same Public Land Mobile Network (PLMN) as the mobile terminal. [0271] In Example 160, the subject matter of any one of Examples 151 to 159 can optionally include wherein one or more of the first TDD schedule and the second TDD schedule are predefined TDD schedules of a predefined set of TDD schedules.

[0272] In Example 161, the subject matter of any one of Examples 151 to 160 can optionally include wherein the radio transceiver is further configured to if the radio measurements indicate that the mobile terminal is better suited for opposing downlink and uplink periods relative to the interfering base station, receiving a resource allocation for the second TDD schedule that assigns the mobile terminal radio resources that occur during opposing downlink and uplink periods relative to the interfering base station.

[0273] All acronyms defined in the above description additionally hold in all claims included herein.

[0274] While the invention has been particularly shown and described with reference to specific embodiments, it should be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. The scope of the invention is thus indicated by the appended claims and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced.

Claims

Claims What is claimed is:

1. A radio access node comprising:

a schedule control circuit configured to:

identify interference caused by one or more transmitters of one or more lower service tiers to one or more mobile terminals, wherein the one or more mobile terminals relate to one or more other lower service tiers or one or more higher service tiers in a shared spectrum; estimate a first time division duplexing (TDD) schedule of the one or more lower service tiers;

select a second TDD schedule with a target amount of coinciding downlink and uplink periods and a target amount of opposing downlink and uplink periods relative to the first TDD schedule based on the identified interference from the one or more transmitters of the one or more lower service tiers; and

transmit a resource allocation to the one or more mobile terminals to use available spectrum according to the second TDD schedule.

2. The radio access node of claim 1, wherein the schedule control circuit is configured to estimate the first TDD schedule of the one or more lower service tiers by:

receiving measurement reports from one or more measurement nodes; and estimating the first TDD schedule based on the measurement reports.

3. The radio access node of claim 2, wherein the one or more measurement nodes comprise at least one of the one or more mobile terminals of the one or more other lower service tiers or the one or more higher service tiers in the shared spectrum.

4. The radio access node of any one of claims 1 to 3, wherein the schedule control circuit is configured to estimate the first TDD schedule of the one or more lower service tiers by: identifying estimated downlink and uplink periods of the one or more lower service tiers based on measurement reports received from at least one of the one or more mobile terminals; and

identifying a TDD schedule from a predefined set of TDD schedules that matches with the estimated downlink and uplink periods as the first TDD schedule.

5. The radio access node of any one of claims 1 to 3, wherein the schedule control circuit is further configured to:

identify a first set of mobile terminals from the one or more mobile terminals that are assigned radio resources during coinciding downlink and uplink periods relative to the first TDD schedule and identifying a second set of mobile terminals from the one or more mobile terminals that are assigned radio resources during opposing downlink and uplink periods relative to the first TDD schedule; and

selecting the target amount of coinciding downlink and uplink periods and the target amount of opposing downlink and uplink periods based on the first set of mobile terminals and the second set of mobile terminals.

6. The radio access node of claim 5, wherein the schedule control circuit is configured to select the target amount of coinciding downlink and uplink periods and the target amount of opposing downlink and uplink periods based on the first set of mobile terminals and the second set of mobile terminals by: selecting a higher target amount of opposing downlink and uplink periods than the target amount of coinciding downlink and uplink periods if the first set of mobile terminals is larger than the second set of mobile terminals; and

selecting a higher target amount of coinciding downlink and uplink periods than the target amount of opposing downlink and uplink periods if the second set of mobile terminals is larger than the first set of mobile terminals.

7. The radio access node of any one of claims 1 to 3, wherein the schedule control circuit is further configured to:

identify a first set of mobile terminals from the one or more mobile terminals that are assigned radio resources during coinciding downlink and uplink periods relative to the first TDD schedule and identifying a second set of mobile terminals from the one or more mobile terminals that are assigned radio resources during opposing downlink and uplink periods relative to the first TDD schedule; and determine the resource allocation for the one or more mobile terminals by assigning radio resources to the first set of mobile terminals that occur during opposing downlink and uplink subframes relative to the first TDD schedule and by assigning radio resources to the second set of mobile terminals that occur during coinciding downlink and uplink subframes relative to the first TDD schedule.

8. The radio access node of any one of claims 1 to 3, wherein the schedule control circuit is further configured to communicate with the one or more mobile terminals according to a third TDD schedule prior to selecting the second TDD schedule.

9. The radio access node of claim 8, wherein the identified interference characterize radio conditions experienced by the one or more mobile terminals while operating according to the third TDD schedule.

10. A method for managing interference used in mobile communication, the method comprising:

identifying interference caused by one or more transmitters of one or more lower service tiers to one or more mobile terminals, wherein the one or more mobile terminals relate to one or more other lower service tiers or one or more higher service tiers in a shared spectrum;

estimating a first time division duplexing (TDD) schedule of the one or more lower service tiers;

selecting a second TDD schedule with a target amount of coinciding downlink and uplink periods and a target amount of opposing downlink and uplink periods relative to the first TDD schedule based on the identified interference from the one or more transmitters of the one or more lower service tiers; and

transmitting a resource allocation to the one or more mobile terminals to use available spectrum according to the second TDD schedule.

11. The method of claim 10, further comprising:

identifying a first set of mobile terminals from the one or more mobile terminals that are assigned radio resources during coinciding downlink and uplink periods relative to the first TDD schedule and identifying a second set of mobile terminals from the one or more mobile terminals that are assigned radio resources during opposing downlink and uplink periods relative to the first TDD schedule; and selecting the target amount of coinciding downlink and uplink periods and the target amount of opposing downlink and uplink periods based on the first set of mobile terminals and the second set of mobile terminals.

12. The method of claim 10 or 11, further comprising:

identifying a first set of mobile terminals from the one or more mobile terminals that are assigned radio resources during coinciding downlink and uplink periods relative to the first TDD schedule and identifying a second set of mobile terminals from the one or more mobile terminals that are assigned radio resources during opposing downlink and uplink periods relative to the first TDD schedule; and

determining the resource allocation for the one or more mobile terminals by assigning radio resources to the first set of mobile terminals that occur during opposing downlink and uplink subframes relative to the first TDD schedule and by assigning radio resources to the second set of mobile terminals that occur during coinciding downlink and uplink subframes relative to the first TDD schedule.

13. A radio access node comprising:

a schedule control circuit configured to: estimate a first time division duplexing (TDD) schedule of an interfering base station; evaluate interference measurements provided by a plurality of mobile terminals to identify one or more interfered mobile terminals;

select a second TDD schedule with a target amount of coinciding downlink and uplink periods and a target amount of opposing downlink and uplink periods relative to the first TDD schedule based on the one or more interfered mobile terminals; and transmit a resource allocation to the plurality of mobile terminals according to the second TDD schedule.

14. The radio access node of claim 13, further comprising a transceiver configured to communicate with the plurality of mobile terminals according to the resource allocation with shared spectrum of a spectrum sharing system.

15. The radio access node of claim 13, wherein the schedule control circuit is configured to estimate the first TDD schedule of the interfering base station by:

16. The radio access node of claim 15, wherein the one or more measurement nodes are mobile terminals of the plurality of mobile terminals.

17. The radio access node of any one of claims 13 to 16, wherein the schedule control circuit is configured to estimate the first TDD schedule of the interfering base station by: identifying estimated downlink and uplink periods of the interfering base station based on measurement reports received from one or more of the plurality of mobile terminals; and identifying a TDD schedule from a predefined set of TDD schedules that matches with the estimated downlink and uplink periods as the first TDD schedule.

18. The radio access node of any one of claims 13 to 16, wherein the schedule control circuit is further configured to: identify a first set of mobile terminals from the one or more interfered mobile terminals that are assigned radio resources during coinciding downlink and uplink periods relative to the first TDD schedule and identifying a second set of mobile terminals from the one or more interfered mobile terminals that are assigned radio resources during opposing downlink and uplink periods relative to the first TDD schedule; and

19. The radio access node of claim 18, wherein the schedule control circuit is configured to select the target amount of coinciding downlink and uplink periods and the target amount of opposing downlink and uplink periods based on the first set of mobile terminals and the second set of mobile terminals by:

selecting a higher target amount of opposing downlink and uplink periods than the target amount of coinciding downlink and uplink periods if the first set of mobile terminals is larger than the second set of mobile terminals; and

20. The radio access node of any one of claims 13 to 16, wherein the schedule control circuit is further configured to:

identify a first set of mobile terminals from the one or more interfered mobile terminals that are assigned radio resources during coinciding downlink and uplink periods relative to the first TDD schedule and identifying a second set of mobile terminals from the one or more interfered mobile terminals that are assigned radio resources during opposing downlink and uplink periods relative to the first TDD schedule; and determine the resource allocation for the plurality of mobile terminals by assigning radio resources to the first set of mobile terminals that occur during opposing downlink and uplink subframes relative to the first TDD schedule and by assigning radio resources to the second set of mobile terminals that occur during coinciding downlink and uplink subframes relative to the first TDD schedule.

21. A method of managing interference, the method comprising:

estimating a first time division duplexing (TDD) schedule of an interfering base station;

evaluating interference measurements provided by a plurality of mobile terminals to identify one or more interfered mobile terminals;

selecting a second TDD schedule with a target amount of coinciding downlink and uplink periods and a target amount of opposing downlink and uplink periods relative to the first TDD schedule based on the one or more interfered mobile terminals; and

transmitting a resource allocation to the plurality of mobile terminals according to the second TDD schedule.

22. The method of claim 21, further comprising:

identifying a first set of mobile terminals from the one or more interfered mobile terminals that are assigned radio resources during coinciding downlink and uplink periods relative to the first TDD schedule and identifying a second set of mobile terminals from the one or more interfered mobile terminals that are assigned radio resources during opposing downlink and uplink periods relative to the first TDD schedule; and selecting the target amount of coinciding downlink and uplink periods and the target amount of opposing downlink and uplink periods based on the first set of mobile terminals and the second set of mobile terminals.

23. The method of claim 21, further comprising:

identifying a first set of mobile terminals from the one or more interfered mobile terminals that are assigned radio resources during coinciding downlink and uplink periods relative to the first TDD schedule and identifying a second set of mobile terminals from the one or more interfered mobile terminals that are assigned radio resources during opposing downlink and uplink periods relative to the first TDD schedule; and

determining the resource allocation for the plurality of mobile terminals by assigning radio resources to the first set of mobile terminals that occur during opposing downlink and uplink subframes relative to the first TDD schedule and by assigning radio resources to the second set of mobile terminals that occur during coinciding downlink and uplink subframes relative to the first TDD schedule.

24. A radio access node configured to perform the method of any one of claims 21 to 23.

25. A control circuit configured to perform the method of any one of claims 21 to 23.