BR112017012263B1 - METHOD AND EQUIPMENT FOR WIRELESS COMMUNICATION AND COMPUTER READABLE MEMORY - Google Patents

Abstract

INCORRECT DETECTION OF FRACTIONAL CHANNEL RESERVATION SIGNALS. Management of incorrect detection of fractional channel reservation signals is discussed. Fractional channel reservation signals may be incorrectly detected by receivers as regular channel reservation signals, resulting in inconsistencies between transmitters and receivers in performing uplink and downlink communication. Several aspects present solutions to this problem through different devices, such as the transmitter using a different sequence for fractional channel reservation signals, ensuring that the frame formatting signals are transmitted with the regular channel reservation signals, not transmitting such channels or not transmitting regular channel reservation signals after fractional signals are transmitted. Additionally, a transmitter may determine to discard one or more user equipment (UE) channel feedback reports when such fractional signals are transmitted. Additional aspects would have the UE monitor the last and first sub-frames for the channel reservation signals in order to determine which signal, if any, is the fractional reservation signal.

Description

CROSS REFERENCE TO RELATED ORDERS

[0001] This application claims the benefit of US provisional patent application No. 62/091,700, entitled “INCORRECT DETECTION OF FRACTIONAL CHANNEL RESERVATION SIGNALS”, filed on December 15, 2014, and the patent application of US Utility No. 14/968 462, entitled “INCORRECT DETECTION OF FRACTIONAL CHANNEL RESERVATION SIGNALS”, and filed on December 14, 2015, which are expressly incorporated herein by way of reference.

BACKGROUND Field

[0002] Aspects of the present disclosure relate generally to wireless communication systems and, more specifically, to the incorrect detection of fractional channel reservation signals in systems with contention-based spectrum sharing that includes unlicensed spectrum.

Background

[0003] Wireless communication networks are widely deployed to provide various communication services, such as voice, video, packet data, message exchange, broadcast, and the like. These wireless networks may be multiple access networks capable of supporting multiple users by sharing available network resources. Such networks, which are usually multiple access networks, support communications for multiple users by sharing available network resources. An example of such a network is the Universal Terrestrial Access Radio Network (UTRAN). UTRAN is the radio access network (RAN) defined as a part of the Universal Mobile Telecommunications System (UMTS), a third generation (3G) mobile telephone technology supported by the 3rd Partnership Project. Generation (3GPP). Examples of multiple access network formats include Code Division Multiple Access (CDMA) networks, Time Division Multiple Access (TDMA) networks, Frequency Division Multiple Access (FDMA) networks, Orthogonal FDMA (OFDMA) networks and Single Carrier FDMA (SC-FDMA) networks.

[0004] A wireless communications network may include multiple base stations with B nodes that may support communication to multiple user equipment (UEs). A UE can communicate with a base station via the downlink and uplink. The downlink (or forward link) refers to the communication link from the base station to the UE, and the uplink (or reverse link) refers to the communication link from the UE to the base station.

[0005] A base station may transmit data and control information in the downlink to a UE and/or may receive data and control information in the uplink from the UE. In downlink, a base station transmission may encounter interference due to transmissions from neighboring base stations or other wireless radio frequency (RF) transmitters. In the uplink, a UE transmission may encounter interference from uplink transmissions from other UEs communicating with neighboring base stations or from other wireless RF transmitters. This interference can deteriorate performance in both the downlink and uplink.

[0006] As the demand for mobile broadband access continues to increase, the possibilities for interference in congested networks grow with more UEs accessing long-range wireless communications networks and more short-range wireless systems being deployed in communities. Research and development continues to advance UMTS technologies to not only meet the growing demand for mobile broadband access, but also to advance and enhance the user experience with mobile communications.

SUMMARY

[0007] In one aspect of the disclosure, a method of wireless communication includes detecting, by a transmitter, a successful evaluation for extended channel release (ECCA) on at least one carrier using a contention-based radio frequency spectrum, in which the successful ECCA check before a boundary of the current subframe, partition or symbol, transmit, by the transmitter, a fractional channel reservation signal between the successful ECCA check and the subframe boundary in at least one carrier, in which the fractional channel reservation signal is generated using a first sequence, and transmitting by the transmitter a channel reservation signal that begins on the subsequent subframe after the current subframe on the at least one carrier, in the which channel reservation signal is generated using a second sequence different from the first sequence.

[0008] In a further aspect of the disclosure, a method of wireless communication includes detecting, by a transmitter, a successful ECCA check and the sub-frame boundary on the at least one carrier using a contention-based radio frequency spectrum, in which the successful ECCA check occurs before a boundary of the current subframe, partition, or symbol, and transmit, by the transmitter, a channel reservation signal that begins on the subsequent subframe after the current subframe in at least least one carrier.

[0009] In a further aspect of the disclosure, a wireless communication method includes monitoring, by a UE, a first sub-frame for channel reservation signals, monitoring, by the UE, the subsequent sub-frame for channel reservation signals. channel, and determining by the UE, whether a first channel reservation signal detected in the first sub-frame is a fractional channel reservation sub-frame when the UE detects the subsequent channel reservation signal in the subsequent sub-frame.

[0010] In a further aspect of the disclosure, a wireless communication method includes detecting, by a transmitter, a successful ECCA check on at least one carrier using a contention-based radio frequency spectrum, in which the successful ECCA check occurs before a current subframe, partition, or symbol boundary, transmit, by the transmitter, a fractional channel reservation signal between the successful ECCA check and the subframe boundary on the at least one carrier, and transmit , by the transmitter, data starting in the subsequent subframe after the current subframe on the at least one carrier.

[0011] In a further aspect of the disclosure, a wireless communication method includes detecting, by a transmitter, a successful ECCA check on at least one carrier utilizing a contention-based radio frequency spectrum, in which the successful ECCA check occurs before the boundary of the current subframe, partition, or symbol, transmit, by the transmitter, a fractional channel reservation signal between the successful ECCA check and the subframe boundary of the current subframe in at least one carrier, transmit, by the transmitter, a channel reservation signal that begins on the subsequent subframe after the current subframe of the at least one carrier, and transmit, by the transmitter, a frame format indicator signal in addition to the channel reservation signal in the subsequent sub-frame.

[0012] In a further aspect of the disclosure, a wireless communication method includes detecting, by a transmitter, a successful ECCA check on at least one carrier using a contention-based radio frequency spectrum, in which the successful ECCA check occurs before the boundary of the current subframe, partition, or symbol, transmit, by the transmitter, a fractional channel reservation signal between the successful ECCA check and the subframe boundary of the current subframe in at least one carrier, and discard, by the transmitter, each of one or more channel state information reports received by the transmitter in the subsequent subframe after the current subframe.

[0013] In a further aspect of the disclosure, equipment configured for wireless communication includes a device for detecting, by a transmitter, a successful ECCA check on at least one carrier utilizing a contention-based radio frequency spectrum, in which the successful ECCA check occurs before the current subframe, partition or symbol boundary, a device for transmitting, by the transmitter, a fractional channel reservation signal between the successful ECCA check and the subframe boundary at the at least one carrier, on which the fractional channel reservation signal is generated using a first sequence, and a device for transmitting, by the transmitter, a channel reservation signal starting in the subsequent sub-frame after the current sub-frame in the at least one carrier, in which the channel reservation signal is generated using a second sequence different from the first sequence.

[0014] In a further aspect of the disclosure, equipment configured for wireless communication includes a device for detecting, by a transmitter, a successful ECCA check on at least one carrier utilizing a contention-based radio frequency spectrum, in which the successful ECCA check occurs before the boundary of the current sub-frame, partition or symbol, and a device for transmitting, by the transmitter, a channel reservation signal starting in the subsequent sub-frame after the current sub-frame to at least one carrier.

[0015] Under a further aspect of the disclosure, an equipment configured for wireless communication includes a device for monitoring, by a UE, a first sub-frame for channel reservation signals, a device for monitoring, by the UE, the sub- subsequent frame for channel reservation signals, and a device for determining, by the UE, whether a first channel reservation signal decoded in the first subframe is a fractional channel reservation subframe when the UE detects the reservation signal channel in the subsequent subframe.

[0016] In a further aspect of the disclosure, equipment configured for wireless communication includes a device for detecting, by a transmitter, a successful ECCA check on at least one carrier utilizing a contention-based radio frequency spectrum, in which the successful ECCA check occurs before the current subframe, partition or symbol boundary, a device for transmitting, by the transmitter, a fractional channel reservation signal between the successful ECCA check and the subframe boundary at the at least one carrier, and a device for transmitting, by the transmitter, data starting on the subsequent subframe after the current subframe on the at least one carrier.

[0017] In a further aspect of the disclosure, equipment configured for wireless communication includes a device for detecting, by a transmitter, a successful ECCA check on at least one carrier utilizing a contention-based radio frequency spectrum, in which the successful ECCA check occurs before the current subframe, partition or symbol boundary, a device for transmitting, by the transmitter, a fractional channel reservation signal between the successful ECCA check and the subframe boundary at the at least one carrier, a device for transmitting, by the transmitter, a channel reservation signal starting on the subsequent subframe after the current subframe on the at least one carrier, and a device for transmitting, by the transmitter, a channel format indicator signal. frame in addition to the channel reservation signal in the subsequent subframe.

[0018] In a further aspect of the disclosure, equipment configured for wireless communication includes a device for detecting, by a transmitter, a successful ECCA check on at least one carrier utilizing a contention-based radio frequency spectrum, in which the successful ECCA check occurs before the boundary of the current subframe, partition or symbol, a device for transmitting, by the transmitter, a fractional channel reservation signal between the successful ECCA check and the subframe boundary in the sub - current frame on the at least one carrier, and a device for discarding, by the transmitter, each of one or more channel state information reports received by the transmitter in the subsequent sub-frame after the current sub-frame.

[0019] In a further aspect of the disclosure, a computer readable medium is disclosed that has a program code recorded therein. This program code includes code for detecting, by a transmitter, a successful ECCA check on at least one carrier using a contest-based radio frequency spectrum, in which the successful ECCA check occurs before the subframe boundary. , partition or current symbol, a code for transmitting, by the transmitter, a fractional channel reservation signal between the successful ECCA check and the subframe boundary on the at least one carrier, on which the fractional channel reservation signal is generated using the first sequence, and a code for transmitting, by the transmitter, a channel reservation signal starting in the subsequent subframe after the current subframe on the at least one carrier on which the channel reservation signal is generated using a second sequence different from the first sequence.

[0020] In a further aspect of the disclosure, a computer readable medium is disclosed that has a program code recorded therein. This program code includes code for detecting, by a transmitter, a successful ECCA check on at least one carrier using a contest-based radio frequency spectrum, in which the successful ECCA check occurs before the subframe boundary. , partition or current symbol, a code for transmitting, by the transmitter, a channel reservation signal starting in the subsequent subframe after the current subframe on the at least one carrier.

[0021] In a further aspect of the disclosure, a computer readable medium is disclosed that has a program code recorded therein. This program code includes a code for monitoring, by a UE, a first subframe for channel reservation signals, a code for monitoring, by the UE, the subsequent subframe for channel reservation signals, and a code for determining, by the UE, whether the first channel reservation signal detected in the first sub-frame is a fractional channel reservation sub-frame when the UE detects the subsequent channel reservation signal in the subsequent sub-frame.

[0022] In a further aspect of the disclosure, a computer readable medium is disclosed that has a program code recorded therein. This program code includes code for detecting, by a transmitter, a successful ECCA check on at least one carrier using a contest-based radio frequency spectrum, in which the successful ECCA check occurs before the subframe boundary. , partition or current symbol, a code for transmitting, by the transmitter, a fractional channel reservation signal between the successful ECCA check and the subframe boundary on the at least one carrier, and a code for transmitting, by the transmitter, data starting in the subsequent subframe after the current subframe on the at least one carrier.

[0023] In a further aspect of the disclosure, a computer readable medium is disclosed that has a program code recorded therein. This program code includes code for detecting, by a transmitter, a successful ECCA check on at least one carrier using a contest-based radio frequency spectrum, in which the successful ECCA check occurs before the subframe boundary. , partition or current symbol, a code for transmitting, by the transmitter, a fractional channel reservation signal between the successful ECCA check and the subframe boundary on the at least one carrier, and the subframe boundary of the sub -current frame on the at least one carrier m a code for transmitting, by the transmitter, a channel reservation signal starting in the subsequent subframe after the current subframe on the at least one carrier, and a code for transmitting, by the transmitter, a frame format indicator signal in addition to the channel reservation signal in the subsequent subframe.

[0024] In a further aspect of the disclosure, a computer readable medium is disclosed that has a program code recorded therein. This program code includes code for detecting, by a transmitter, a successful ECCA check on at least one carrier using a contest-based radio frequency spectrum, in which the successful ECCA check occurs before the subframe boundary. , partition or current symbol, a code for transmitting, by the transmitter, a fractional channel reservation signal between the successful ECCA check and the subframe boundary of the current subframe on the at least one carrier, and a code for transmitting, by the transmitter, each of one or more channel state information reports received by the transmitter of the subsequent sub-frame after the current sub-frame.

[0025] Under a further aspect of the disclosure, an equipment includes at least one processor and a memory coupled to the processor. The processor is configured to detect, by a transmitter, a successful ECCA check on at least one carrier using a contention-based radio frequency spectrum, in which the successful ECCA check occurs before the boundary of the subframe, partition or current symbol, to transmit, by the transmitter, a fractional channel reservation signal between the successful ECCA check and the subframe boundary on the at least one carrier, in which the fractional channel reservation signal is generated using a first sequence, and to transmit, by the transmitter, a channel reservation signal beginning in the subsequent subframe after the current subframe on the at least one carrier, in which the channel reservation signal is generated using a second sequence different from the first sequence.

[0026] Under a further aspect of the disclosure, an equipment includes at least one processor and a memory coupled to the processor. The processor is configured to detect, by a transmitter, a successful ECCA check on at least one carrier using a contention-based radio frequency spectrum, in which the successful ECCA check occurs before the boundary of the subframe, partition or current symbol, and to transmit, by the transmitter, a channel reservation signal that begins in the subsequent subframe after the current subframe on the at least one carrier.

[0027] Under a further aspect of the disclosure, an equipment includes at least one processor and a memory coupled to the processor. The processor is configured to monitor, by a UE, a first subframe for channel reservation signals, to monitor, by the UE, the subsequent subframe for channel reservation signals, and to determine, by the UE, whether the first channel reservation signal detected in the first sub-frame is a fractional channel reservation sub-frame when the UE detects the subsequent channel reservation signal in the subsequent sub-frame.

[0028] Under a further aspect of the disclosure, an equipment includes at least one processor and a memory coupled to the processor. The processor is configured to detect, by a transmitter, a successful ECCA check on at least one carrier using a contention-based radio frequency spectrum, in which the successful ECCA check occurs before the boundary of the subframe, partition or current symbol, to transmit, by the transmitter, a fractional channel reservation signal between the successful ECCA check and the subframe boundary on the at least one carrier, and to transmit, by the transmitter, data starting on the subsequent subframe deposed from the current sub-frame on at least one carrier.

[0029] Under a further aspect of the disclosure, an equipment includes at least one processor and a memory coupled to the processor. The processor is configured to detect, by a transmitter, a successful ECCA check on at least one carrier using a contention-based radio frequency spectrum, in which the successful ECCA check occurs before the boundary of the subframe, partition or current symbol, to transmit, by the transmitter, a fractional channel reservation signal between the successful ECCA check and the subframe boundary of the current subframe on the at least one carrier, to transmit, by the transmitter, a signal of channel reservation starting in the subsequent subframe after the current subframe on the at least one carrier, and to transmit, by the transmitter, a frame format indicator signal in addition to the channel reservation signal in the subsequent subframe.

[0030] Under a further aspect of the disclosure, an equipment includes at least one processor and a memory coupled to the processor. The processor is configured to detect, by a transmitter, a successful ECCA check on at least one carrier using a contention-based radio frequency spectrum, in which the successful ECCA check occurs before the boundary of the subframe, partition or current symbol, to transmit, by the transmitter, a fractional channel reservation signal between the successful ECCA check and the subframe boundary of the current subframe on the at least one carrier, and to discard, by the transmitter, each of one or more channel status information reports received by the person skilled in the art will recognize in the subsequent sub-frame after the current sub-frame.

BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 shows a diagram showing an example of a wireless communication system according to various embodiments.

[0032] Figure 2A shows a diagram showing example deployment scenarios for using LTE in an unlicensed spectrum according to various modalities.

[0033] Figure 2B shows a diagram showing another example deployment scenario for using LTE in an unlicensed spectrum according to various modalities.

[0034] Figure 3 shows a diagram showing an example of carrier aggregation when using LTE concomitantly in the licensed and unlicensed spectrum according to various modalities.

[0035] Figure 4 is a block diagram conceptually showing a base station/eNB design and a UE configured in accordance with an aspect of the present disclosure.

[0036] Figure 5 is a block diagram showing a transmitter that transmits an F-CUBs.

[0037] Figure 6 is a diagram showing a transmission flow that includes transmissions from F-CUBs.

[0038] Figures 7-12 are block diagrams showing exemplary blocks executed to implement various aspects of the present disclosure.

DETAILED DESCRIPTION

[0039] The detailed description presented below in connection with the attached drawings is intended to be a description of various configurations and is not intended to limit the scope of the disclosure. Instead, the detailed description includes specific details for the purpose of providing a complete understanding of the subject matter of the invention. It will be apparent to those skilled in the art that these specific details are not necessary and that, in some cases, well-known structures and components are shown in block diagram form for greater clarity of presentation.

[0040] Carriers have thus far looked to WiFi as the basic mechanism for utilizing unlicensed spectrum to alleviate ever-increasing levels of congestion in cellular networks. However, a new carrier type (NCT) based on LTE/LTE-A that includes unlicensed spectrum can be compatible with carrier type WiFi, making LTE/LTE-A with unlicensed spectrum an alternative to WiFi. LTE/LTE-A with unlicensed spectrum can leverage LTE concepts and can introduce some modifications to the physical layer (PHY) and media access control (MAC) aspects of the network or network devices to provide effective operation in the unlicensed spectrum and to satisfy regulatory requirements. Unlicensed spectrum can range from 600 megahertz (MHz) to 6 Gigaherz (GHz), for example. In some scenarios, LTE/LTE-A with unlicensed spectrum can perform significantly better than WiFi. For example, LTE/LTE-A with unlicensed spectrum deployment for a single carrier, or multiple carriers, compared to an all WiFi deployment, or when there are dense small cell deployments. LTE/LTE-A with unlicensed spectrum can significantly outperform WiFi. LTE/LTE-A with unlicensed spectrum can outperform WiFi in other scenarios, such as when LTE/LTE-A with unlicensed spectrum can outperform WiFi in other scenarios, such as when LTE/ LTE-A with unlicensed spectrum is mixed with WiFi (for a single or multiple operators).

[0041] For a single service provider (SP), an LTE/LTE-A network with unlicensed spectrum can be configured to be synchronous with an LTE network on licensed spectrum. However, LTE/LTE-A networks with unlicensed spectrum deployed on a given channel by multiple SPs can be configured to be synchronous across multiple SPs. One approach to incorporating both of the above features may involve utilizing a constant timing offset between LTE/LTE-A networks without unlicensed spectrum and LTE/LTE-A networks with unlicensed spectrum for a given SP. An LTE/LTE-A network with unlicensed spectrum can provide unicast or broadcast services according to the needs of the SP. Furthermore, an LTE/LTE-A network with unlicensed spectrum can operate in a launch mode in which LTE cells act as an anchor and provide relevant cellular information (e.g., radio frame timing, channel configuration common, system frame number or SFN, etc.) for LTE/LTE-A cells with unlicensed spectrum. In this mode there can be close interoperability between LTE/LTE-A without unlicensed spectrum and LTE/LTE-A with unlicensed spectrum. For example, the boot mode may support the supplemental downlink and carrier aggregation modes described above. The PHY-MAC layers of the LTE/LTE-A network with unlicensed spectrum can operate in an independent mode in which the LTE/LTE-A network with unlicensed spectrum operates independently of an LTE network without unlicensed spectrum. In this case, there may be loose interoperability between LTE without unlicensed spectrum and LTE/LTE-A with unlicensed spectrum based on aggregation at the RLC level with LTE/LTE-A co-located with/without unlicensed spectrum cells or multi-flow across multiple cells or base stations, for example.

[0042] The techniques described here are not limited to LTE and can also be used in various wireless communication systems, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and other systems. The terms “system” and “network” are often used interchangeably. A CDMA system can implement radio technology such as CDMA2000, Universal Terrestrial Radio Access (UTRA), etc. CDMA2000 covers the IS-2000, IS-95, and IS-856 standards. IS-2000 Versions 0 and A are commonly referred to as CDMA2000 1X, 1X, etc. IS-856 (TIA-856) is commonly referred to as CDMA2000 1xEV-DO, High Rate Packet Data (HRPD), etc. UTRA includes Broadband CDMA (WCDMA) and other CDMA variants. A TDMA system can implement a radio technology such as the Global System for Mobile Communications (GSM). An OFDMA system can implement radio technology such as Ultra Mobile Broadband (UMB), Evolved UTRA (E-UTRA), IEEE 802.11 (WiFi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM, etc. UTRA and E-UTRA are part of the Universal Mobile Telecommunications System (UMTS), LTE and LTE-Advanced (LTE-A) are new versions of UMTS that use E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A and GSM are described in documents from an organization called the “3rd Partnership Project.” Generation” (3GPP). CDMA2000 and UMB are described in documents from an organization called the “3rd Partnership Project.” Generation 2” (3GPP2). The techniques described here can be used in the systems and radio technologies mentioned above as well as in other systems and radio technologies. The following description, however, describes an LTE system for exemplification purposes, and LTE terminology is used in much of the following description, although the techniques are applicable beyond LTE applications.

[0043] Therefore, the following description presents examples that do not limit the scope, applicability or configuration presented in the claims. Changes can be made in the arrangement of the elements discussed without abandoning the spirit and scope of the revelation. Various embodiments may omit, replace, or add various procedures or components as appropriate. For example, the described methods may be performed in a different order than described, and several steps may be added, omitted, or combined. Furthermore, features described with respect to certain embodiments may be combined in other embodiments.

[0044] Referring first to Figure 1, a diagram shows an example of a wireless communications system or networks 100. The system 100 includes base stations (or cells) 105, communications apparatus 115, and a basic network 130. The base stations 105 may communicate with communications apparatus 115 under the control of a base station controller (not shown), which may be part of the core network 130 or the base stations 105 in various embodiments. The base stations 105 may communicate control information and/or user data with the network 130 via the backhaul channel 132. In embodiments, the base stations 105 may communicate, either directly or indirectly, with each other via of return transport links 134 which may be wired or wireless communication links. The system 100 can support operation on multiple carriers (waveform signals of different frequencies). Multi-carrier transmitters can transmit modulated signals simultaneously on multiple carriers. For example, each communication link 125 may be a multi-carrier signal modulated in accordance with the various radio technologies described above. Each modulated signal can be sent on a different carrier and can carry control information (such as reference signals, control channels, etc.), overhead information, data, etc.

[0045] Base stations 105 may communicate wirelessly with devices 115 via one or more base station antennas. Each of the base station 105 locations may provide communications coverage for a respective geographic coverage area 110. In some embodiments, the base station 105 may be referred to as a base transceiver station, radio base station, access point, radio transceiver. , basic service set (BSS), extended service set (ESS), NodeB, eNodeB (eNB), Native Node, Native eNode, or some other suitable terminology. The coverage area 110 for a base station can be divided into sectors that constitute only a part of the coverage area (not shown). The system 100 may include base stations 105 of different sizes (macro, micro, and/or pico-base stations, for example). There may be overlapping coverage areas for different technologies.

[0046] In some embodiments, system 100 may be an LTE/LTE-A network that supports one or more operating modes or deployment scenarios in unlicensed LTE/LTE-A spectrum. In other embodiments, system 100 may support wireless communications using an unlicensed spectrum and an access technology other than LTE/LTE-A with unlicensed spectrum, or a licensed spectrum and an access technology other than LTE/LTE-A. The terms Evolved NodeB (eNB) and user equipment (UE) may generally be used to describe base stations 105 and devices 115 respectively. System 100 may be a Heterogeneous LTE/LTE-A network with or without unlicensed spectrum in which different types of eNB provide coverage for different geographic regions. For example, each eNB 105 may provide communication coverage for a macrocell, a picocell, a femtocell, and/or other cell types. Small cells such as pico-cells, femto-cells and other cell types may include low-power nodes or LPNs. A macro-cell generally covers a relatively large geographic area (within a radius of several kilometers, for example) and can allow unrestricted access by UEs with service subscriptions from the network provider. A pico-cell would generally cover a relatively smaller geographic area and may allow unrestricted access by UEs with service subscriptions with the network provider. A femto-cell would also generally cover a relatively small geographic area, a residence, for example) and, in addition to unrestricted access, may also provide restricted access by UEs that have association with the femto-cell (UEs in a closed group of subscribers (UEs in a closed subscriber group). CSG), UEs for home users and similar, for example). An eNB for a macro-cell can be referred to as a macro-eNB. An eNB for a pico-cell can be referred to as a pico-eNB. Furthermore, an eNB for a femto-cell can be referred to as femto-eNB or Native eNB. An eNB can support one or multiple cells (two, three, four cells and the like, for example).

[0047] The basic network 130 can communicate with the eNBs 105 via a return transport channel 132 (such as, for example, S1, etc.) The eNBs 105 can also communicate with each other, via example, directly or indirectly, via return transport links 134 (such as, for example, X2, etc.) and/or via return transport links 132 (through the core network 130, for example). System 100 may support synchronous or asynchronous operation. For synchronous operation, eNBs can have similar frame timing and/or gate connection, and transmissions from different eNBs can be approximately aligned in time. For asynchronous operation, eNBs can have frame timing; connection via different gate, and transmissions from different eNBs may not be aligned in time. The techniques described here can be used in either synchronous or asynchronous operation.

[0048] The UEs 115 are dispersed throughout the system 100, and each UE may be stationary or mobile. A UE 115 may also be referred to by those skilled in the art as a mobile station, subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile apparatus, wireless apparatus, wireless communication apparatus, remote apparatus, station of mobile subscriber, access terminal, mobile terminal, wireless terminal, remote terminal, telephone handset, user agent, mobile client, client or some other suitable terminology. A UE 115 may be a cellular telephone, a personal digital assistant (PDA), a wireless modem, a wireless communication device, a handheld device, a tablet computer, a laptop computer, a cordless telephone, a station wireless local loop (WLL), or similar. A UE is capable of communicating with macro-eNBs, pico-eNBs, femto-eNBs, relays, and the like.

[0049] Communication links 125 shown in system 100 may include uplink (UL) transmissions from a mobile device 115 to a base station 105, and/or downlink (DL) transmissions from a base station 105 to a mobile device 115 Downlink transmissions can also be called forward link transmissions, while uplink transmissions can also be called reverse link transmissions. Downlink transmissions can be made using licensed spectrum (LTE/LTE-A licensed spectrum, for example), unlicensed spectrum (LTE/LTE-A unlicensed spectrum, for example), or both (LTE/LTE-A with/without unlicensed spectrum). Likewise, uplink transmissions can be made using licensed spectrum (LTE, for example), unlicensed spectrum (LTE/LTE-A with unlicensed spectrum, for example), or both (LTE/LTE-A with/without unlicensed spectrum).

[0050] In some embodiments of system 100, various deployment scenarios for LTE/LTE-A with unlicensed spectrum may be supported, including a supplemental download (SDL) mode, in which LTE downlink capacity in licensed spectrum may be offloaded to unlicensed spectrum, a carrier aggregation mode, in which both LTE/LTE-A downlink and uplink capacity can be offloaded from licensed spectrum to unlicensed spectrum, and an independent mode, in which which LTE/LTE-A downlink and uplink communications between a base station (eNBs, for example) and a UE can occur in an unlicensed spectrum. The base stations 105 as well as the UEs 115 may support one or more of these modes of operation or similar modes of operation. OFDM communication signals may be used in communication links 125 for LTE downlink transmissions in unlicensed spectrum, while SC-FDMA communication signals may be used in communication links 125 for LTE uplink transmissions in unlicensed spectrum. Additional details regarding the implementation of LTE/LTE-A with deployment scenarios or modes of operation on a system such as system 100, as well as other features and functions related to the operation of LTE/LTE-A with unlicensed spectrum, are shown below with reference to Figures 2A-12.

[0051] Referring next to Figure 2A, a diagram 200 shows examples of a supplementary downlink mode and a carrier aggregation mode for an LTE network that supports LTE/LTE-A with unlicensed spectrum. The diagram 200 may be an example of parts of the system 100 of Figure 1. Furthermore, the base station 105a may be an example of the base stations 105 of Figure 1, while the UEs 115a may be examples of the UEs 115 of Figure 1.

[0052] In the example of a supplemental downlink mode in diagram 200, the base station 105-a may transmit OFDMA communication signals to a UE 115-a using a downlink 205. The downlink 205 is associated with a frequency F1 in a spectrum unlicensed. The base station 105-a can transmit OFDMA communication signals to the same UE 115-a using a bidirectional link 210 and can receive SC-FDMA communication signals from that UE 115-a using the bidirectional link 210. The bidirectional link 210 is associated at an F4 frequency in a licensed spectrum. The downlink 205 in the unlicensed spectrum and the bidirectional link 210 in the licensed spectrum may operate concurrently. The downlink 205 may provide an offload of downlink capacity to the base station 105-a. In some embodiments, downlink 205 may be used for unicast services (addressed to one UE, for example), or for multicast services (addressed to multiple UEs, for example). This scenario can occur with any service provider (traditional mobile network operator or MNO, for example) that uses licensed spectrum and needs to alleviate some of the traffic and/or signaling congestion.

[0053] In an example of carrier aggregation mode in diagram 200, the base station 105-a may transmit OFDMA communication signals to a UE 115-a using a bidirectional link 215 and may receive SC-FDMA communication signals from the same UE 115-a using bidirectional link 215. Bidirectional link 215 is associated with frequency F1 in the unlicensed spectrum. The base station 105-a can also transmit OFDMA communication signals to the same UE 115-a using a bidirectional link 220 and can receive SC-FDMA communication signals from the same UE 115-a using the bidirectional link 220. The bidirectional link 220 is associated with an F2 frequency in a licensed spectrum. The bidirectional link 215 may provide an offload of downlink and uplink capacity to the base station 105-a. As a supplementary downlink described above, this scenario can occur with any service provider (MNO, for example) that uses licensed spectrum and needs to alleviate some of the traffic and/or signaling congestion.

[0054] In another example of the carrier aggregation mode in diagram 200, the base station 105-a may transmit OFDMA communication signals to a UE 115-a using a bidirectional link 225 and may receive SC-FDMA communication signals from the same UE 115-a using bidirectional link 225. Bidirectional link 225 is associated with an F3 frequency in an unlicensed spectrum. The base station 105-a can also transmit OFDMA communication signals to the same UE 115-a using a bidirectional link 230 and can receive SC-FDMA communication signals from the same UE 115-a using the bidirectional link 230. The bidirectional link 230 is associated with frequency F2 in the licensed spectrum. The bidirectional link 225 may provide an offload of downlink and uplink capacity to the base station 105-a. This example and those presented above are presented for illustrative purposes and there may be other similar operating modes or deployment scenarios that combine LTE/LTE-A with or without unlicensed spectrum for capacity offload.

[0055] As described above, the typical service provider that can benefit from the capacity offload offered by utilizing LTE/LTE-A with unlicensed spectrum is a traditional MNO with LTE spectrum. For these service providers, an operational configuration may include an initialized mode (supplementary downlink, carrier aggregation, for example) that utilizes an LTE primary component carrier (PCC) in licensed spectrum and the LTE secondary component carrier (SCC) in unlicensed spectrum. licensed.

[0056] In supplemental downlink mode, control for LTE/LTE-A with unlicensed spectrum may be carried via the LTE uplink (the uplink portion of the bidirectional link 210, for example). One of the reasons for providing downlink capacity offload is because the demand for data is significantly driven by downlink consumption. Furthermore, in this mode, there may not be a regulatory impact since the UE is not transmitting in the unlicensed spectrum. There is no need to implement listen-before-talk (LBT) or carrier sense multiple access (CSMA) requirements on the UE. However, LBT can be implemented at the base station (eNB, for example), using an evaluation mechanism for periodic channel release (every 10 milliseconds, for example)(CCA) and/or catch-and-release aligned with a radio frame boundary.

[0057] In carrier aggregation mode, data and control can be communicated on LTE (directional links 210, 220 and 230, for example, while data can be communicated on LTE/LTE-A with unlicensed spectrum (bidirectional links 215 and 225, for example). Carrier aggregation mechanisms supported when using LTE/LTE-A with unlicensed spectrum may fall under hybrid frequency division duplexing/time division duplexing (FDD/FD-TDD), aggregation or a TDD-TDD carrier aggregation with different symmetry across component carriers.

[0058] Figure 2B shows a diagram 200-a that shows an example of the standalone mode for LTE/LTE-A with unlicensed spectrum. Diagram 200-a may be an example of parts of system 100 of Figure 1. Furthermore, base station 105-b may be an example of base stations 105 of Figure 1 and base station 105-a of Figure 2A. While the UE 115-b may be an example of the UEs 115 of Figure 1 and the UEs 115-a of Figure 2A.

[0059] In the independent mode example in diagram 200-a, the base station 105-b may transmit OFDMA communication signals to the UE 115-b using a bidirectional link 240 and may receive SC-FDMA communication signals from the same UE 115 -b using bidirectional link 240. Bidirectional link 240 is associated with frequency F3 in the unlicensed spectrum described above with reference to Figure 2A. The independent mode can be used in non-traditional wireless access scenarios, such as stadium access (unicast, multicast, for example). A typical service provider for this mode of operation might be a stadium owner, cable company, event hosts, hotels, businesses and large corporations that do not have licensed spectrum. For these service providers, an operational configuration for standalone mode can utilize PCC in the unlicensed spectrum. Furthermore, LBT can be implemented at both the base station and the UE.

[0060] Referring next to Figure 3, a diagram 300 shows an example of carrier aggregation when using LTE concomitantly in the licensed and unlicensed spectrum, according to various embodiments. The carrier aggregation scheme in diagram 300 may correspond to the hybrid FDD-TDD carrier aggregation described above with reference to Figure 2A. This type of carrier aggregation can be used in at least parts of the system 100 of Figure 1. Furthermore, this type of carrier aggregation can be used in the base stations 105 and 105-a of Figure 1 and Figure 2A, respectively. , and/or in UEs 115 and 115-a of Figure 1 and Figure 2A respectively.

[0061] In this example, an FDD (FDD-LTE) can be performed in connection with LTE in the downlink. A first TDD (TDD1) can be performed in connection with LTE/LTE-A with unlicensed spectrum. A second TDD (TDD2) can be made in connection with LTE with licensed spectrum and another FDD (FDD-LTE) can be made in connection with LTE in the uplink with licensed spectrum. TDD1 results in a DL:UL ratio of 6:4, while the ratio for TDD2 is 7:3. On the time scale, the different DL:UL ratios are 3:1, 1:3, 2:2, 3:1, 2:2 and 3:1. This example is presented for illustration purposes and there may be other carrier aggregation schemes that combine their LTE/LTE-A operations with or without unlicensed spectrum.

[0062] Figure 4 shows a block diagram of a base station/eNB 105 design and a UE 115 that may be one of the base stations/eNBs and one of the UEs of Figure 1. The eNB 105 may be equipped with antennas 434a to 434t, and the UE 115 can be equipped with antennas 452a to 452r. In the eNB 105, a broadcast processor 420 may receive data from a data source 412 and control information from a controller/processor 440. The control information may be for the physical broadcast channel (PBCH), format indicator channel physical control (PCFICH), physical hybrid automatic repeat request indicator channel (PHICH), physical downlink control channel (PDCCH), etc. The data can be for the physical downlink shared channel (PDSCH), etc. The transmission processor 420 may process (encode and map into symbols, for example), the data and control information to obtain data symbols and control symbols, respectively. The transmission processor 420 may also generate reference symbols, such as for the primary synchronization signal (PSS), the secondary synchronization signal (SSS), and the cell-specific reference signal. A multi-input, multi-output (MIMO) transmission (TX) processor 430 may perform spatial processing (precoding, for example) on data symbols, control symbols, and/or reference symbols, if applicable, and can generate output symbol beams for modulators (MODs) 432a to 432t. Each modulator 432 may process a respective output symbol stream (such as for OFDM, etc.) to obtain an output sample stream. Each modulator 432 may also process (convert to analog, amplify, filter, and upconvert, for example) the output sample stream to obtain a downlink signal. Downlink signals from modulators 432a to 432t can be transmitted through antennas 434a to 434t, respectively.

[0063] In the UE 115, the antennas 452a to 432r can receive the downlink signals from the eNB 105 and can send received signals to the demodulators (DEMODs) 454a to 454r, respectively. Each demodulator 454 can condition (filter, amplify, downconvert and digitize, for example) a respective received signal in order to obtain input samples. Each demodulator 454 may also process the input samples (such as for OFDM, etc.) to obtain received symbols. A MIMO detector 456 can obtain symbols received from all demodulators 454a to 454r. Perform MIMO detection on received symbols, if applicable, and generate detected symbols. A receiving processor 458 may process (demodulate, deinterleave, and decode, for example) the detected symbols, send the decoded data to the UE 115 to a data store 460, and send decoded control information to a controller/processor 480.

[0064] In the uplink, in the UE 115, the transmission processor 464 may receive and process data (for the physical uplink shared channel (PUSCH), for example) from a data source 462 and control information (for the physical uplink control (PUCCH) for example) of the controller/processor 480. The transmission processor 464 may also generate reference symbols for a reference signal. The symbols from the transmission processor 464 may be pre-coded by a MIMO TX processor 466 if applicable, also processed by demodulators 454a to 454r (such as, for example, for SC-FDM, etc.), and transmitted to the eNB 105. In the eNB 105, the uplink signals from the UE 115 may be received by the antennas 434, processed by the modulators 432, detected by a MIMO detector 436, if applicable, and also processed by a receive processor 438 in order to obtain data and information decoded control information and sent by the UE 115. The processor 438 may send the decoded data to a data store 439 and the decoded control information to the controller/processor 440.

[0065] Controllers/processors 440 and 480 can direct operation in the eNB 105 and the UE 115 respectively. The controller/processor 440 and/or other processors and modules in the eNB 105 may execute or direct the execution of various processes for the techniques described herein. The controller/processor 480 and/or other processors and modules in the UE 115 may also execute or direct the execution of the functional blocks shown in Figures 7-12 and/or other processes for the techniques described herein. Memories 442 and 482 can store data and program codes for the eNB 105 and/or the UE 115, respectively. A programmer 444 can program UEs for data transmission in the downlink and/or uplink.

[0066] As previously noted, with increasing data traffic in cellular networks utilizing a licensed radio frequency band, offloading at least some data traffic to a contention-based radio frequency spectrum that includes unlicensed frequency bands may provide a cellular operator (a public land mobile network (PLMN) operator and/or a coordinated set of base stations that define a cellular network, such as an LTE/LTE-A network) opportunities for enhanced transmission transmission capacity of data. Before gaining access to, and communicating through, the contention-based frequency spectrum band, a transmitting equipment may, in some examples, perform an LBT procedure to gain access to the contention-based radio frequency band. As noted, such an LBT procedure may include performing a CCA procedure in order to determine whether a channel in the band of an unlicensed radio frequency spectrum is available. In additional examples, an extended CCA (ECCA) procedure may be performed that includes multiple CCA procedures. When it is determined that a channel is available, the transmitting equipment may communicate over a carrier that includes an available channel. The transmitting equipment can also broadcast CUBS in order to indicate the use of the available channel to other UEs and/or base stations.

[0067] ECCA procedures are not necessarily synchronous with the underlying communication timing. Therefore a transmitter may not determine a successful ECCA precisely at a subframe, partition, or symbol boundary. When a successful ECCA is detected in the middle of a specific subframe, partition, or symbol, the transmitter may immediately begin transmitting a channel reservation signal, such as a CUBS, in the middle of the subframe, partition, or symbol. in order to preserve the channel. This partial CUBS can be referred to as fractional CUBS (F-CUBS). However, when transmitting an F-CUBS, a transmitter uses the same signaling sequence for the F-CUBS as for the regular CUBS transmitted in the next subframe, partition, or symbol. Because of this signaling reuse, there may be a non-negligible probability that a receiver will detect the F-CUBS and decode it as a regular CUBS, which may cause undesirable behavior at the receiver. For example, the receiver incorrectly identifying the F-CUBS as CUBS would expect the subsequent subframe, partition, or symbol to contain data transmission. Furthermore, for a UE receiver, it may attempt to decode an enhanced frame formatting indicator on the subframe, partition or symbol and F-CUBS. The frame formatting indicator may be signaled on an enhanced frame formatting indicator channel (EFFICH) or may be signaled on any other downlink Layer 1 channel. The enhanced frame formatting indicator is a frame configuration indicator that includes identification of the uplink/downlink subframe configuration in the following frame. Therefore, a UE receiver may incorrectly determine the uplink/downlink configuration for the entire transmission frame.

[0068] Figure 5 is a block diagram showing a transmitter 500 that transmits an F-CUBS. Transmitter 500 participates in communications via transmission stream 50. Activity status graph 51 shows when transmitter 500 is on and off. During the ECCA process, the transmitter 500 is turned off. However, at time 501, the ECCA is detected as successful and transmitter 500 begins transmitting to F-CUBS 503. Time 501 falls within subframe 502 of transmission stream 50, which is in the middle of subframe 502. frame 502. Thus, subframe 502 includes a muted or override period 504, when transmitter 500 is off and performing ECCA, and an active period, when transmitter 500 is on and transmitting F-CUBS 503. For example , transmitter 500 may be transmitting F-CUBS 503 for the remaining 67 μs of subframe 502. Thus, transmitter 500 transmits F-CUBS 503 with 67 μs in subframe 503 and transmits a full 14-symbol CUBS in subframe 505. A receiver would have a very high probability of detecting CUBS in subframe 502 when the transmitter 500 is actually transmitting the F-CUBS 503. Depending on the time duration of the F-CUBS 503, a UE receiver may decode the indicator improved frame formatting correctly or incorrectly.

[0069] It should be noted that transmitter 500 may be a type of base station or access point that prepares for downlink data transmissions or may be a UE that prepares for uplink data transmissions. In such a contention-based system, the transmitting entity would first determine whether any specific contention-based carrier is free before reserving carrier aggregation for its own transmissions.

[0070] Figure 6 is a block diagram showing a stream of transmissions 600 that includes F-CUBS transmissions. Base station 60 and/or UE 61 participate in communications via transmission stream 600. In downlink transmissions, base station 60 performs an ECCA procedure and detects a successful ECCA at time 602 of subframe 9. During During the ECCA 601 nullification period, base station 60 transmitters would be turned off. Base station 60 will then begin transmitting F-CUBS at time 602 so as to reserve the channel up to the boundary of subframe 603 between subframe 9 and a subframe 0. In subframe 0, the base station 60 60 will begin broadcasting CUBS. In the example shown, base station 60 is transmitting a regular CUBS in subframe 0. However, the UE 61 may incorrectly determine that the F-CUBS transmitted between time 602 and the boundary of subframe 603 is a regular CUBS and , therefore, would expect an enhanced common reference signal (eCRS) and data to be transmitted in subframe 0. The false alarm on the eCRS transmission will request CQI reports from user 61 to base station 60. The false alarm on the PDCCH would also impact PDSCH detection and decoding performance in the UE 61. Furthermore, as previously mentioned, decoding errors in the enhanced frame formatting indicator will have an impact on both downlink and uplink performance. . For example, if the UE 61 believes that the subsequent subframe is an uplink subframe, when in fact it is scheduled as a downlink subframe, the uplink transmissions may cause interference with the scheduled downlink transmissions. or prevent base station 60 from having a successful CCA or ECCA for downlink transmissions. Downlink transmissions may cause interference to uplink transmissions in a similar manner when the UE 61 incorrectly decodes the EFFICH. Table 1 (Translation of Table 1: Missed Detection Prob; Geometry (Db); within table: No Cancellation; 10%, 20%, etc. Cancellation)

[0071] Table 1 represents a graph of incorrect detection of F-CUBS signals through different blanking periods. The override period (the 504 override period (Figure 5) and the ECCA override period (Figure 6, for example) is the part of the subframe in which the transmitter is turned off and executing the ECCA procedure. With the graph in Table 1, the non-trivial false alarm of misidentifying a CUBS from a detected F-CUBS occurs even with only 10% CUBS power (with 90% of the subframe in the blanking period). Since the CUBS or F-CUBS typically occupies one of N resource elements (REs) in a CUBS or F-CUBS transmission (N = 3, 4, 5, for example), the false alarm rate would not improve by appreciable way even if the F-CUBS moved cyclically in the time domain. For example, it moved cyclically up to half the number of samples (1024 + M, where M = 72, for example). Because of the occupancy of REs in the CUBS , the time domain in phase/quadrature (I/Q) samples with CUBS and F-CUBS transmissions would have repetition. Such repetition can cause non-negligible peak energy in a given timing window even with the use of a limited search. Thus, detection of false alarm CUBS can be observed even with a limited search window when a time-shifted CUBS is used for F-CUBS transmissions. Various aspects of the present disclosure relate to reducing or eliminating the likelihood of incorrect detection of CUBS and F-CUBS transmissions.

[0072] Figure 7 is a block diagram showing exemplary blocks executed to implement an aspect of the present disclosure. In block 700, a transmitter detects a successful ECCA check on a contention-based carrier before the boundary of the current subframe, partition, or symbol. As shown above, ECCA is detected as successful in the middle of the subframe in which the transmitter is turned off during the ECCA process. The transmitter can identify successful ECCA transmission and compare this timing with the timing of the current frame so as to detect successful ECCA before the sub-frame boundary.

[0073] In block 701, the transmitter transmits a fractional channel reservation signal, such as an F-CUBS, for the remainder of the current subframe, wherein the fractional channel reservation signal is generated using a first sequence . GUBS transmissions are generated using known CUBS sequences. The CUBS sequence may be a function of the cell ID, the public land mobile number (PLMN) ID, or both. In an example operation of block 701, a transmitter would generate the F-CUBS using a first sequence.

[0074] In block 702, the transmitter transmits a channel reservation signal that begins in the subsequent subframe, wherein the channel reservation signal is generated using a second sequence different from the first sequence. In such exemplary operation, the transmitter generates the regular CUBS transmission using a CUBS sequence different from the F-CUBS transmission. Thus, a receiver entity under the exemplary aspect is able to distinguish F-CUBS from CUBS, since each of the signals is generated using a different sequence.

[0075] In various aspects of the present disclosure, the second sequence may be a derivative version of the first sequence. Deriving the second sequence from the first reduces implementation complexity, since the transmitter can derive the second sequence from the first on the fly, rather than generating and storing another sequence. For example, F-CUBS may be a sequence that is derived as the reverse order of the CUBS sequence. Such a reverse order sequence can result in good cross-correlation with respect to standard CUBS transmission.

[0076] In another exemplary aspect, the F-CUBS may utilize a sequence that is derived as the inverted phase/quadrature (IQ) of the CUBS sequence, such that the F-CUBS takes quadrature components from the CUBS and uses them as phase components to F-CUBS at the same time taking the phase components from the CUBS and using them as quadrature components. In yet another exemplary aspect, F-CUBS can utilize a sequence that is derived as the product of the original CUBS sequence multiplied by another sequence, where the other sequence can be easily implemented. For example, the other sequence may be a sequence with a random phase or a deterministic sequence, such as “+ + - + + - -...” which can be easily generated at run time with limited complexity. In another example, with the deterministic sequence “+ + - + + - -...”, the transmitter would merely invert the signal of IQ samples every other sample.

[0077] Furthermore, the sequence used to generate F-CUBS may be completely different or orthogonal to the sequence used to generate standard CUBS. Aspects of the present disclosure are not limited to any specific relationship between the different sequences of F-CUBS and CUBS.

[0078] It should also be noted that, with respect to the aspect shown in Figure 7, complexity can be added as a consequence of the different sequences. For example, the transmitter will now switch from the idle state to the F-CUBS with the first sequence. For transmission of CUBS with a different sequence and then for data transmission.

[0079] Figure 8 is a block diagram showing exemplary blocks executed to implement a further aspect of the present disclosure. In block 800 a transmitter detects successful ECCA verification on a contention-based carrier before the boundary of the current subframe, partition or symbol. As shown above, ECCA is detected as successful in the middle of the subframe where the transmitter is off during the ECCA processor.

[0080] In block 801, the transmitter transmits a channel reservation signal on the carrier starting in the subsequent subframe. In an exemplary light, the transmitter does not transmit an F-CUBS at all. Instead, the transmitter remains idle from the time the successful ECCA was detected in the middle of the previous subframe, partition, or symbol and the beginning of the next subframe. At the beginning of the next subframe, the transmitter will transmit a regular channel reservation signal, such as a CUBS broadcast.

[0081] In further implementations of the exemplary aspect of Figure 8, the transmitter may perform a CCA check before transmitting the CUBS in the next subframe. Alternatively, the CCA check can only be performed when the idle period exceeds a specific predetermined threshold. In such aspects, the transmitter would compare the idle period with the limit and would only perform the CCA check if the idle time limit is exceeded.

[0082] Under the exemplary aspect shown in Figure 8, the transmitter may run the risk of losing the channel by not immediately starting to transmit the F-CUBS. However, the risk of the receiver incorrectly detecting a CUBS from a received F-CUBS is eliminated by not transmitting an F-CUBS.

[0083] Figure 9 is a block diagram showing exemplary blocks executed to implement an aspect of the present disclosure. In block 900, a UE receiver monitors a first subframe and a subsequent subframe for channel reservation signals. For example, a UE may monitor for CUBS transmissions in the last symbol (symbol 13, for example) of the last subframe (subframe 9, for example) of a frame and in the first symbol (symbol 0) of a first subframe (subframe 0, for example) of the subsequent frame.

[0084] In block 801, the UE determines that the first channel reservation signal detected in the first subframe is a fractional channel reservation subframe when the UE also detects the subsequent channel reservation signal in the subframe subsequent. Thus, for example, if the UE detects CUBS transmissions in both the last symbol of the subframe and the first symbol of the subsequent subframe, then it knows that the first CUBS transmission is actually an F-CUBS.

[0085] If the UE fails to detect a CUBS transmission in the subsequent sub-frame, the UE will instead determine that the first CUBS transmission detected in the first sub-frame is a standard CUBS transmission. Once the UE can determine which, if any, CUBS stream is F-CUBS and which CUBS stream is a standard CUBS, the UE can appropriately identify when to expect data signaling or additional signaling, such as EFFICH, eCRS, PDCCH and the like.

[0086] In further implementations of the aspect shown in Figure 9, the UE may be configured to perform parallel processing in the subsequent subframe for both CUBS and regular data transmissions. Thus, if the CUBS transmission detected in the first subframe turns out to be standard CUBS, then the signals received at the UE in the subsequent subframe would likely include regular data transmission. Therefore, the UE must process the signals in parallel or keep the signals of the subsequent subframe in a buffer for processing.

[0087] Figure 10 is a block diagram showing exemplary blocks executed to implement an aspect of the present disclosure. In block 100, a transmitter detects a successful ECCA check on a contention-based carrier before the boundary of the current subframe, partition, or symbol. As shown above, ECCA is detected as successful in the middle of the subframe, partition, or symbol, in which the transmitter is turned off during the ECCA process.

[0088] In block 1001, the transmitter transmits a fractional channel reservation signal, such as an F-CUBS, for the remainder of the current subframe. For example, the transmitter may transmit an F-CUBS for the remaining duration of the current subframe, between the time the successful ECCA is detected and the subframe boundary.

[0089] In block 1002, the transmitter begins transmitting data in the subsequent subframe. In the exemplary aspect shown in Figure 10, the transmitter avoids potential incorrect detection of CUBS from F-CUBS transmissions by skipping the CUBS transmission. The transmitter would reserve the contention-based carrier through the F-CUBS and begin regular data transmission in the next subframe.

[0090] In further implementations of the aspect shown in Figure 10, the transmitter would transmit any additional signaling that begins in the subsequent subframe after the F-CUBS. For example, the transmitter would transmit the EFFCICH in the subsequent subframe in addition to the data transmissions. Thus, the receiving UE would be able to appropriately detect the FFCICH so as to obtain the uplink/downlink subframe configuration. The UE may have a higher probability of losing F-CUBS transmission compared to CUBS transmission since F-CUBS transmission will not be across the entire subframe. However, the probability may not considerably affect the performance of the UE.

[0091] Figure 11 is a block diagram showing exemplary blocks executed to implement an aspect of the present disclosure. In block 1100, a transmitter detects a successful ECCA check on a contention-based carrier before the boundary of the current subframe, partition, or symbol. As shown above, ECCA is detected as successful in the middle of the subframe in which the transmitter is turned off during the ECCA process.

[0092] In block 1100, the transmitter transmits a fractional channel reservation signal, such as an F-CUBS, for the remainder of the current subframe. For example, the transmitter may transmit an F-CUBS for the remaining duration of the current subframe, between the time the successful ECCA is detected and the subframe boundary.

[0093] In block 1102, the transmitter transmits the channel reservation signal that begins in the subsequent subframe. For example, the transmitter may begin transmitting regular CUBS at the beginning of the next subframe.

[0094] In block 1103, the transmitter also transmits a frame formatting indicator along with the channel reservation signal in the subsequent subframe. In addition to transmitting CUBS in the subsequent subframe, for example, the transmitter will also transmit a frame formatting indicator, such as EFFICH. In additional implementations, the transmitter may also transmit eCRS in the subsequent subframe if the subsequent subframe is programmed for eCRS transmission.

[0095] Figure 12 is a block diagram showing exemplary blocks executed to implement an aspect of the present disclosure. In block 1200, a transmitter detects a successful ECCA check on a contention-based carrier before the boundary of the current subframe, partition, or symbol. As shown above, ECCA is detected as successful in the middle of the subframe in which the transmitter is turned off during the ECCA process.

[0096] In block 1201, the transmitter transmits a fractional channel reservation signal, such as an F-CUBS, for the remainder of the current subframe. For example, the transmitter may transmit an F-CUBS for the remaining duration of the current subframe, between the time the successful ECCA is detected and the subframe boundary.

[0097] In block 1202, the transmitter discards any CSI reports received from UEs by the transmitter in the subsequent subframe. In order to solve the problem of unreliable CSI feedback with incorrect detection of CUBS from F-CUBS transmissions, the exemplary aspect of Figure 12 causes the transmitter to simply disregard CSI feedback that may be unreliable. In additional implementations, the transmitter may disregard all CSI feedback received from UEs in the entire transmission frame after F-CUBS transmissions. In some instances, when the disregarded CSI report is for classification indication (RI) where subsequent CSI reports are for PMI and CQI, which are based on the disregarded RI, a transmitter may disregard the RI and subsequent CQI/PMI until that the next valid RI is reported.

[0098] It should be noted that the transmitters referred to in Figures 7, 8 and 10 may refer to transmitters that are either part of a base station or other access point preparing for downlink data transmissions or to UEs that prepare for uplink data transmissions. Network entities that transmit data over contention-based frequency spectrum would perform LBT procedures that may include CCA, ECCA, and the like, which may benefit from aspects of the present disclosure to reduce or eliminate incorrect detection of CUBS from F transmissions. -CUBS.

[0099] It should also be noted that transmitters forming any implementation of the aspects shown in Figures 7-12 may be a part of base stations and/or UEs as appropriate, such as the base stations 105 and UEs 115 of Figures 1 , 2, 4 and the base station 60 and/or UE 61 of Figure 6. Each of the described blocks, functions and resources can be implemented using the described structure for such base stations and UEs.

[0100] Those skilled in the art would understand that information and signals can be represented using any of a number of different technologies and techniques. For example, the data, instructions, commands, information signals, bits, symbols and chips referred to throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles or any combination thereof.

[0101] The functional blocks and modules of Figures 7-12 may comprise processors, electronic devices, hardware devices, electronic components, logic circuits, memories, software codes, firmware code, etc., or any combination thereof.

[0102] Those skilled in the art would also understand that the various blocks, modules, circuits and steps of illustrative logical algorithms described in connection with the present disclosure can be implemented as electronic hardware, computer software or in combinations of both. To clearly illustrate this interchangeability of hardware and software, several illustrative components, blocks, modules, circuits and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends on the specific application and the design constraints imposed on the system as a whole. Those skilled in the art may implement the described functionality in varying ways for each specific adaptation, but such implementation decisions should not be interpreted as causing a departure from the scope of the present disclosure. Those skilled in the art will also readily recognize that the order or combination of components, methods or interactions that are described herein are merely examples and that the components, methods or interactions of the various aspects of the present disclosure may be combined or carried out in ways other than those described and shown here.

[0103] The various illustrative logic blocks, modules and circuits described in connection with the present disclosure can be implemented or executed with a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC) , a field programmable gate array (FPGA) or other programmable logic device (PLD), discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but alternatively, the processor may be any conventional processor, controller, micro-controller or state machine. A processor may also be implemented as a combination of computing devices, such as, for example, a combination of DSP and microprocessor, a series of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other configuration as such.

[0104] The method or algorithm steps described in connection with the present disclosure may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. A software module may reside in RAM memory, ROM memory, flash memory, EPROM memory, EEPROM memory, registers, hard disk, removable disk, CD-ROM or any other form of storage medium known in the art. A storage medium may be coupled to a processor so that the processor can read information from, and write information to, the storage medium. Alternatively, the storage medium may be integral with the processor. The processor and storage medium can reside in an ASIC. The ASIC may reside on a user terminal. Alternatively, the processor and storage medium may reside as discrete components in a user terminal.

[0105] In one or more exemplary drawings, the described functions may be implemented in hardware, software, firmware or any combination thereof. If implemented in software, functions can be stored or transmitted as one or more instructions or code on a computer-readable medium. Computer-readable media include both computer storage media and communication media that include any medium that facilitates the transfer of a computer program from one place to another. A storage medium can be any available medium that can be accessed by a general purpose computer or special purpose processor. By way of example, and not limitation, such computer-readable media may comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other A medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a general purpose computer or special purpose processor or by a general purpose processor or computer processor. special purpose. Furthermore, a connection is appropriately called a computer-readable medium. For example, if software is transmitted from a website, server, or other remote source using coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), then the coaxial cable , fiber optic cable, twisted pair, DSL are included in the definition of medium. Disc, as used herein, includes compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), flexible disc, and Blu-ray disc, where discs usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above elements must also be included within the scope of computer-readable media.

[0106] As used herein, including in the claims, the term “and/or”, when used in a list of two or more items, means that any one of the enumerated items can be used by itself or any combination of two or more of the items listed can be used. For example, if a composition is described as containing components A, B and/or C, the composition may contain A alone; B alone; C alone; A and B in combination; A and C in combination; B and C in combination; or A, B and C in combination. Furthermore, as used herein, including in the claims “or”, as used in a list of items (a list of items preceded by a phrase such as “at least one of” or “one or more of”, for example) indicates a disjunctive list, so that, for example, a list of “at least one of A, B, or C” means A or B or C or AB or AC or BC or ABC (i.e., A and B and C) and any combination of them.

[0107] The foregoing description of the disclosure is presented to enable any person skilled in the art to manufacture or use the disclosure. Several modifications to the disclosure will be evident to those skilled in the art, and the generic principles defined herein can be applied to other variations without abandoning the spirit or scope of the disclosure. Accordingly, the disclosure is not intended to be limited to the examples and drawings described herein, but is to be given the broadest scope compatible with the novel principles and features disclosed herein.

Claims (5)

1. Wireless communication method, comprising: detecting (700), by a transmitter (500), a successful evaluation check for extended channel release, ECCA, on at least one carrier using a contention-based radio frequency spectrum , in which the successful ECCA check occurs before a boundary of one of: a subframe (502), partition or symbol of one of: a current subframe (502), a current partition or a current symbol; characterized by the fact that the method further comprises: remaining idle, by the transmitter (500), from the moment the successful ECCA was detected at the beginning of the next sub-frame; transmit (702), by the transmitter (500), a channel reservation signal that begins in a subsequent subframe (505) after the current subframe (502) on the at least one carrier. 2. Method, according to claim 1, characterized by the fact that it further comprises: performing, by the transmitter (500), a channel release evaluation check, CCA, before transmitting the channel reservation signal in the sub- subsequent frame; detecting, by the transmitter (500), the results of the CCA check, wherein transmission occurs in response to a successful CCA check. 3. Method according to claim 2, characterized by the fact that it further comprises: determining, by the transmitter (500), an idle time between the successful ECCA check and the boundary of the sub-frame, in which, the execution The CCA check occurs in response to the idle time exceeding a predetermined threshold. 4. Equipment configured for wireless communication, which comprises: at least one processor; and a memory coupled to the at least one processor, wherein the at least one processor is configured to: detect, by a transmitter (500), a successful extended channel release evaluation check, ECCA, on at least one carrier using a contention-based radio frequency spectrum in which the successful ECCA check occurs before a boundary of one of: a current subframe (502), a current partition, or a current symbol; characterized by the fact that the at least one processor is configured to: control the transmitter (500) to remain idle from the time the successful ECCA was detected until the beginning of the next sub-frame; and transmitting, by the transmitter (500), a channel reservation signal that begins in a subsequent subframe (505) after the current subframe (502) on the at least one carrier. 5. Computer-readable memory, characterized by the fact that it has instructions stored therein that, when executed, cause the computer to perform the method as defined in any one of claims 1 to 3.