System and method for enhancing coverage mode UE to handle uplink transmission conflicts

Abstract

The present disclosure relates to systems and methods for handling uplink transmission conflicts for enhanced coverage mode UEs. The present disclosure generally describes an eNode (eNB), a user equipment (UE), and a method for operating in an enhanced coverage (EC) mode. The UE may determine whether physical uplink control channel (PUCCH) signals and uplink signals assigned to different resources overlap in a particular subframe. The uplink signal may include another PUCCH signal or a physical uplink shared channel (PUSCH) signal. The PUCCH signal may include a scheduling request or an acknowledgement response / retransmission request. The UE may select one of the overlapping signals and transmit the selected signal on the resources assigned to the other signal rather than on the resources assigned to the one overlapping signal among the overlapping signals. The other signal may or may not be transmitted, depending on whether it is a PUCCH or a PUSCH signal.

Description

[0001] This application is a divisional application of the patent application for invention with the application date of August 25, 2015, application number 201580045440.1, and invention title "System and Method for Handling Uplink Transmission Collisions for Enhanced Coverage Mode UEs".

[0002] Priority Claims

[0003] This application claims the benefit of priority of U.S. Patent Application Serial No. 14 / 718,975, filed on May 21, 2015, which claims the benefit of priority of U.S. Patent Application Serial No. 62 / 055,596, filed on September 25, 2014, and titled "SYSTEM AND METHOD ASSOCIATED WITH HANDLING UPLINK TRANSMISSION COLLISION FOR MTC UES IN ENHANCED COVERAGE MODE", each of these applications being incorporated herein by reference in its entirety. Technical Field

[0004] Embodiments pertain to wireless communication. Some embodiments relate to cellular communication networks, which include Third Generation Partnership Project Long Term Evolution (3GPP LTE) networks and LTE Advanced (LTE-A) networks, as well as Fourth Generation (4G) networks and Fifth Generation (5G) networks. Some embodiments relate to enhanced coverage communication. Background Art

[0005] With the increase in the number of different types of devices communicating via a network to servers and other computing devices, the use of Third Generation Long Term Evolution (3GPP LTE) has increased. Specifically, typical User Equipment (UE) such as cellular phones and Machine-Type Communication (MTC) UEs currently use 3GPP LTE systems. Due to the low energy consumption involved in such communications, MTC UEs pose specific challenges. Specifically, MTC UEs are computationally less capable and have lower power for communication, and many are configured to remain at a single location essentially indefinitely. Examples of such MTC UEs include sensors (e.g., sensing environmental conditions) or microcontrollers in appliances or vending machines. In some environments, MTC UEs may be located in areas with little or no coverage, such as inside buildings, or in isolated geographical areas. Unfortunately, in many cases, MTC UEs do not have sufficient power to communicate with the nearest serving base station (enhanced Node B (eNB)) with which they communicate. Similar problems may exist for non-stationary wireless UEs such as mobile phones that are configured in network areas with poor coverage, i.e., areas where the link budget is several dB below the normal network value.

[0006] In cases where the UE is in such an area, the transmission power may not be increased by the UE or the eNB. To achieve coverage extension and gain additional dB in the link budget, the signal may be repeatedly transmitted from the transmitting device (either the UE or the eNB) across multiple subframes and physical channels over an extended period to accumulate energy at the receiving device (the other of the UE or the eNB). However, when data is repeatedly transmitted in this way, conflicts may occur between different channels. It is desirable to design a transmission that minimizes or completely avoids such conflicts. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] In the drawings (which are not necessarily drawn to scale), like numerals may describe similar components in different views. Like numerals with different letter suffixes may represent different instances of similar components. The drawings generally illustrate, by way of example and not limitation, the various embodiments discussed in this document.

[0008] Figure 1 is a functional diagram of a 3GPP network according to some embodiments.

[0009] Figure 2 is a block diagram of a 3GPP device according to some embodiments.

[0010] Figures 3A to 3D Illustrates an uplink subframe according to some embodiments.

[0011] Figures 4A to 4D Illustrates an uplink subframe according to some embodiments.

[0012] Figure 5 Illustrates a flowchart of a method for uplink conflict handling for enhanced coverage mode UEs according to some embodiments. DETAILED DESCRIPTION

[0013] The following description and drawings sufficiently illustrate specific embodiments to enable those skilled in the art to practice them. Other embodiments may incorporate structural, logical, electrical processes and other variations. Portions and features of some embodiments may be included in portions and features of other embodiments, or may replace portions and features of other embodiments. The embodiments set forth in the claims cover all available equivalent forms of those claims.

[0014] Figure 1 is a functional diagram of a 3GPP network according to some embodiments. The network may include a radio access network (RAN) (e.g., as shown, an E-UTRAN or evolved universal terrestrial radio access network) 100 and a core network 120 (e.g., shown as an evolved packet core (EPC)) coupled together via an S1 interface 115. For convenience and brevity, only a portion of the core network 120 and a portion of the RAN 100 are shown.

[0015] The core network 120 includes a Mobility Management Entity (MME) 122, a Serving Gateway (Serving GW) 124, and a Packet Data Network Gateway (PDN GW) 126. The RAN 100 includes an evolved Node B (eNB) 104 (which may operate as a base station) for communicating with the UE 102. The eNB 104 may include a macro eNB and a low power (LP) eNB.

[0016] The MME is functionally similar to the control plane of a legacy Serving GPRS Support Node (SGSN). The MME manages aspects of mobility in the access, such as gateway selection and tracking area list management. The Serving GW 124 terminates the interface towards the RAN 100 and routes traffic packets (such as data packets or voice packets) sent between the RAN 100 and the core network 120. Additionally, it can be a local mobility anchor point for inter-eNB handovers and can provide an anchor for inter-3GPP mobility. Other responsibilities may include lawful interception, charging, and some policy enforcement. The Serving GW 124 and the MME 122 can be implemented in one physical node or in separate physical nodes. The PDN GW 126 terminates the SGi interface towards the Packet Data Network (PDN). The PDN GW 126 routes traffic packets sent between the EPC 120 and the external PDN and can be a key node for policy enforcement and charging data collection. It can also provide an anchor point for mobility in the absence of LTE access. The external PDN can be any kind of IP network, as well as the IP Multimedia Subsystem (IMS) domain. The PDN GW 126 and the Serving GW 124 can be implemented in one physical node or in separate physical nodes.

[0017] The eNB 104 (macro and micro) terminates the air interface protocol and can be the first point of contact for the UE 102. The eNB 104 can communicate with both the UE 102 in normal coverage mode and the UE 104 in one or more enhanced coverage modes. In some embodiments, the eNB 104 can perform various logical functions for the RAN 100, including but not limited to RNC (Radio Network Controller functions) such as radio bearer management, uplink and downlink dynamic radio resource management and traffic packet scheduling, and mobility management. According to an embodiment, the UE 102 can be configured to communicate with the eNB 104 via a multi-carrier communication channel according to OFDMA communication technology to communicate OFDM communication signals. The OFDM signals can include a plurality of orthogonal subcarriers. Other technologies such as Non-Orthogonal Multiple Access (NOMA), Code Division Multiple Access (CDMA), and Orthogonal Frequency Division Multiple Access (OFDMA) can also be used.

[0018] The S1 interface 115 is the interface that separates the RAN 100 from the EPC 120. It is divided into two parts: S1-U that carries traffic packets between the eNB 104 and the Serving GW 124, and S1-MME, which is the signaling interface between the eNB 104 and the MME 122.

[0019] In the case of a cellular network, LP cells are typically used to extend coverage to indoor areas where outdoor signals do not reach well, or to add network capacity in areas with very dense phone usage such as train stations. As used herein, the term low-power (LP) eNB refers to any suitable relatively low-power eNB used to implement a narrower cell (narrower than a macro cell) such as a femto cell, a pico cell, or a micro cell. Femto eNBs are typically provided by a mobile network operator to its residential or enterprise customers. A femto cell is typically the size of a residential gateway or smaller and is typically connected to the user's broadband line. Once plugged in, the femto cell connects to the mobile network operator's mobile network and provides additional coverage within a range typically of 30 meters to 50 meters for a residential femto cell. Thus, an LP eNB can be a femto cell eNB as it is coupled via the PDN GW 126. Similarly, a pico cell is a wireless communication system that typically covers a small area such as inside a building (office, mall, train station, etc.) or inside a recent aircraft. A pico cell eNB is typically connected to another eNB such as a macro eNB via an X2 link through its base station controller (BSC). Thus, an LP eNB can be implemented with a pico cell eNB as it is coupled to the macro eNB via the X2 interface. A pico cell eNB or other LP eNB can incorporate some or all of the functionality of a macro eNB. In some cases, this can be referred to as an access point base station or an enterprise femto cell.

[0020] Communication via the LTE network is divided into 10 ms frames, each of which may contain ten 1 ms subframes. Each subframe in turn may contain two time slots of 0.5 ms. Each subframe can be used for uplink (UL) communication from the UE to the eNB or downlink (DL) communication from the eNB to the UE. The eNB can schedule uplink and downlink transmissions via various frequency bands. The allocation of resources in a subframe for one frequency band can be different from that for another frequency band. Each time slot of a subframe may contain 6 - 7 symbols. A subframe may contain 12 subcarriers. The downlink resource grid can be used for downlink transmission from the eNB to the UE, while the uplink resource grid can be used for uplink transmission from the UE to the eNB or from the UE to another UE. The resource grid can be a time - frequency grid, which is the physical resource in each time slot. The smallest time - frequency unit in the resource grid can be represented as a resource element (RE). Each column and each row of the resource grid can correspond to an OFDM symbol and an OFDM subcarrier respectively. The resource grid may contain resource blocks (RBs) that describe the mapping of physical channels to resource elements and physical RBs (PRBs). A PRB can be the smallest unit of resources that can be allocated to a UE. A resource block can be 180 kHz wide in frequency and 1 time slot long in time. In frequency, a resource block can be 12 x 15 kHz subcarriers wide or 24 x 7.5 kHz subcarriers wide. For most channels and signals, 12 subcarriers can be used per resource block, depending on the system bandwidth. The duration of the resource grid in the time domain can correspond to one subframe or two resource blocks. Each resource grid may include 12 (subcarriers) * 14 (symbols) = 168 resource elements.

[0021] Figure 2 is a functional diagram of a 3GPP device according to some embodiments. The device can be, for example, a UE or an eNB. In some embodiments, the eNB can be a stationary non - mobile device. The 3GPP device 200 may include physical layer circuitry 200 for transmitting and receiving signals using one or more antennas 201. The 3GPP device 200 may also include media access control layer (MAC) circuitry 204 for controlling access to the wireless medium. The 3GPP device 200 may further include processing circuitry 206 and memory 208 configured to perform the operations described herein.

[0022] In some embodiments, the mobile device or other devices described herein may be a portable wireless communication device, such as a personal digital assistant (PDA), a laptop or portable computer with wireless communication capabilities, a network tablet computer, a wireless telephone, a smart phone, a wireless headset, a pager, a real-time messaging device, a digital camera, an access point, a television, a medical device (e.g., a heart rate monitor, a blood pressure monitor, etc.), or part of other devices that can wirelessly receive and / or transmit information. In some embodiments, the mobile device or other device may be a UE 102 or an eNB 104 configured to operate according to 3GPP standards. In some embodiments, the mobile device or other device may be configured to operate according to other protocols or standards, including IEEE 802.11 or other IEEE standards. In some embodiments, the mobile device or other device may include one or more of a keyboard, a display, a non-volatile memory port, multiple antennas, a graphics processor, an application processor, a speaker, and other mobile device elements. The display may be an LCD screen including a touch screen.

[0023] Antenna 201 may include one or more directional or omnidirectional antennas, including, for example, dipole antennas, monopole antennas, patch antennas, loop antennas, microstrip antennas, or other types of antennas suitable for transmitting RF signals. In some multiple-input multiple-output (MIMO) embodiments, antennas 201 may be effectively separated to take advantage of spatial diversity and the different signal characteristics that may result.

[0024] Although the 3GPP device 200 is illustrated as having several discrete functional elements, one or more of the functional elements may be combined and may be implemented by a combination of software-configured elements, such as processing elements including a digital signal processor (DSP), and / or other hardware elements. For example, some elements may include one or more microprocessors, DSPs, field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), radio frequency integrated circuits (RFICs), and combinations of various hardware and logic circuitry for performing at least the functions described herein. In some embodiments, the functional elements may refer to one or more processing operations on one or more processing elements.

[0025] Embodiments may be implemented in one or a combination of hardware, firmware, and software. Embodiments may also be implemented as instructions stored on a computer-readable storage device, which may be read and executed by at least one processor to perform the operations described herein. A computer-readable storage device may include any non-transitory mechanism for storing information in a form readable by a machine, such as a computer. For example, a computer-readable storage device may include read-only memory (ROM), random access memory (RAM), magnetic disk storage media, optical storage media, flash memory devices, and other storage devices and media. Some embodiments may include one or more processors and may be configured with instructions stored on a computer-readable storage device.

[0026] The term "machine-readable medium" may include a single medium or multiple media (e.g., a centralized or distributed database, and / or associated caches and servers) configured to store one or more instructions. The term "machine-readable medium" may include any medium that is capable of storing, encoding, and / or carrying instructions for execution by a 3GPP device 200 and that causes the 3GPP device 200 to perform any one or more of the techniques of the present disclosure, or any medium that is capable of storing, encoding, or carrying a data structure used by or associated with such instructions. The term "transmission medium" will be used to include any intangible medium that is capable of storing, encoding, and / or carrying instructions for execution and includes digital or analog communication signals, or other intangible media that facilitate the communication of such software.

[0027] As indicated above, different types of UEs may use an enhanced coverage mode, in which information is repeatedly transmitted to allow the signal to be successfully decoded at the receiver. The UEs may include normal UEs (e.g., smart phones, etc.), machine-to-machine (M2M) UEs, or stationary wireless UEs using MTC (i.e., UEs that remain indefinitely in a single location). At least some of the UEs or serving eNBs cannot increase the transmission power in the enhanced coverage area because the UEs are inherently power-limited or limited by the eNB, for example, to reduce interference. In this case, when located in a position where the link budget to the nearest serving base station is worse than the normal link budget value in the network and additional link budget is to be obtained without increasing the transmission power, the UE may enter the enhanced coverage mode.

[0028] To increase signal power at the receiver without increasing the transmission power, the same packet data can be repeatedly transmitted by the transmitter. The transmitter can be either a UE (for uplink communication) or an eNB (for downlink communication), and the receiver can be the other of a UE (for downlink communication) or an eNB (for uplink communication). The UE can determine whether it desires an additional link budget and how much additional link budget it desires. In some embodiments, the additional link budget can include multiple discrete levels, such as up to approximately 5 dB, up to approximately 10 dB, up to approximately 15 dB, and up to approximately 20 dB. In response to determining how much additional link budget is desired, the UE can implement different enhanced coverage modes. In some embodiments, different enhanced coverage modes can be available, depending on the desired amount of additional link budget.

[0029] Typically, the UE can communicate via an operating bandwidth of 20 MHz. However, to reduce cost and power consumption, for both control and data channels, the operating bandwidth of the MTC UE can be reduced to, for example, 1.4 MHz. This can allow for an MTC resource region of limited resources (e.g., in frequency) for communication between the MTC UE and the eNB.

[0030] Independent of the operating bandwidth, there can be several different physical channels that use resource blocks for transmission. These physical channels can include the Physical Downlink Control Channel (PDCCH) and Physical Downlink Shared Channel (PDSCH) in downlink transmission, and the Physical Uplink Control Channel (PUCCH) and Physical Uplink Shared Channel (PUSCH) in uplink transmission. Each subframe can be divided into PDCCH and PDSCH or PUCCH and PUSCH. The PDCCH typically occupies the first two symbols of each subframe and carries information related to the transport format and resource allocation involving the PDCCH (including other information), as well as Hybrid Automatic Repeat reQuest (H-ARQ) information related to the uplink or downlink shared channel. The PDSCH can carry user data and higher layer signaling to the UE or eNB and occupies the remaining part of the subframe. The PUSCH can be shared by the UE to transmit data to the network. Scheduling is controlled by the eNB. Generally, downlink scheduling (allocating control and shared channel resource blocks to UEs within the cell) can be performed at the eNB based on channel quality information provided from the UE to the eNB, and then the downlink resource allocation information can be sent to each UE on the PDCCH for the UE (allocated to). The PDCCH can contain Downlink Control Information (DCI) in one of several different formats that tells the UE how to find and decode the data, which is transmitted from the resource grid on the PDSCH in the same subframe. The DCI format can provide details such as the number of resource blocks, resource allocation type, modulation scheme, transport block, redundancy version, coding rate, etc. Each DCI format can have a Cyclic Redundancy Check (CRC) and is scrambled with a Radio Network Temporary Identifier (RNTI), which identifies the target UE intended for the PDSCH. Using the UE-specific RNTI can limit the decoding of the DCI format (and thus the corresponding PDSCH) to the intended UE.

[0031] The PUCCH can carry information including Uplink Control Information (UCI), similar to the DCI of the PDCCH. The PUCCH can be mapped to a control channel resource defined by a code and two resource blocks, which are contiguous in time and potentially jump at the boundary between adjacent time slots. The PUCCH can take several different formats, where the UCI contains format-dependent information. Specifically, the PUCCH can contain a Scheduling Request (SR), an Acknowledgment Response / Retransmission Request (ACK / NACK), or a Channel Quality Indicator (CQI) / Channel State Information (CSI). The CQI / CSI can indicate the current channel condition and, if MIMO transmission is used by the UE, can include MIMO-related feedback.

[0032] To prevent the transport block from being lost, a Hybrid Automatic Repeat reQuest (HARQ) scheme can be used. When the eNB transmits PDSCH data to the UE in a downlink transmission, the data packet can be sent in the PDCCH together with an indicator in the same subframe, which notifies the UE of the scheduling of the PDSCH, including the transmission time and other characteristics of the transmitted data. For each PDSCH codeword received by the UE, the UE can respond with an ACK when the codeword is successfully decoded, or with a NACK when the codeword is not successfully decoded. The eNB can expect an ACK / NACK from a predetermined number of subframes of the subframe in which the PDSCH data is sent. Upon receiving a NACK from the UE, the eNB can retransmit the transport block or skip the retransmission. The ACK / NACK can be transmitted by the UE 4 subframes after receiving the signal from the eNB. Depending on the current number of codewords, the HARQ-ACK can contain 1 or 2 information bits (Formats 1a and 1b respectively). The HARQ-ACK bits can then be processed according to the PUCCH.

[0033] A scheduling request can allow the UE to request resources for transmission on the PUSCH. In some embodiments, no information bits are used to request resources for transmission on the PUSCH. However, the eNB can know the timing at which a scheduling request is expected from each UE within the cell. Thus, if PUCCH energy is detected, the eNB can identify it as a scheduling request from the corresponding UE. PUCCH Formats 1, 1a, and 1b can use four SC-FDMA symbols per time slot and can use no modulation scheme, Binary Phase Shift Keying (BPSK), and Quadrature Phase Shift Keying (QPSK). If the normal cyclic prefix is used, the remaining 3 symbols can be used for the PUCCH Demodulation Reference Signal (DM-RS). If the Sounding Reference Signal (SRS) overlaps with the PUCCH signal, only three symbols in the second time slot of the subframe can be used as PUCCH symbols. The DM-RS symbols can be used by the eNB to perform channel estimation and allow coherent demodulation of the received signal. The DM-RS symbols can be substantially pilot symbols in LTE for channel estimation for demodulation of the data symbols of the subframe.

[0034] The 3GPP specifications in TS 36.211 indicate that the UE cannot transmit uplink contention control or data signals within a subframe. The 3GPP specifications also support dedicated scheduling requests. That is, each UE in the cell can be assigned a specific resource index mapping, which provides resources that can be used every nth frame to transmit scheduling requests and other control or data signals. In such embodiments, since the eNB can schedule the UE individually, the possibility of contention between uplink transmissions in the normal mode can be minimized.

[0035] However, a UE in enhanced coverage mode may transmit uplink control or data signals in consecutive subframes to enable signal detection by the eNB. Although this may not cause problems of conflict between UEs, conflict may occur for a specific UE in enhanced coverage mode. Specifically, due to repetition, PUCCH (control) signals assigned to a set of physical resource blocks may overlap in time with another PUCCH signal or a PUSCH signal assigned to a different set of physical resource blocks. For example, scheduling request repetition may overlap with ACK / NACK repetition in the same subframe, and PUSCH repetition with data transmission or CSI reporting may overlap with ACK / NACK repetition in the same subframe. In this case, a set of predefined relationships may be defined to handle the overlap between repetitions such that once the overlap is determined, the enhanced coverage mode UE can select only one of the overlapping signals for transmission. The selected signal is not transmitted on the set of physical resource blocks associated with the selected signal, but on the set of physical resource blocks associated with other signals. This enables the UE to maintain the low CM single-carrier nature of the uplink transmission.

[0036] Figures 3A to 3D FIG. illustrates an uplink subframe according to some embodiments. Figures 3A to 3D Shows overlapping uplink transmissions under an enhanced mode UE such as an MTC UE as Figure 1 or Figure 2 shown. As shown, there are three sets of UL subframes A, B, C, where only one set of subframes contains an overlap between different uplink signals. Figures 3A to 3D Variously includes a start subframe SF for a scheduling request SR , HARQ ACK / NACK SF AN , and a repetition level RL SR and HARQ ACK / NACK repetition RL AN . In some embodiments, the repetition level (number of repetitions) may be the same between different signals and / or different UEs. In some embodiments, the repetition level (number of repetitions) may vary according to the specific signal being transmitted, the specific UE transmitting the signal (e.g., different UEs may have different extended coverage levels), and / or the signal environment (e.g., indicating different numbers of repetitions may be used to obtain the same link budget regardless of whether CSI indicates that the channel quality has changed). In each of these figures, the scheduling request and HARQ ACK / NACK are transmitted on the same or different sets of PRBs. The SR and ACK / NACK may be transmitted in the same PRB but with different resources (e.g., different spreading codes) to avoid conflict. For Figures 3A to 3DThe number of PRBs for a given PUCCH transmission can vary and is between 1 - 4 PRBs, depending on the UCI format indicated by the eNB. If the UE is an MTC UE, where the communication spectrum between the UE and the eNB can be restricted relative to the bandwidth spectrum over which the eNB can communicate (e.g., 1.4 MHz), then the PRBs used can be restricted. Although shown as being transmitted in a single set of constant resources, in some embodiments, frequency hopping can occur between time slots. In this case, various signals can be transmitted on different resources in different time slots. The resources used by the UE during each transmission, whether or not frequency hopping is used, can be predetermined by the standard or assigned by the eNB for the UE, e.g., using RRC signaling.

[0037] In Figure 3A the UL subframe 300 of SR for example, the first set of UL subframes A covers the region from the first subframe (where the scheduling request 302 may be first transmitted) SF AN to the subframe just before the start of the HARQ ACK / NACK 304 subframe SF SR to SF AN - 1) (SF SR to SF AN - 1). That is, in the first set of subframes A, the scheduling request 302 can be transmitted via consecutive subframes, while the HARQ ACK / NACK 304 cannot be transmitted. In some embodiments, in each of these subframes, the scheduling request 302 can be repeated on the same set of resources. In Figure 3A the Figure 3A the repetition level can be the same or different between the scheduling request 302 and the HARQ ACK / NACK 304.

[0038] The second set of UL subframes B covers the region from the first subframe (where the HARQ ACK / NACK 304 is to be transmitted) SF AN to the last subframe (where the scheduling request 302 is to be transmitted) RL SR - 1) (SF AN to SF SR + RL SR - 1). In the second set of subframes B, both the scheduling request 302 and the HARQ ACK / NACK 304 can be scheduled to be transmitted on different resources and thus overlap in time.

[0039] The third set of UL subframes C covers the region from the first subframe after the last subframe (where the scheduling request 302 can be transmitted) SF SR + RL SR to the last subframe (where the HARQ ACK / NACK 304 can be transmitted) RL AN - 1) (SF SR + RL SR to SF AN+RL AN -1). Therefore, in the third set of subframes C, the HARQ ACK / NACK 304 can be transmitted via consecutive subframes on the same set of resources, while the scheduling request cannot be transmitted. Therefore, the HARQ ACK / NACK repetition starts after the start subframe of the scheduling request repetition and ends after the last subframe of the scheduling request repetition.

[0040] Although the first set of UL subframes A and the third set of UL subframes C do not pose a problem in terms of overlap as only one of them is in the PUCCH signal, in the second set of UL subframes B, the scheduling request 302 and the HARQ ACK / NACK 304 can be transmitted on the corresponding resources and both will be transmitted. To overcome this problem, the HARQ ACK / NACK 304 can be transmitted in the resources allocated to the scheduling request 302 rather than the resources associated with the HARQ ACK / NACK 304 in this area. Although the eNB may expect the HARQ ACK / NACK on the resources allocated to the HARQ ACK / NACK, in these subframes for the UE in the enhanced mode, the eNB can first check the resources for the scheduling request to determine if there is any PUCCH signal in the resources for the scheduling request. If a PUCCH signal exists in the resources for the scheduling request, the eNB can receive the PUCCH signal instead of tuning to the resources for the HARQ ACK / NACK to attempt to receive the HARQ ACK / NACK. The value that the scheduling request can take can be 0 (no signal is transmitted on the allocated resources) or 1 (a signal exists in the allocated resources). The value that the HARQ ACK / NACK can take can be +1 or -1. If energy is detected in the resources allocated to the scheduling request, regardless of what the energy is, the eNB can initially identify the energy as coming from the UE's scheduling request. In some embodiments, only after successfully decoding the signal in the resources for the scheduling request can the eNB determine that the information is the HARQ ACK / NACK. In other embodiments, the eNB can retain the information that the HARQ ACK / NACK is scheduled to be transmitted by the UE in the second set of subframes B, and thus any transmission on the resources for the scheduling request is also the HARQ ACK / NACK indicating the existence of the scheduling request. Therefore, the UE can forgo the scheduling request transmission and instead transmit the HARQ ACK / NACK in the resources for the scheduling request because as the scheduling request, the eNB can interpret the existence of the HARQ ACK / NACK in the resources for the scheduling request. Note that if no scheduling request is indicated in the resources associated with the scheduling request, no overlap occurs. Therefore, the UE can transmit only one of the overlapping scheduling request 302 and HARQ ACK / NACK 304 signals in the subframes (where the signals overlap), and transmit either the scheduling request 302 or the HARQ ACK / NACK 304 but not both in the subframes (where one of the scheduling request 302 and HARQ ACK / NACK 304 signals does not overlap with the other of the scheduling request 302 and HARQ ACK / NACK 304 signals).

[0041] Figure 3B Shows UL subframe 320, where the first set of UL subframes A covers from the first subframe (where the scheduling request 322 can be transmitted first) SFSR to subframe SF just before the start of HARQ ACK / NACK 324 subframe AN in the region of -1 (SF SR to SF AN -1). As described above, the scheduling request 302 can be transmitted via consecutive subframes on the same set of PRBs, while the HARQ ACK / NACK 304 cannot be transmitted.

[0042] The second set of UL subframes B covers the region from the first subframe (where HARQ ACK / NACK 324 is to be transmitted) SF AN to the last subframe (where HARQ ACK / NACK 324 can be transmitted) RL AN -1 (SF AN to SF AN + RL AN -1). As described above, in the second set of subframes B, both the scheduling request 322 and the HARQ ACK / NACK 324 can be time-overlapped on different resources. In Figure 3B , the repetition levels can be different between the scheduling request 322 and the HARQ ACK / NACK 324, where the repetition level of the scheduling request 322 is greater than that of the HARQ ACK / NACK 324.

[0043] The third set of UL subframes C covers the region from the first subframe after the last subframe (where HARQ ACK / NACK 324 can be transmitted) SF SR + RL SR to the last subframe (where the scheduling request 322 can be transmitted) RL SR -1 (SF SR + RL AN to SF SR + RL SR -1). Therefore, in the third set of subframes C, the HARQ ACK / NACK 324 is no longer transmissible, and the scheduling request 322 can continue to be transmitted.

[0044] In a manner similar to the above, the HARQ ACK / NACK 324 can be transmitted in the second set of subframes B in the resources associated with the scheduling request 322 instead of the resources associated with the HARQ ACK / NACK 324. Thus, in this example, the transmission of the scheduling request 322 can surround the transmission of the HARQ ACK / NACK 324 on the resources of the scheduling request 322, where the transmission of the HARQ ACK / NACK 324 in the second set of subframes B replaces the transmission of the scheduling request 322. As described above, the eNB can initially identify the energy as being from the UE's scheduling request. Only after successfully decoding the signal in the resources for the scheduling request can the eNB determine that the information is HARQ ACK / NACK.

[0045] In Figure 3C the UL subframe 340 of AN the first set of UL subframes A covers the region from the first subframe (where the HARQ ACK / NACK 344 can be first transmitted) SF SR to the subframe just before the start of the scheduling request 342 SF AN - 1 (SF SR to SF Figure 3C In

[0046] the second set of UL subframes B covers the region from the first subframe (where the scheduling request 342 is to be transmitted) RL SR to the last subframe (where the HARQ ACK / NACK 344 is to be transmitted) SF AN - 1 (SF SR to SF AN + RL AN - 1). In the second set of subframes B, both the scheduling request 342 and the HARQ ACK / NACK 344 can be scheduled to be transmitted on different resources and thus overlap in time.

[0047] The third set of UL subframes C covers the region from the first subframe after the last subframe (where the HARQ ACK / NACK 344 can be transmitted) SF AN + RL AN to the last subframe (where the scheduling request 342 can be transmitted) RL SR - 1 (SF AN + RL AN to SF SR + RL SR-1). Therefore, in the third group of subframes C, the scheduling request 342 can continue to be transmitted on the same set of resources, while the HARQ ACK / NACK 344 cannot be transmitted. Therefore, the scheduling request repetition starts after the start subframe of the HARQ ACK / NACK repetition and ends after the last subframe of the HARQ ACK / NACK repetition.

[0048] Similar to the above, the HARQ ACK / NACK 344 can be transmitted in the second group of subframes B in the resources associated with the scheduling request 342 instead of the resources associated with the HARQ ACK / NACK 344. Therefore, the UE can abandon the scheduling request transmission and instead transmit the HARQ ACK / NACK in the resources of the scheduling request, because as a scheduling request, the eNB can interpret the presence of the HARQ ACK / NACK in the resources of the scheduling request.

[0049] Figure 3D The UL subframe 360 is shown, where the first group of UL subframes A covers the area from the first subframe (where the HARQ ACK / NACK 364 can be transmitted first) SF AN to the subframe just before the start of the scheduling request 362 SF SR -1 (SF AN to SF SR -1). As described above, the HARQ ACK / NACK 364 can be transmitted on the same set of resources via consecutive subframes, while the scheduling request 362 cannot be transmitted. In Figure 3D , the repetition levels can be different between the scheduling request 362 and the HARQ ACK / NACK 364, where the repetition level of the HARQ ACK / NACK 364 is greater than that of the scheduling request 362.

[0050] The second group of UL subframes B covers the area from the first subframe (where the scheduling request 362 can be transmitted) SF SR to the last subframe (where the scheduling request 362 can be transmitted) RL SR -1 (SF SR to SF SR + RL SR -1). As described above, in the second group of subframes B, both the scheduling request 362 and the HARQ ACK / NACK 364 can overlap in time on different resources.

[0051] The third group of UL subframes C covers the area from the first subframe after the last subframe (where the scheduling request 362 can be transmitted) SF SR + RL SR to the last subframe (where the HARQ ACK / NACK 364 can be transmitted) RL AN -1 (SFSR +RL SR to SF AN +RL AN -1). Therefore, in the third set of subframes C, the scheduling request 362 is no longer transmittable, and the HARQ ACK / NACK 364 can continue to be transmitted.

[0052] In a manner similar to the above, the HARQ ACK / NACK 364 can be transmitted in the second set of subframes B in the resources associated with the scheduling request 362 instead of the resources associated with the HARQ ACK / NACK 364. Therefore, in this example, the transmission of the scheduling request 362 can be around the transmission of the scheduling request 362 on the PRB of the scheduling request 362, where the transmission of the HARQ ACK / NACK 364 in the second set of subframes B replaces the transmission of the scheduling request 362. However, in this case, the separate scheduling request 362 is not transmitted.

[0053] Figures 4A to 4D The figure illustrates an uplink subframe according to some embodiments. Figures 4A to 4D Shows overlapping uplink transmissions in an enhanced mode UE such as an MTC UE as Figure 1 or Figure 2 shown. Similar to Figures 3A to 3D , there are three sets of UL subframes A, B, C, where only one set of subframes contains an overlap between different uplink signals. Figures 4A to 4D Variously includes the start subframe for PUSCH data SF DATA of, the HARQ ACK / NACK SF AN , and the end subframe for PUSCH data SF DATA and HARQ ACK / NACK RL ANRepetition level (number of repetitions). In some embodiments, the repetition level (number of repetitions) may be the same across different signals and / or different UEs. In some embodiments, the repetition level (number of repetitions) may vary according to the specific signal being transmitted, the specific UE transmitting the signal (e.g., different UEs may have different extended coverage levels), and / or the signal environment (e.g., indicating different numbers of repetitions may be used to achieve the same link budget regardless of whether the CSI indicates that the channel quality has changed). In each of these figures, PUSCH data and HARQ ACK / NACK are transmitted on different sets of resources. If the UE is an MTC UE, where the communication spectrum between the UE and the eNB may be restricted relative to the bandwidth spectrum over which the eNB can communicate (e.g., 1.4 MHz), then the resources used may be restricted. Although shown as being transmitted in a single set of constant resources, in some embodiments, frequency jitter may occur between time slots. In this case, various signals may be transmitted on different resources in different time slots. The resources used by the UE during each transmission, whether frequency jitter is used or not, may be predetermined by a standard or assigned by the eNB for the UE, e.g., using RRC signaling.

[0054] In Figure 4A the UL subframe 400 of DATA for example, the first set of UL subframes A covers the region from the first subframe (where PUSCH data 402 may be transmitted first) SF AN to the subframe just before the start of the HARQ ACK / NACK 404 subframe SF DATA to SF AN -1 (SF DATA to SF AN -1). That is, in the first set of subframes A, the PUSCH data 402 may be transmitted via consecutive subframes, while the HARQ ACK / NACK 404 is not transmitted. In some embodiments, in each of these subframes, the PUSCH data 402 may be repeated on the same set of resources.

[0055] The second set of UL subframes B covers the region between the first subframe (where the HARQ ACK / NACK 404 is to be transmitted) SF AN to the last subframe (where the PUSCH data 402 is to be transmitted) RL DATA -1 (SF AN to SF DATA + RL DATA -1). In the second set of subframes B, both the PUSCH data 402 and the HARQ ACK / NACK 404 may be scheduled to be transmitted on different resources and thus overlap in time.

[0056] The third set of UL subframes C covers the region from the first subframe after the last subframe (where the PUSCH data 402 may be transmitted) SF DATA+RL DATA to the last subframe (where HARQ ACK / NACK 404 can be transmitted) RL AN -1 region (SF DATA +RL DATA to SF AN +RL AN -1). Therefore, in the third set of subframes C, HARQ ACK / NACK 404 can be transmitted via consecutive subframes on the same set of resources, while PUSCH data cannot be transmitted. Therefore, the HARQ ACK / NACK repetition starts after the start subframe of the PUSCH data repetition and ends after the last subframe of the PUSCH data repetition.

[0057] To overcome the overlap in the second set of UL subframes B, HARQ ACK / NACK 404 can be transmitted in the resources allocated to PUSCH data 402 rather than in the PRBs associated with HARQ ACK / NACK 404 in this region. However, different from Figures 3A to 3D the embodiment shown, PUSCH data 402 can still be transmitted on the resources allocated to PUSCH data 402. According to the procedure specified in Section 5.2.2.6 of 3GPP TS 36.212, HARQ ACK / NACK 404 can be encoded and punctured to form the data symbols of PUSCH data 402. In this process, some of the data symbols of PUSCH data 402 can be replaced by ACK / NACK encoded symbols. Section 5.2.2.8 of 3GPP TS 36.212 specifies which data symbols can (and which data symbols cannot) be replaced by ACK / NACK symbols. In some embodiments, the punctured data symbols can be adjacent to the DM-RS symbols of PUSCH data 402. In some embodiments, although the PUSCH data may include CSI reports, the HARQ ACK / NACK404 symbols can puncture the data symbols adjacent to the DM-RS symbols of PUSCH data 402 and be transmitted together with PUSCH data 402 on the resources associated with PUSCH data 402.

[0058] In some embodiments, the eNB may determine that the information in the PUSCH data 402 includes the HARQ ACK / NACK 404 only after successfully decoding the signal in the resources for the PUSCH data 402. In other embodiments, the eNB may retain the information that the HARQ ACK / NACK is scheduled to be transmitted by the UE in the second set of subframes B, and thus any transmission on the resources of the PUSCH data 402 includes the HARQ ACK / NACK 404. Accordingly, the UE may forego the transmission of the HARQ ACK / NACK 404 on the resources associated with the HARQ ACK / NACK 404 and instead transmit the HARQ ACK / NACK 404 and the PUSCH data 402 in the resources of the PUSCH data 402. Accordingly, the UE may transmit only one of the separate overlapping PUSCH data 402 and HARQ ACK / NACK 404 signals in a subframe where the signals overlap.

[0059] Figure 4B Shows a UL subframe 420, where the first set of UL subframes A covers the region from the first subframe (where the PUSCH data 422 may be first transmitted) SF DATA to the subframe just before the start of the HARQ ACK / NACK 424 subframe SF AN -1 (SF DATA to SF AN -1). As described above, the PUSCH data 422 may be transmitted via consecutive subframes on the same set of resources, while the HARQ ACK / NACK 424 may not be transmitted.

[0060] The second set of UL subframes B covers the region from the first subframe (where the HARQ ACK / NACK 424 is to be transmitted) SF AN to the last subframe (where the HARQ ACK / NACK 424 may be transmitted) RL AN -1 (SF AN to SF AN + RL AN -1). As described above, in the second set of subframes B, both the PUSCH data 422 and the HARQ ACK / NACK 424 may overlap in time on different resources.

[0061] The third set of UL subframes C covers the region from the first subframe after the last subframe (where the HARQ ACK / NACK 424 may be transmitted) SF DATA + RL DATA to the last subframe (where the PUSCH data 422 may be transmitted) RL DATA -1 (SF AN + RL AN to SFDATA +RL DATA - 1). Therefore, in the third set of subframes C, the HARQ ACK / NACK 424 is no longer transmittable, and the PUSCH data 422 can continue to be transmitted.

[0062] In a manner similar to the above, the HARQ ACK / NACK 424 can be transmitted in the second set of subframes B in the resources associated with the PUSCH data 422 instead of the resources associated with the HARQ ACK / NACK 424. The HARQ ACK / NACK 424 can be embedded into the PUSCH data 422. The HARQ ACK / NACK 424 can be encoded and punctured to form the data symbols of the PUSCH data 422. In this example, the transmission of the PUSCH data 422 can be around the transmission of the HARQ ACK / NACK 424 on the resources of the PUSCH data 422, where the transmission of the HARQ ACK / NACK 424 in the second set of subframes B replaces the transmission of the PUSCH data 422.

[0063] In Figure 4C the UL subframe 440, the first set of UL subframes A covers the region from the first subframe (where the HARQ ACK / NACK 444 subframe can be transmitted first) SF AN to the subframe just before the start of the PUSCH data 442 SF DATA - 1 (SF AN to SF DATA - 1). In this region, the HARQ ACK / NACK 444 can be transmitted via consecutive subframes on the same set of resources, while the PUSCH data 442 cannot be transmitted.

[0064] The second set of UL subframes B covers the region from the first subframe (where the PUSCH data 442 is to be transmitted) RL DATA to the last subframe (where the HARQ ACK / NACK 444 is to be transmitted) SF AN - 1 (SF DATA to SF AN +RL AN - 1). In the second set of subframes B, both the PUSCH data 442 and the HARQ ACK / NACK 444 can be scheduled to be transmitted on different resources and thus overlap in time.

[0065] The third set of UL subframes C covers the region from the first subframe after the last subframe (where the HARQ ACK / NACK 444 can be transmitted) SF AN +RL AN to the last subframe (where the PUSCH data 442 can be transmitted) RL DATA-1 region (SF AN +RL AN to SF DATA +RL DATA -1). Thus, in the third set of subframes C, the PUSCH data 442 can be transmitted via consecutive subframes on the same set of resources, while the HARQ ACK / NACK 444 is no longer transmissible. Therefore, the repetition of the PUSCH data starts after the start subframe of the HARQ ACK / NACK repetition and ends after the last subframe of the HARQ ACK / NACK repetition.

[0066] Similar to the above, the HARQ ACK / NACK 444 can be transmitted in the second set of subframes B in the resources associated with the PUSCH data 442 instead of the resources associated with the HARQ ACK / NACK 444. The HARQ ACK / NACK 444 can be embedded into the PUSCH data 442. The HARQ ACK / NACK 424 can be encoded and punctured to form the data symbols of the PUSCH data 422. Thus, the UE can abandon the PUSCH data transmission and instead transmit the HARQ ACK / NACK in the resources of the PUSCH data, because as PUSCH data, the eNB is able to interpret the presence of the HARQ ACK / NACK in the resources of the PUSCH data.

[0067] Figure 4D The UL subframe 460 is shown, where the first set of UL subframes A covers from the first subframe (where the HARQ ACK / NACK464 can be first transmitted) SF AN to the subframe just before the start of the PUSCH data 462 SF DATA -1 region (SF AN to SF DATA -1). As described above, the HARQ ACK / NACK 464 can be transmitted via consecutive subframes on the same set of resources, while the PUSCH data 462 is not transmissible.

[0068] The second set of UL subframes B covers from the first subframe (where the PUSCH data 462 is transmissible) SF DATA to the last subframe (where the PUSCH data 462 is transmissible) RL DATA -1 region (SF DATA to SF DATA +RL DATA -1). As described above, in the second set of subframes B, both the PUSCH data 462 and the HARQ ACK / NACK 464 can overlap in time on different resources.

[0069] The third group of UL subframe C covers the first subframe after the last subframe (where PUSCH data 462 can be transmitted) SF DATA +RL DATA to the last subframe (where HARQ ACK / NACK 464 can be transmitted) RL AN -1 region (SF DATA +RL DATA to SF AN +RL AN -1). Therefore, in the third group of subframe C, PUSCH data 462 is no longer transmissible, and HARQ ACK / NACK 464 can continue to be transmitted.

[0070] In a manner similar to the above, HARQ ACK / NACK 464 can be transmitted in the second group of subframe B in the resources associated with PUSCH data 462 rather than the resources associated with HARQ ACK / NACK464. Therefore, in this example, the transmission of HARQACK / NACK data 462 can surround the transmission of PUSCH data 462 on the resources of PUSCH data 462, where the transmission of HARQ ACK / NACK 464 in the second group of subframe B replaces the transmission of PUSCH data 462.

[0071] Figure 5 A flowchart illustrating a method for uplink collision handling for enhanced coverage mode UEs according to some embodiments. In method 500, at operation 502, the UE can receive an allocation of resources for various PUCCH and PUSCH signals. The allocation can be predetermined via a specification or can be provided to the UE, for example, using RRC or other control signaling. The UE can be a normal UE with a bandwidth of allegedly 20 MHz, or an MTC UE with its bandwidth limited to 1.4 MHz. Other restricted bandwidths supported by LTE can be used, such as 3 MHz, 5 MHz, 10 MHz, or 15 MHz or bandwidths less than 1.4 MHz.

[0072] At operation 504, the UE can determine whether to transmit multiple uplink signals to the eNB and whether the signals overlap in time. The signals can be transmitted in the same subframe but are assigned different resources. The signals can be different PUCCH signals or a PUCCH signal and a PUSCH signal. Specifically, the UE can determine whether the PUCCH signal includes a scheduling request and HARQ ACK / NACK or HARQACK / NACK and PUSCH data (possibly with CSI data).

[0073] Once the UE determines that an overlap is about to occur, at operation 506, the UE may select only one of the uplink signals to transmit in a subframe. This selection may be restricted by the 3GPP specifications such that multiple uplink signals cannot be transmitted to the eNB simultaneously. The selection and manner of determining the transmission may depend on the type of uplink signals in the same subframe. For example, since a scheduling request can typically be indicated by the presence of a HARQ ACK / NACK, the transmission of a separate scheduling request may be redundant. Similarly, since a HARQ ACK / NACK can be combined in a PUSCH data signal, the transmission of a separate HARQ ACK / NACK for the HARQ ACK / NACK may be redundant.

[0074] At operation 508, the selected uplink signal is transmitted by the UE to the eNB. As described above, if at operation 504, an overlap between a scheduling request and a HARQ ACK / NACK is determined, the HARQ ACK / NACK rather than the scheduling request may be transmitted. However, the HARQ ACK / NACK may be transmitted in the resources of the scheduling request rather than the HARQ ACK / NACK, thereby allowing the HARQ ACK / NACK to act as a scheduling request to the eNB. If at operation 504, an overlap between PUSCH data and a HARQ ACK / NACK is determined, the PUSCH data rather than the HARQ ACK / NACK may be transmitted. However, the HARQ ACK / NACK may be transmitted in the resources of the PUSCH data by puncturing the data symbols around the DM-RS of the PUSCH data. Thus, the UE may transmit both the PUSCH data and the HARQ ACK / NACK in the resources of the PUSCH data while suppressing the transmission of the HARQ ACK / NACK in the resources of the HARQ ACK / NACK.

[0075] The UE may then determine at operation 510 whether the overlap has ended. For a UE in normal mode, only one PUCCH or PUSCH signal can be transmitted to convey a specific piece of information. However, for a UE in enhanced mode, the same multiple PUCCH or PUSCH signals can be transmitted in consecutive subframes so that the eNB can accumulate a link budget sufficient to allow the eNB to decode the signals. Therefore, the UE may continue to transmit only the selected signal as long as the overlap continues to occur between the resources allocated to different signals.

[0076] At operation 512, the UE may determine that the overlap ends - i.e., only one of the signals is going to be transmitted on the appropriate resources. In some embodiments, the signal may continue to be transmitted from a previous subframe for a predetermined number of repetitions, depending on the enhancement level of the UE (e.g., whether an increase of 5 dB, 10 dB, 20 dB is desired to achieve a predetermined link budget). In some embodiments, the signal may be transmitted even if it has not been transmitted on a previous subframe. This allows the UE to maintain the low cubic metric (CM) single-carrier nature of the transmitted signal, where the transmitted signal is repeated across multiple subframes for various physical channels to allow signal energy to accumulate at the receiver, while avoiding potential collisions caused by the repetition when the UE is in an enhanced coverage mode and has a limited link budget.

[0077] Various examples of the present disclosure are provided below. These examples are not intended to limit the disclosure herein in any way. In Example 1, the UE includes a transceiver configured to communicate with an eNB and processing circuitry. The processing circuitry is configured to: configure the UE to be in a normal coverage mode or an enhanced coverage (EC) mode; when the UE is in the EC mode, determine whether a physical uplink control channel (PUCCH) signal and an uplink signal (another PUCCH signal or a physical uplink shared channel (PUSCH) signal) assigned to different physical resource blocks (resources) overlap in a particular subframe to form an overlapping signal; select one of the overlapping signals for transmission during the particular subframe; and configure the transceiver to transmit the one overlapping signal on the resources assigned to the other overlapping signal rather than on the resources assigned to the one overlapping signal.

[0078] In Example 2, the subject matter of Example 1 optionally includes any one or both of the following: processing circuitry configured to configure the transceiver to transmit at least one of the overlapping signals in another subframe in which at least one of the overlapping signals does not overlap with the other overlapping signal.

[0079] In Example 3, the subject matter of Example 1 to 2, or any combination thereof, optionally includes processing circuitry configured to configure the transceiver to transmit at least one of the overlapping signals in consecutive subframes including the particular subframe.

[0080] In Example 4, the subject matter of Example 3 optionally includes processing circuitry configured to configure the transceiver to transmit the other overlapping signal in a subframe surrounding one of the overlapping signals.

[0081] In Example 5, the subject matter of one or any combination of Examples 1 to 4 optionally includes processing circuitry configured to configure a transceiver to suppress transmission of one of the overlapping signals on resources allocated to another of the overlapping signals in the overlapping signals.

[0082] In Example 6, the subject matter of Example 5 optionally includes one of the overlapping signals that includes an acknowledgement / negative acknowledgement (ACK / NACK), and another of the overlapping signals includes a scheduling request (SR).

[0083] In Example 7, the subject matter of one or any combination of Examples 1 to 6 optionally includes processing circuitry configured to configure a transceiver to transmit one of the overlapping signals on resources allocated to another of the overlapping signals in the overlapping signals.

[0084] In Example 8, the subject matter of Example 7 optionally includes one of the overlapping signals that includes an acknowledgement / negative acknowledgement (ACK / NACK), and another of the overlapping signals includes a PUSCH signal that includes data symbols surrounding a demodulation reference (DM-RS) symbol, and the processing circuitry is further configured to puncture data symbols adjacent to the PUSCH DM-RS symbol and insert the ACK / NACK.

[0085] In Example 9, the subject matter of one or any combination of Examples 1 to 8 optionally includes a UE that is a machine type communication (MTC) UE restricted to communicate with an eNB via a limited set of subbands of a bandwidth spectrum over which the eNB is capable of communicating, and repeating at least one of a PUCCH signal and an uplink signal across multiple subframes to form an overlapping signal.

[0086] In Example 10, the subject matter of one or any combination of Examples 1 to 9 optionally includes an antenna configured to transmit and receive communication between a transceiver and an eNB.

[0087] In Example 11, an apparatus of an eNB includes processing circuitry configured to: determine which of a normal coverage mode and an enhanced coverage (EC) mode a UE is in; configure a transceiver to receive multiple signals from the UE on the same predetermined set of physical resource blocks (PRBs) in different subframes, the multiple signals in the subframes being expected to provide the same information in response to determining that the UE is in the EC mode; decode the multiple signals; detect that a signal in at least one of the subframes is different from a signal in another of the subframes; and determine that the signal in at least one of the subframes includes an overlapping signal of the set of different PRBs received on the predetermined set of PRBs rather than on a different set of PRBs.

[0088] In Example 12, the subject matter of Example 11 optionally includes a plurality of signals, which includes one of a Physical Uplink Control Channel (PUCCH) signal and a Physical Uplink Shared Channel (PUSCH) signal, and the signal in at least one of the subframes includes another PUCCH signal.

[0089] In Example 13, the subject matter of one or any combination of Examples 11 to 12 optionally includes processing circuitry configured to configure a transceiver to receive a plurality of signals in consecutive subframes including at least one of the subframes.

[0090] In Example 14, the subject matter of Example 13 optionally includes processing circuitry further configured to configure a transceiver to receive the signal in at least one of the subframes in subframes surrounding at least one of the subframes.

[0091] In Example 15, the subject matter of one or any combination of Examples 11 to 14 optionally includes the signal in at least one of the subframes, rather than the signal in another of the subframes, being received in at least one of the subframes.

[0092] In Example 16, the subject matter of Example 15 optionally includes the signal in at least one of the subframes, which includes an Acknowledgment / Negative Acknowledgment (ACK / NACK), and the signal in another of the subframes includes a Scheduling Request (SR).

[0093] In Example 17, the subject matter of one or any combination of Examples 11 to 16 optionally includes the signal in at least one of the subframes being received in at least one of the subframes in addition to the signal in another of the subframes.

[0094] In Example 18, the subject matter of Example 17 optionally includes the signal in at least one of the subframes, which includes an Acknowledgment / Negative Acknowledgment (ACK / NACK), and the signal in another of the subframes includes a PUSCH signal, the PUSCH signal including data symbols punctured adjacent to Demodulation Reference (DM-RS) symbols, with the ACK / NACK inserted therein.

[0095] In Example 19, the subject matter of one or any combination of Examples 11 to 18 optionally includes a Machine-Type Communication (MTC) UE for which the UE is restricted to communicating with an eNB via a limited set of subbands of a bandwidth spectrum via which the eNB is capable of communicating, and repeating at least one of the plurality of signals across a plurality of subframes.

[0096] In Example 20, a non-transitory computer-readable storage medium stores instructions for execution by one or more processors of a UE to configure the UE to communicate with an eNB. The one or more processors configure the UE to operate in an enhanced coverage (UE) mode; determine that a physical uplink control channel (PUCCH) signal assigned to a first physical resource block (PRB) and an uplink signal assigned to a second PRB different from the first PRB overlap in a specific subframe, the uplink signal including one of another PUCCH signal and a physical uplink shared channel (PUSCH) signal; and transmit the PUCCH signal on the second PRB rather than on the first PRB in the specific subframe.

[0097] In Example 21, the subject matter of Example 20 optionally includes a PUCCH signal that includes an acknowledgement / negative acknowledgement (ACK / NACK), the uplink signal includes a scheduling request (SR), and the ACK / NACK is transmitted instead of the SR.

[0098] In Example 22, the subject matter of one or any combination of Examples 20 to 21 optionally includes a PUCCH signal that includes an acknowledgement / negative acknowledgement (ACK / NACK), the uplink signal includes a PUSCH signal, and data symbols of the PUSCH signal are punctured adjacent to demodulation reference (DM-RS) symbols, and the ACK / NACK is inserted.

[0099] In Example 23, the subject matter of Example 22 optionally includes a PUSCH signal that includes channel state information (CSI).

[0100] Although embodiments have been described with reference to specific example embodiments, it will be apparent that various modifications and changes can be made to these embodiments without departing from the broader spirit and scope of the disclosure. Accordingly, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense. The accompanying drawings, which form a part of this specification, illustrate specific embodiments in which the subject matter can be practiced by way of example and not by way of limitation. The illustrated embodiments are described in sufficient detail to enable those skilled in the art to practice the teachings disclosed herein. Other embodiments can be utilized and derived therefrom, such that structural and logical substitutions and changes can be made without departing from the scope of the disclosure. Accordingly, this detailed description is not to be considered in a limiting sense, and the scope of various embodiments is defined only by the appended claims and the full scope of equivalents to which such claims are entitled.

[0101] Although specific embodiments have been illustrated and described herein, it should be recognized that any configuration calculated to achieve the same purpose can be substituted for the specific embodiments shown. The disclosure is intended to cover any and all adaptations and variations of various embodiments. Combinations of the above embodiments and other embodiments not specifically described herein will be apparent to those skilled in the art who have reviewed the foregoing description.

[0102] In this document, the terms "a" or "an" are used as in patent documents to include one or more than one, regardless of any other instances or uses of "at least one" or "one or more". In this document, the term "or" is used to refer to a non-exclusive or, such that "A or B" includes "A but not B", "B but not A", and "A and B", unless otherwise indicated. In this document, the terms "comprising" and "wherein" are used as the plain English equivalents of the corresponding terms "including" and "in which". Also, in the appended claims, the terms "comprising" and "including" are open-ended, i.e., a system, UE, article, composition, expression, process that includes elements other than those listed after this term in the claim is still considered to fall within the scope of that claim. Further, in the appended claims, the terms "first", "second", "third", etc. are used merely as labels and are not intended to imply a numerical requirement for their objects.

[0103] A summary of the present disclosure that complies with 37 C.F.R. § 1.72(b) is provided, which requires a summary that will allow the reader to quickly determine the nature of the technical disclosure. The summary is presented in a manner that it will not be used to interpret or limit the scope or meaning of the claims. Additionally, in the foregoing detailed description, various features are grouped together in a single embodiment to simplify the disclosure. The method of the present disclosure is not to be construed as reflecting an invention in which the claimed embodiments require more features than are expressly recited in each claim. Rather, as the appended claims reflect, the inventive subject matter lies in fewer features than all of the features of a single disclosed embodiment. Accordingly, the appended claims are hereby incorporated into the detailed description, where each claim stands on its own as a separate embodiment.

Claims

1. A user equipment UE, comprising: A transceiver configured to communicate with a base station BS in a network; And Processing circuitry configured to: In response to the UE being in enhanced coverage (EC) mode, determine whether different overlapping signals are to be transmitted on a physical uplink control channel (PUCCH) in a specific subframe, wherein a first overlapping signal is an acknowledgement / negative acknowledgement (ACK / NACK), and a second overlapping signal is a scheduling request (SR); For transmission during the specific subframe, encode the ACK / NACK on a first resource of the PUCCH rather than on a second resource, wherein the first resource has been previously allocated for the scheduling request during the specific subframe, and wherein the second resource has been previously allocated for the ACK / NACK, and wherein the scheduling request is signaled to the base station by the presence of energy on the first resource.

2. The user equipment according to claim 1, wherein the different overlapping signals are configured with corresponding repetition levels, each of the repetition levels being greater than or equal to 1.

3. The user equipment according to claim 1, wherein the processing circuitry is further configured to: Encode the SR in another subframe for transmission via the transceiver, wherein the SR does not overlap with the ACK / NACK in the another subframe.

4. The user equipment according to claim 1, wherein the processing circuitry is further configured to: Encode the SR in subframes surrounding the particular subframe for transmission via the transceiver.

5. The user equipment according to claim 1, wherein the BS is capable of communicating via a bandwidth spectrum, wherein the UE is a machine type communication MTC UE restricted to communicate with the BS via a limited set of subbands of the bandwidth spectrum, wherein at least the scheduling request is repeated across multiple subframes.

6. The user equipment according to claim 1, wherein the processing circuitry is further configured to: After the encoding, decode a scheduling grant received from the BS via the transceiver, wherein the scheduling grant is signaled in response to the scheduling request signaled by the presence of the energy on the first resource.

7. The user equipment according to claim 1, wherein the processing circuitry is further configured to: In response to decoding the scheduling grant, encode uplink data on a control channel resource identified by the scheduling grant.

8. The user equipment according to claim 1, further comprising: An antenna configured to transmit and receive communications between the transceiver and the BS.

9. A method for operating a user equipment UE, the method comprising: In response to the UE being in enhanced coverage (EC) mode, determine whether different overlapping signals are to be transmitted on a physical uplink control channel (PUCCH) in a specific subframe, wherein a first overlapping signal is an acknowledgement / negative acknowledgement (ACK / NACK), and a second overlapping signal is a scheduling request (SR); During the specific subframe, transmit the ACK / NACK on a first resource of the PUCCH rather than on a second resource, wherein the first resource has been previously allocated for the scheduling request during the specific subframe, and wherein the second resource has been previously allocated for the ACK / NACK, and wherein the scheduling request is signaled to the base station BS by the presence of energy on the first resource.

10. The method according to claim 9, wherein the different overlapping signals are configured with respective repetition levels, each of the repetition levels being greater than or equal to 1.

11. The method according to claim 9, further comprising: Transmit the SR in another subframe in which the SR does not overlap with the ACK / NACK.

12. The method according to claim 9, further comprising: Transmit the SR in subframes surrounding the specific subframe.

13. The method according to claim 9, wherein the BS is capable of communicating via a bandwidth spectrum, wherein the UE is a machine-type communication MTC UE restricted to communicate with the BS via a limited set of sub-bands of the bandwidth spectrum, wherein at least the scheduling request is repeated across multiple sub-frames.

14. The method according to claim 9, further comprising: After the transmission, decode a scheduling grant received from the BS, wherein the scheduling grant is in response to the scheduling request signaled by the presence of the energy on the first resource.

15. The method according to claim 9, further comprising: In response to decoding the scheduling grant, transmit uplink data on a control channel resource identified by the scheduling grant.

16. A base station BS, comprising: a transceiver configured to communicate with a user equipment UE in a network; And Processing circuitry configured to: Determine that a hybrid automatic repeat request (HARQ) ACK / NACK and a scheduling request are scheduled to overlap in a first subframe; In response to determining that the UE is in enhanced coverage (EC) mode, decode the HARQ ACK / NACK in a first resource of a physical uplink control channel (PUCCH), wherein the first resource has been allocated to the UE for a scheduling request (SR), and wherein The HARQ ACK / NACK is received on the PUCCH by the transceiver, and wherein when energy of the HARQ ACK / NACK is detected in the first resource of the PUCCH, the processing circuitry identifies the energy as the presence of the SR.

17. The base station according to claim 16, wherein the HARQ ACK / NACK and the SR are configured with respective repetition levels, each of the repetition levels being greater than or equal to 1.

18. The base station according to claim 16, wherein the UE is a machine-type communication MTC UE restricted to communicate with the BS via a limited set of sub-bands of a bandwidth spectrum, and the BS is capable of communicating via the bandwidth spectrum.

19. The base station according to claim 16, wherein the processing circuitry is further configured to: decode the energy to determine whether the information corresponding to the energy is an acknowledgement or denial of previously transmitted data.

20. The base station according to claim 16, further comprising: An interface for communicating with a core network.

21. A method for operating a base station BS, comprising: Determine that a hybrid acknowledgement / negative acknowledgement HARQ ACK / NACK and a scheduling request are scheduled to overlap in a first subframe; In response to determining that a user equipment UE is in an enhanced coverage EC mode, decode the HARQ ACK / NACK in a first resource of a physical uplink control channel PUCCH, wherein the first resource has been allocated to the UE for a scheduling request SR, wherein the HARQ ACK / NACK is received on the PUCCH, wherein, When the energy of the HARQ ACK / NACK is detected in the first resource of the PUCCH, identify the energy as the presence of the SR.

22. The method according to claim 21, wherein the HARQ ACK / NACK and the SR are configured with respective repetition levels, wherein each of the repetition levels is greater than or equal to 1.

23. The method according to claim 21, wherein the UE is a machine type communication MTC UE that is restricted to communicate with the BS via a limited set of subbands of a bandwidth spectrum, and the BS is capable of communicating via the bandwidth spectrum.

24. The method according to claim 21, wherein the method further comprises: Decode the energy to determine whether the information corresponding to the energy is an acknowledgement or denial of previously transmitted data.

25. A computer-readable storage medium storing instructions that, when executed by one or more processors of a user equipment UE, cause the UE to: In response to the UE being in an enhanced coverage EC mode, determine whether different overlapping signals are to be transmitted on a physical uplink control channel PUCCH in a specific subframe, wherein a first overlapping signal is an acknowledgement / negative acknowledgement ACK / NACK and a second overlapping signal is a scheduling request SR; For transmission during the specific subframe, encode the ACK / NACK on a first resource of the PUCCH rather than on a second resource, wherein the first resource has been previously allocated to the scheduling request during the specific subframe, and wherein the second resource has been previously allocated to the ACK / NACK, wherein, The scheduling request is signaled to the base station BS by the presence of energy on the first resource.

26. The computer-readable storage medium according to claim 25, wherein the different overlapping signals are configured with respective repetition levels, wherein each of the repetition levels is greater than or equal to 1.

27. The computer-readable storage medium according to claim 25, wherein the instructions, when executed by the one or more processors, cause the UE to: Encode the SR for transmission in another subframe, in which the SR does not overlap with the ACK / NACK.

28. The computer-readable storage medium according to claim 25, wherein when the instructions are executed by the one or more processors, the instructions cause the UE to: Encode the SR in subframes surrounding the specific subframe for transmission.

29. The computer-readable storage medium according to claim 25, wherein the BS is capable of communicating via a bandwidth spectrum, wherein the UE is a machine type communication MTC UE restricted to communicate with the BS via a limited set of subbands of the bandwidth spectrum, wherein at least the scheduling request is repeated across multiple subframes.

30. The computer-readable storage medium according to claim 25, wherein when the instructions are executed by the one or more processors, the instructions cause the UE to: After the encoding, decode a scheduling grant received from the BS, wherein the scheduling grant is in response to the scheduling request signaled by the presence of the energy on the first resource.

31. The computer-readable storage medium according to claim 25, wherein when the instructions are executed by the one or more processors, the instructions cause the UE to: In response to decoding the scheduling grant, encode uplink data on a control channel resource identified by the scheduling grant.

32. A computer-readable storage medium storing instructions that, when executed by one or more processors of a base station BS, cause the BS to: Determine that a hybrid acknowledgement / negative acknowledgement HARQ ACK / NACK and a scheduling request are scheduled to overlap in a first subframe; In response to determining that a user equipment UE is in an enhanced coverage EC mode, decode the HARQ ACK / NACK in a first resource of a physical uplink control channel PUCCH, wherein the first resource has been allocated to the UE for a scheduling request SR, wherein the HARQ ACK / NACK is received on the PUCCH, wherein, When the energy of the HARQ ACK / NACK is detected in the first resource of the PUCCH, identify the energy as the presence of the SR.

33. The computer-readable storage medium according to claim 32, wherein the HARQ ACK / NACK and the SR are configured with respective repetition levels, and each of the repetition levels is greater than or equal to 1.

34. The computer-readable storage medium according to claim 32, wherein the UE is a machine type communication MTC UE restricted to communicate with the BS via a limited set of subbands of a bandwidth spectrum, and the BS is capable of communicating via the bandwidth spectrum.

35. The computer-readable storage medium according to claim 32, wherein when the instructions are executed by the one or more processors, the instructions cause the BS to: decode the energy to determine whether information corresponding to the energy is an acknowledgement or denial of previously transmitted data.

36. A computer program product comprising a program code portion that, when the computer program product is run on one or more computing devices, is operative to perform the method according to any one of claims 9 to 15 or the method according to any one of claims 21 to 24.

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