Sounding Reference Signal Transmission in Low-Latency Wireless Transmission

Abstract

Methods, systems, and devices for wireless communications that support sounding reference signal (SRS) transmission in low-latency wireless transmissions are described. A set of shortened transmission time intervals (sTTIs) may be identified for uplink transmission of a first wireless service; the set of sTTIs is within a subframe time boundary of a subframe of a second wireless service having a TTI longer than the sTTI. Two or more sTTIs in the set of sTTIs may be used for SRS transmission within the subframe time boundary.

Description

[0001] This application is a divisional application of a Chinese patent application filed on December 12, 2017, with application number 201780078950.8 (PCT / US2017 / 065823), and invention name “Sounding Reference Signal Transmission in Low-Latency Wireless Transmission”.

[0002] Cross-references

[0003] This patent application claims U.S. Provisional Patent Application No. 62 / 438,160, entitled “Sounding Reference Signal Transmission In Low Latency Wireless Transmissions,” filed on December 22, 2016; and U.S. Patent Application No. 15 / 663,368, entitled “Sounding Reference Signal Transmission In Low Latency Wireless Transmissions,” filed by Hosseini et al. on July 28, 2017; each of the above applications being assigned to the assignee of this application. Background Art

[0004] In general, the following relates to wireless communications, and more specifically, to detection interference signal transmission in low-latency wireless transmissions.

[0005] Wireless multiple access technology has been used in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate at a city, country, region, or even global level. An example telecommunication standard is Long Term Evolution (LTE). LTE is designed to improve spectrum efficiency, reduce overhead, improve services, use new spectrum, and better integrate with other open standards. LTE can use OFDMA on the downlink (DL), single carrier frequency division multiple access (SC-FDMA) on the uplink (UL), and multiple input multiple output (MIMO) antenna technology.

[0006] In some examples, a wireless multiple access communication system may include several base stations, each of which simultaneously supports communication of multiple communication devices, which may be known as user equipment (UE). In an LTE or advanced LTE (LTE-A) network, a set of one or more base stations may define an eNodeB (eNB). In other examples (e.g., in next generation new radio (NR) or 5G networks), a wireless multiple access communication system may include several smart radio heads (RHs) communicating with several access node controllers (ANCs), wherein a set of one or more RHs communicating with the ANC defines a base station (e.g., eNB or gNB). A base station may communicate with a group of UEs on a downlink (DL) channel (e.g., for transmissions from a base station to a UE) and an uplink (UL) channel (e.g., for transmissions from a UE to a base station).

[0007] Base stations in some LTE or NR deployments may use different length transmission time intervals (TTIs) to send to one or more UEs, and the different lengths may be reduced in length relative to the traditional LTE TTI. This reduced length TTI may be referred to as a shortened TTI (sTTI), and users using sTTI communications may be referred to as low-latency users. sTTI may be a subset of one or more subframes corresponding to a traditional TTI subframe. The base station may allocate transmission resources for sTTI to the UE, which may include time resources, frequency resources, and one or more component carriers (CCs) to be used for sTTI transmission. The efficient allocation of these resources for data, control information, and reference signal transmission can help improve the efficiency of the wireless communication system. Summary of the invention

[0008] The described technology is about an improved method, system, device or apparatus for supporting the transmission of a sounding reference signal (SRS) in a low-latency wireless transmission. In general, the described technology provides for identifying a set of shortened transmission time intervals (sTTIs) for uplink transmission of a first wireless service (e.g., an ultra-reliable low-latency communication (URLLC) service); the sTTI set is located within a subframe time boundary of a subframe of a second wireless service (e.g., an enhanced mobile broadband (eMBB) service). Two or more sTTIs in the sTTI set can be used for SRS transmission within the subframe time boundary. In some examples, the subframe time boundary may include two slot boundaries (e.g., a 0.5 ms slot boundary in a 1 ms subframe), and the sTTI may be a slot-aligned sTTI so that the sTTI does not cross a slot boundary. An sTTI may have a length corresponding to a slot length in some examples. In other examples, multiple sTTIs may be located in each slot, each sTTI having two or three orthogonal frequency division multiplexing (OFDM) symbols.

[0009] In some cases, one OFDM symbol of each time slot may be identified for SRS transmission. In some examples, each time slot may include two 2-symbol sTTIs and one 3-symbol sTTI, and one OFDM symbol of each 3-symbol sTTI may be selected for SRS transmission. In some examples, two or more symbols of two or more 2-symbol sTTIs may be selected for SRS transmission. SRS transmission may be configured as aperiodic SRS transmission or periodic SRS transmission in some examples. In some cases, the bandwidth for SRS transmission may be selected to provide frequency diversity for channel estimation. In addition, in some cases, SRS transmission may be multiplexed with other transmissions, such as demodulation reference signal (DMRS) transmission or SRS transmission from other transmitters.

[0010] A wireless communication method is described. The method may include identifying a set of sTTIs for uplink transmission of a first wireless service, the set of sTTIs being within a subframe time boundary of a subframe of a second wireless service, identifying two or more sTTIs in the set of sTTIs for transmitting SRS transmissions within the subframe time boundary, and sending one or more SRS transmissions in at least one sTTI of the two or more sTTIs.

[0011] A wireless communication apparatus is described. The apparatus may include means for identifying a set of sTTIs for uplink transmission of a first wireless service, the set of sTTIs being within a subframe time boundary of a subframe of a second wireless service, means for identifying two or more sTTIs in the set of sTTIs for transmitting SRS transmissions within the subframe time boundary, and means for sending one or more SRS transmissions in at least one sTTI of the two or more sTTIs.

[0012] Another wireless communication device is described. The device may include a processor, a memory in electronic communication with the processor, and instructions stored in the memory. The instructions may be operable, when executed by the processor, to cause the device to identify a set of sTTIs for uplink transmission of a first wireless service, the set of sTTIs being within a subframe time boundary of a subframe of a second wireless service, identify two or more sTTIs in the set of sTTIs for transmitting an SRS transmission within the subframe time boundary, and send one or more SRS transmissions in at least one sTTI of the two or more sTTIs.

[0013] A non-transitory computer-readable medium for wireless communications is described. The non-transitory computer-readable medium may include instructions operable to cause a processor to identify a set of sTTIs for uplink transmissions of a first wireless service, the set of sTTIs being within a subframe time boundary of a subframe of a second wireless service, identify two or more sTTIs in the set of sTTIs for transmitting SRS transmissions within the subframe time boundary, and send one or more SRS transmissions in at least one sTTI of the two or more sTTIs.

[0014] In some examples of the methods, apparatus, and non-transitory computer-readable media described above, the number of SRS transmissions within the subframe time boundary is configurable by a base station.

[0015] Some examples of the methods, apparatus, and non-transitory computer-readable media described above may also include processing, features, units, or instructions for identifying a first subset of the sTTI sets, each of which spans two OFDM symbols, and a second subset of the sTTI sets, each of which spans three OFDM symbols. Some examples of the methods, apparatus, and non-transitory computer-readable media described above may also include processing, features, units, or instructions for configuring the two or more sTTIs of the second subset for SRS transmission.

[0016] In some examples of the methods, apparatus, and non-transitory computer-readable media described above, identifying the second subset includes identifying a first three-symbol sTTI within the subframe time boundary as an initial sTTI for the first time slot; identifying a second three-symbol sTTI within the subframe time boundary as a final sTTI for the second time slot; and identifying a first SRS symbol in the first three-symbol sTTI for a first SRS transmission and a second SRS symbol in the second three-symbol sTTI for a second SRS transmission, wherein the second SRS symbol of the first subframe is adjacent to the first SRS symbol of a subsequent subframe. Some examples of the methods, apparatus, and non-transitory computer-readable media described above may also include a process, feature, unit, or instruction for selecting a first frequency band for the first SRS transmission. Some examples of the methods, apparatus, and non-transitory computer-readable media described above may also include a process, feature, unit, or instruction for selecting a second frequency band different from the first frequency band for the second SRS transmission, wherein the first frequency band and the second frequency band may be selected to provide frequency diversity between the first SRS transmission and the second SRS transmission. In some examples of the methods, apparatus, and non-transitory computer-readable media described above, the positions of the first SRS symbol and the second SRS symbol are selected to provide a reduced transition time for a change in one or more of uplink transmit power or resource block allocation associated with the first SRS transmission and the second SRS transmission.

[0017] In some examples of the methods, apparatus, and non-transitory computer-readable media described above, identifying the second subset includes identifying a final sTTI in each of the first time slot and the second time slot within the subframe time boundary as a three-symbol sTTI. In some examples of the methods, apparatus, and non-transitory computer-readable media described above, an SRS symbol position in each sTTI of the second subset may be selected to provide time diversity between subsequent SRS transmissions, and wherein a frequency band of the subsequent SRS transmissions may be selected to provide frequency diversity between the subsequent SRS transmissions.

[0018] Some examples of the methods, apparatus, and non-transitory computer-readable media described above may also include processing, features, units, or instructions for selecting the SRS symbol position in the first time slot as the initial symbol or the last symbol of the associated three-symbol sTTI. Some examples of the methods, apparatus, and non-transitory computer-readable media described above may also include processing, features, units, or instructions for selecting the SRS symbol position in the second time slot as the last symbol of the associated three-symbol sTTI.

[0019] Some examples of the methods, apparatus, and non-transitory computer-readable media described above may also include processing, features, units, or instructions for identifying a subset of the sTTI set that each spans two OFDM symbols. Some examples of the methods, apparatus, and non-transitory computer-readable media described above may also include processing, features, units, or instructions for configuring two or more sTTIs of the subset for use in the SRS transmission. In some examples of the methods, apparatus, and non-transitory computer-readable media described above, two or more two-symbol sTTIs in each of the first time slot and the second time slot within the subframe time boundary are configured for SRS transmission. In some examples of the methods, apparatus, and non-transitory computer-readable media described above, one or both of the OFDM symbols in the two or more sTTIs may be configured for SRS transmission.

[0020] Some examples of the methods, apparatus, and non-periodic computer-readable media described above may also include processing, features, units, or instructions for receiving a non-periodic configuration in an uplink grant indicating resources for the one or more SRS transmissions in at least one of the two or more sTTIs. Some examples of the methods, apparatus, and non-periodic computer-readable media described above may also include processing, features, units, or instructions for receiving a downlink grant indicating an uplink control channel transmission to be sent. Some examples of the methods, apparatus, and non-periodic computer-readable media described above may also include processing, features, units, or instructions for determining the one or more SRS transmissions to be sent based at least in part on the downlink grant.

[0021] In some examples of the methods, apparatus, and non-transitory computer-readable media described above, the one or more SRS transmissions may be used as fill in one or more sTTIs that otherwise do not contain uplink transmissions.

[0022] Some examples of the methods, apparatus, and non-transitory computer-readable media described above may also include processing, features, units, or instructions for receiving configuration information indicating resources for periodic SRS transmission. In some examples of the methods, apparatus, and non-transitory computer-readable media described above, the configuration information includes an indication of a cell-specific sTTI and a UE-specific sTTI to be used for SRS transmission, and wherein some examples of the methods, apparatus, and non-transitory computer-readable media described above may also include processing, features, units, or instructions for identifying the first sTTI to be used for SRS transmission when the first sTTI corresponds to both a cell-specific sTTI and a UE-specific sTTI.

[0023] Some examples of the methods, apparatus, and non-transitory computer-readable media described above may also include a process, feature, unit, or instruction for identifying a first bandwidth for the one or more SRS transmissions based at least in part on at least one of a channel bandwidth or an sTTI length for an uplink transmission. In some examples of the methods, apparatus, and non-transitory computer-readable media described above, the first bandwidth for the first SRS transmission may be increased relative to a second bandwidth for one or more other SRS transmissions associated with the second wireless service.

[0024] Some examples of the methods, apparatus, and non-transitory computer-readable media described above may also include a process, feature, unit, or instruction for multiplexing a DMRS with a first SRS in a first symbol configured for both DMRS and SRS transmission. In some examples of the methods, apparatus, and non-transitory computer-readable media described above, the multiplexing includes sending the DMRS in a first interlace of the first symbol, and sending the first SRS in a second interlace of the first symbol. In some examples of the methods, apparatus, and non-transitory computer-readable media described above, the multiplexing includes sending the DMRS in a first interlace of the first symbol using a first cyclic shift, and sending the first SRS in the first interlace of the first symbol using a second cyclic shift.

[0025] In some examples of the methods, apparatus, and non-transitory computer-readable media described above, the multiplexing includes sending the DMRS using a first cyclic shift and sending the first SRS using a second cyclic shift. In some examples of the methods, apparatus, and non-transitory computer-readable media described above, the multiplexing includes sending the DMRS using a first set of antenna ports and sending the first SRS using a second set of antenna ports that may be different from the first set of antenna ports.

[0026] A wireless communication method is described. The method may include identifying a set of sTTIs for uplink transmission of a first wireless service, the set of sTTIs being within a subframe time boundary of a subframe of a second wireless service; identifying two or more sTTIs in the set of sTTIs for transmitting SRS transmissions within the subframe time boundary; and configuring a UE to send one or more SRS transmissions using at least one sTTI in the two or more sTTIs.

[0027] A wireless communication apparatus is described. The method may include means for identifying a set of sTTIs for uplink transmission of a first wireless service, the set of sTTIs being within a subframe time boundary of a subframe of a second wireless service, means for identifying two or more sTTIs in the set of sTTIs for transmitting an SRS transmission within the subframe time boundary, and means for configuring a UE to send one or more SRS transmissions using at least one sTTI of the two or more sTTIs.

[0028] Another wireless communication device is described. The device may include a processor, a memory in electronic communication with the processor, and instructions stored in the memory. The instructions may be operable, when executed by the processor, to cause the device to identify a set of sTTIs for uplink transmission of a first wireless service, the set of sTTIs being within a subframe time boundary of a subframe of a second wireless service; identify two or more sTTIs in the set of sTTIs for transmitting SRS transmissions within the subframe time boundary; and configure a UE to send one or more SRS transmissions using at least one sTTI of the two or more sTTIs.

[0029] A non-transitory computer-readable medium for wireless communications is described. The non-transitory computer-readable medium may include instructions operable to cause a processor to identify a set of sTTIs for uplink transmission of a first wireless service, the set of sTTIs being within a subframe time boundary of a subframe of a second wireless service; identify two or more sTTIs in the set of sTTIs for transmitting SRS transmissions within the subframe time boundary; and configure a UE to send one or more SRS transmissions using at least one sTTI of the two or more sTTIs.

[0030] Some examples of the methods, apparatus, and non-transitory computer-readable media described above may also include processing, features, units, or instructions for configuring a first subset of the sTTI sets, each of which spans two OFDM symbols, and a second subset of the sTTI sets, each of which spans three OFDM symbols. Some examples of the methods, apparatus, and non-transitory computer-readable media described above may also include processing, features, units, or instructions for configuring the two or more sTTIs of the second subset for SRS transmission.

[0031] In some examples of the methods, apparatus, and non-transitory computer-readable media described above, configuring the second subset includes configuring a first three-symbol sTTI as an initial sTTI for a first time slot within the subframe time boundary, configuring a second three-symbol sTTI as a last sTTI for a second time slot within the subframe time boundary, and configuring a first SRS symbol in the first three-symbol sTTI for a first SRS transmission, and configuring a second SRS symbol in the second three-symbol sTTI for a second SRS transmission, wherein the second symbol of the first subframe may be adjacent to the first symbol of a subsequent subframe. In some examples of the methods, apparatus, and non-transitory computer-readable media described above, the positions of the first SRS symbol and the second SRS symbol are selected to provide a reduced transition time for a change in one or more of uplink transmit power or resource block allocation associated with the first SRS transmission and the second SRS transmission.

[0032] In some examples of the methods, apparatus, and non-transitory computer-readable media described above, configuring the second subset includes configuring the last sTTI in each of the first time slot and the second time slot within the subframe time boundary as a three-symbol sTTI.

[0033] Some examples of the methods, apparatus, and non-transitory computer-readable media described above may also include processing, features, units, or instructions for identifying a subset of the set of sTTIs that each spans two OFDM symbols. Some examples of the methods, apparatus, and non-transitory computer-readable media described above may also include processing, features, units, or instructions for configuring two or more sTTIs of the subset for use in the one or more SRS transmissions. In some examples of the methods, apparatus, and non-transitory computer-readable media described above, one or both of the OFDM symbols in the two or more sTTIs may be configured for SRS transmission.

[0034] Some examples of the methods, apparatus, and non-periodic computer-readable media described above may also include processing, characteristics, units, or instructions for sending a non-periodic configuration to the UE in an uplink grant indicating resources for the one or more SRS transmissions. Some examples of the methods, apparatus, and non-periodic computer-readable media described above may also include processing, characteristics, units, or instructions for sending a downlink grant to the UE indicating an uplink control channel transmission to be sent and the one or more SRS transmissions to be sent. In some examples of the methods, apparatus, and non-periodic computer-readable media described above, determining that the one or more SRS transmissions are to be sent may be based at least in part on an indication in the downlink grant that data and DMRS are to be sent in two symbols of a three-symbol sTTI.

[0035] Some examples of the methods, apparatus, and non-transitory computer-readable media described above may also include processing, features, units, or instructions for sending configuration information indicating resources for periodic SRS transmission. In some examples of the methods, apparatus, and non-transitory computer-readable media described above, the configuration information includes an indication of a cell-specific sTTI and a UE-specific sTTI to be used for SRS transmission, and identifies a first sTTI for SRS transmission when the first sTTI corresponds to both a cell-specific sTTI and a UE-specific sTTI.

[0036] Some examples of the methods, apparatus, and non-transitory computer-readable media described above may also include processing, features, units, or instructions for identifying a first bandwidth information of a first SRS transmission of the one or more SRS transmissions based at least in part on one or more of a channel bandwidth or sTTI length of an uplink transmission.

[0037] Some examples of the methods, apparatuses, and non-transitory computer-readable media described above may also include processing, features, units, or instructions for configuring the UE to multiplex the DMRS with the first SRS transmission in the first symbol. Some examples of the methods, apparatuses, and non-transitory computer-readable media described above may also include processing, features, units, or instructions for receiving the DMRS in the first interlace of the first symbol, and receiving the first SRS transmission in the second interlace of the first symbol. Some examples of the methods, apparatuses, and non-transitory computer-readable media described above may also include processing, features, units, or instructions for receiving the DMRS in the first interlace of the first symbol using a first cyclic shift, and receiving the first SRS transmission in the first interlace of the first symbol using a second cyclic shift. Some examples of the methods, apparatuses, and non-transitory computer-readable media described above may also include processing, features, units, or instructions for receiving the DMRS using a first cyclic shift, and receiving the first SRS transmission using a second cyclic shift. Some examples of the methods, apparatuses, and non-transitory computer-readable media described above may also include processing, features, units, or instructions for receiving the DMRS using a first antenna port set, and receiving the first SRS transmission using a second antenna port set that may be different from the first antenna port set. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 An example of a wireless communication system supporting SRS transmission in low-latency wireless transmission according to aspects of the present disclosure is depicted.

[0039] Figure 2 An example of a wireless communication system supporting SRS transmission in low-latency wireless transmission according to aspects of the present disclosure is depicted.

[0040] Figure 3 An example of slot-aligned sTTI resources for supporting SRS transmission in low-latency wireless transmissions according to aspects of the present disclosure is depicted.

[0041] Figure 4 Depicted are examples of uplink resources in a subframe that can support SRS transmission in low-latency wireless transmissions according to aspects of the present disclosure.

[0042] Figure 5 Another example of uplink resources in a subframe that can support SRS transmission in low-latency wireless transmission according to aspects of the present disclosure is depicted.

[0043] Figure 6 Depicted are examples of frequency bands in subframes that may be selected for supporting SRS transmissions in low-latency wireless transmissions in accordance with aspects of the present disclosure.

[0044] Figure 7 Depicted are examples of radio resources and transition times for SRS transmission in low-delay wireless transmission according to aspects of the present disclosure.

[0045] Figure 8 Depicted is another example of radio resources and transition times for SRS transmission in low-delay wireless transmission according to aspects of the present disclosure.

[0046] Fig. 9 Depicted are examples of frequency resources that can support SRS transmission in low-latency wireless transmissions according to aspects of the present disclosure.

[0047] Fig.10 An example of reference signal multiplexing supporting SRS transmission in low-latency wireless transmission is depicted according to aspects of the present disclosure.

[0048] Fig.11 An example of a process flow to support SRS transmission in low-latency wireless transmission according to aspects of the present disclosure is depicted.

[0049] Figures 12 to 14 A block diagram of an apparatus supporting SRS transmission in low-delay wireless transmission according to aspects of the present disclosure is shown.

[0050] Fig.15 A block diagram of a system including a UE supporting SRS transmission in low-latency wireless transmissions according to aspects of the present disclosure is depicted.

[0051] Figures 16 to 18 A block diagram of an apparatus supporting SRS transmission in low-delay wireless transmission according to aspects of the present disclosure is shown.

[0052] Fig.19 A block diagram of a system including a base station supporting SRS transmission in low-latency wireless transmissions according to aspects of the present disclosure is depicted.

[0053] Figures 20 to 36 Methods of supporting SRS transmission in low-latency wireless transmissions according to aspects of the present disclosure are described. DETAILED DESCRIPTION

[0054] The improved methods, systems, devices or apparatuses of various examples can be used to support the transmission of sounding reference signals (SRS) for shortened transmission time interval (sTTI) communications in low-delay wireless communication systems. Resources allocated to low-delay communications can be used for uplink and downlink communications using sTTIs with reduced TTI lengths relative to communications that may be relatively delay-insensitive (such as enhanced mobile broadband (eMBB) transmissions that can use 1ms TTI durations). Communications using sTTIs can use sTTI durations corresponding to one slot of a radio subframe in some cases, or sTTI durations corresponding to two or three orthogonal frequency division multiplexing (OFDM) symbols. In some cases, sTTIs can be configured to have boundaries within or aligned with boundaries of one slot of a 1ms TTI. In some examples, the sTTI can span two or three OFDM symbols, and each slot can have three sTTIs. In this way, all seven symbols in one slot of a conventional cyclic prefix can be used, and system resources can be more efficiently utilized relative to the case where three two-symbol sTTIs are included in one seven-symbol slot.

[0055] Various techniques disclosed in this application can provide support for identifying uplink resources for sTTI transmission. A portion of the uplink resources can be used for reference signal transmission, such as SRS transmission.

[0056] In some examples, resources for several sTTIs can be aligned in a slot in a subframe boundary including the several sTTIs, and two or more sTTIs can be configured for SRS transmission. An sTTI can have a length corresponding to the length of a slot in some examples. In other examples, multiple sTTIs can be located in each slot, each sTTI having a length of two or three OFDM symbols.

[0057] In some cases, one OFDM symbol of each time slot may be identified for SRS transmission. In some examples, each time slot may include two 2-symbol sTTIs and one 3-symbol sTTI, and the OFDM symbol of each 3-symbol sTTI may be selected for SRS transmission. In some examples, two or more symbols from two or more 2-symbol sTTIs may be selected for SRS transmission. SRS transmission may be configured as aperiodic SRS transmission or periodic SRS transmission in some examples. In some cases, the bandwidth for SRS transmission may be selected to provide frequency diversity for channel estimation. In addition, in some cases, SRS transmission may be multiplexed with other transmissions, such as demodulation reference signal (DMRS) transmission or SRS transmission from other transmitters.

[0058] Low-latency communications using sTTI can be used in systems that support multiple different services, such as data communications. Different services can be selected depending on the characteristics of the communication. For example, communications that require low latency and high reliability, sometimes referred to as mission-critical (MiCr) communications, can be served by low-latency services (e.g., URLLC services) using sTTI. Accordingly, communications that are more tolerant to delays can be served by services that provide relatively higher throughput with slightly higher delays, such as mobile broadband services (e.g., eMBB services) using 1ms TTI. In other examples, communications can be performed with UEs incorporated into other devices (e.g., meters, vehicles, appliances, machinery, etc.), and machine type communication (MTC) services (e.g., large MTC (mMTC)) can be used for these communications. In some cases, different services (e.g., eMBB, URLLC, mMTC) can have different TTIs, different subcarrier (or frequency modulation) intervals, and different cyclic prefixes.

[0059] The present disclosure describes various techniques with reference to next generation networks (e.g., 5G or NR networks) that are designed to support features such as high bandwidth operation, more dynamic subframe / time slot types, and self-contained subframe / time slot types (wherein hybrid automatic re-request (HARQ) feedback for a subframe / time slot may be sent before the end of the subframe / time slot). However, these techniques may be used in any system that may send TTIs of varying lengths in a wireless communication system.

[0060] Aspects of the present disclosure are initially described in the context of a wireless communication system. Various examples of SRS configurations for different sTTI resources are then discussed. Aspects of the present disclosure are also shown and described with reference to apparatus schematics, system schematics, and flow charts for reference signal patterns and pilot sharing for shortened transmission time interval wireless communications.

[0061] Figure 1 An example of a wireless communication system 100 according to various aspects of the present disclosure is depicted. The wireless communication system 100 includes a base station 105, a UE 115, and a core network 130. In some examples, the wireless communication system 100 can be an LTE (or Advanced LTE) network, or a New Radio (NR) network. In some cases, the wireless communication system 100 can support enhanced broadband communications, ultra-reliable (i.e., mission-critical) communications, low-latency communications, and communications using low-overhead and low-complexity devices. SRS transmissions associated with low-latency communications can be sent from a UE 115 of the wireless communication system 100 according to the techniques discussed in this application.

[0062] The base station 105 can wirelessly communicate with the UE 115 through one or more base station antennas. Each base station 105 can provide communication coverage for the corresponding geographic coverage area 110. The communication link 125 shown in the wireless communication system 100 may include an uplink (UL) transmission from the UE 115 to the base station 105, or a downlink (DL) transmission from the base station 105 to the UE 115. Control information and data are multiplexed on the uplink channel or the downlink according to various technologies. Control information and data can be, for example, multiplexed on the downlink channel using time division multiplexing (TDM) technology, frequency division multiplexing (FDM) technology, or hybrid TDM-FDM technology. In some examples, the control information sent within the TTI of the downlink channel can be distributed between different control areas in a cascaded manner (e.g., between a common control area and one or more UE-specific control areas).

[0063] UE 115 can be dispersed throughout the wireless communication system 100, and each UE 115 can be fixed or mobile. UE 115 can also be referred to as a mobile station, a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communication device, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handset, a user agent, a mobile client, a client, or some other applicable term. UE 115 can also be a cellular phone, a personal digital assistant (PDA), a wireless modem, a wireless communication device, a handheld device, a tablet computer, a laptop computer, a cordless phone, a personal electronic device, a handheld device, a personal computer, a wireless local loop (WLL) station, an Internet of Things (IoT) device, an Internet of Everything (IoE) device, an IoE device, a machine type communication (MTC) device, an apparatus, a car, a drone, etc.

[0064] In some cases, UE 115 may also be able to communicate directly with other UEs (e.g., using peer-to-peer (P2P) or device-to-device (D2D) protocols). Some UE 115, such as MTC or IoT devices, may be low-cost or low-complexity devices and may provide automated communication between machines, i.e., machine-to-machine (M2M) communication. M2M or MTC may refer to data communication technology that allows devices to communicate with each other or with a base station without human intervention. Examples of applications of MTC devices include smart meters, inventory monitoring, water level monitoring, equipment monitoring, medical health monitoring, wildlife monitoring, meteorological and geological event monitoring, fleet management and tracking, remote security sensing, physical access control, and transaction-based service billing.

[0065] In some cases, MTC devices may operate using half-duplex (one-way) communications at reduced peak rates. MTC devices may also be configured to enter a power-saving "deep sleep" mode when not engaged in active communications. In some cases, MTC or IoT devices may be assigned to support mission-critical functions, and the wireless communication system may be configured to provide ultra-reliable and low-latency communications for those functions.

[0066] The base stations 105 may communicate with the core network 130 and with each other. For example, the base stations 105 may interact with the core network 130 via a backhaul link 132 (e.g., S1, etc.). The base stations 105 may communicate with each other directly or indirectly (e.g., via the core network 130) over a backhaul link 134 (e.g., X2, etc.). The base stations 105 may perform radio configuration and scheduling for communications with the UE 115, or may operate under the control of a base station controller (not shown). In some examples, the base stations 105 may be macro cells, small cells, hot spots, and the like. The base stations 105 may be examples of LTE eNBs, eLTE eNBs, NR gNBs, NR Node Bs, NR access nodes, and may include access node controllers (ANCs).

[0067] The base stations 105 may be connected to the core network 130 via a backhaul link 132 (e.g., S1, S2, NG-1, NG-2, NG-3, NG-C, NG-U, etc.) and may perform wireless configuration and scheduling for communications with UEs 115 in associated coverage areas 110. In various examples, the network devices 105-b may communicate with each other directly or indirectly (e.g., via the core network 130) over a backhaul link 134 (e.g., X1, X2, Xn, etc.), which may be a wired or wireless communication link. Each base station 105 may also communicate with a number of UEs 115 via a number of other network devices, which may be examples of a transmission reception point (TRP), a distributed unit (DU), a radio head (RH), a remote radio head (RRH), or a smart radio head.

[0068] The wireless communication system 100 may support operation on multiple cells or carriers, a feature that may be referred to as carrier aggregation (CA) or multi-carrier operation. A carrier may also be referred to as a component carrier (CC), layer, channel, etc. The terms "carrier," "component carrier," "cell," and "channel" may be used interchangeably in this application. A UE 115 may be configured with multiple downlink CCs and one or more uplink CCs for carrier aggregation. Carrier aggregation may be used with FDD and TDD component carriers.

[0069] In some cases, the wireless communication system 100 may use an enhanced component carrier (eCC). An eCC may be characterized by one or more characteristics, including: wider bandwidth, shorter symbol duration, shorter transmission time interval (TTI). In some cases, an eCC may be associated with a carrier aggregation configuration or a bidirectional connection configuration (for example, when multiple serving cells have suboptimal or non-ideal backhaul links). An eCC may also be configured for use in an unlicensed spectrum or a shared spectrum (where more than one operator is allowed to use the spectrum). In some cases, an eCC may use a symbol duration different from that of other CCs, which may include the use of a symbol duration that is reduced compared to the symbol duration of other CCs. A shorter symbol duration may be associated with an increased subcarrier spacing. A TTI in an eCC may consist of one or more symbols. In some cases, the TTI duration (that is, the number of symbols in a TTI) may be variable. In some cases, an eCC may use a symbol duration that is different from that of other CCs, which may include the use of a symbol duration that is reduced compared to the symbol duration of other CCs. A shorter symbol duration is associated with an increased subcarrier spacing. A device using eCC, such as UE 115 or base station 105, can transmit wideband signals (e.g., 20, 40, 60, 80 MHz, etc.) with a reduced symbol duration (e.g., 16.67 microseconds). A TTI in an eCC can consist of one or more covers. In some cases, the TTI duration (i.e., the number of symbols in a TTI) is variable. A 5G or NR carrier can be considered an eCC.

[0070] In some cases, the wireless system 100 can use both licensed and unlicensed wireless spectrum bands. For example, the wireless system 100 can use LTE license assisted access (LTE-LAA) or LTE unlicensed (LTE-U) wireless access technology or NR technology in an unlicensed band (such as the 5Ghz industrial, scientific and medical (ISM) band). When operating in an unlicensed radio spectrum band, wireless devices such as base stations 105 and UE 115 can use a listen-before-talk (LBT) procedure to ensure that the channel is idle before sending data. In some cases, operations in unlicensed bands can be based on a carrier aggregation (CA) configuration in conjunction with a component carrier (CC) operating in a licensed band. Operations in an unlicensed spectrum can include downlink transmissions, downlink transmissions, or both. Duplexing in an unlicensed spectrum can be based on frequency division duplexing (FDD), time division duplexing (TDD), or a combination of the two.

[0071] The time interval in LTE or NR can be expressed in terms of a basic time unit (which can be T s=1 / 30,720,000 seconds of sampling period). The time resources in LTE / LTE-A can be expressed in terms of the length of 10ms (T f =307200T s ) radio frames, which can be identified by a system frame number (SFN) ranging from 0 to 1023. Each frame can include ten 1 ms subframes numbered from 0 to 9. A subframe can be further divided into two 0.5 ms time slots, each of which contains 6 or 7 modulation symbol periods (depending on the length of the cyclic prefix pre-added before each symbol). In addition to the cyclic prefix, each symbol contains 2048 sampling periods. In some cases, the subframe can be the smallest scheduling unit, also known as TTI. In other cases, a TTI can be shorter than a subframe or can be dynamically selected (for example, in an sTTI burst or in a selected component carrier using sTTI). The various examples discussed in the present application provide techniques for shortened TTIs, which can provide SRS resources that can appear in two or more sTTIs in a subframe and can be used by the base station 105 to estimate the uplink channel quality associated with the UE 115 on a bandwidth that can be wider than the bandwidth used for uplink data transmission from the UE 115. In some cases, one or more OFDM symbols in the sTTI of each time slot can be configured for SRS transmission.

[0072] Figure 2 An example of a wireless communication system 200 for transmission of a sounding reference signal in low-latency wireless transmission is depicted. The wireless communication system 200 includes a base station 105-a and a UE 115-a, which may be as described above with reference to Figure 1 Examples of aspects of UE 115 are described. Figure 2 In the example shown, the wireless communication system 200 can operate according to a radio access technology (RAT) such as 5G or NR RAT, but the techniques described in this application can be applied to any RAT and systems that can use two or more different RATs concurrently.

[0073] The base station 105-a can communicate with the UE 115-a on the carrier 205. In some examples, the base station 105-a can allocate resources for communicating with the UE on the carrier 205. For example, the base station 105-a can allocate subframes 210 for communicating with the UE 115-a, and one or more subframes 210 can correspond to a traditional LTE TTI with a TTI length of 1 ms. In this example, the subframes 210 may include a first subframe 210-a, a second subframe 210-b, and a third subframe 210-c. Each subframe 210 may include two time slots, wherein each time slot may have seven symbols for a conventional cyclic prefix. In this example, a first time slot (time slot 0) 220 and a second time slot (time slot 1) 225 may be included in the first subframe 210-a.

[0074] As indicated above, in the uplink of the low-latency system, different sTTI lengths may be used for transmissions on the carrier 205. For example, two-symbol sTTI, three-symbol sTTI, and 1-slot sTTI durations may be supported for physical uplink control channel (PUCCH) and physical uplink shared channel (PUSCH) transmissions (or shortened PUCCH (sPUCCH) and shortened PUSCH (sPUSCH) transmissions). Thus, in a first slot 220 or a second slot 225, there may be multiple sTTIs, such as a first sTTI (TTI-0) 230, a second sTTI (TTI-1) 235, and a third sTTI (TTI-2) 240, each of which may have two or three OFDM symbol durations.

[0075] When using two-symbol or three-symbol sTTIs, in some cases, it is desirable to have a fixed sTTI structure in which the sTTI boundaries are located within or aligned with the slot boundaries, such as the boundaries of the first slot 220 or the second slot 225, which may be referred to as slot-aligned sTTIs. As discussed above, when using a conventional CP, seven symbols are included in each slot 220-225, and thus each slot may include three sTTIs for slot-aligned sTTIs. As the TTI length becomes shorter, it may not always be possible to reuse the traditional SRS resources for SRS transmissions for sTTI transmissions because a particular sTTI may not include traditional SRS resources. More specifically, in conventional LTE, SRS may be sent on the last OFDM symbol in a valid SRS subframe and may be used for uplink frequency selective scheduling and / or uplink timing estimation (especially when there is no physical uplink shared channel (PUSCH) or physical uplink control channel (PUCCH) transmission for a period of time).

[0076] SRS transmission can be carried out on frequency resources that are the same, overlapping or different from those of PUSCH transmission from UE 115-a. In addition, different types of SRS are supported. More specifically, type 0 SRS can be triggered by radio resource control (RRC) signaling, which can include a single SRS or a periodic SRS with a periodic range of 2ms to 320ms. Traditional SRS types also include type 1 SRS, which can be configured by RRC, but triggered by DL / UL DCI, and different SRS configuration sets are defined by the higher layer and can include, for example, SRS bandwidth, frequency domain position, transmission comb index, cyclic shift (CS), etc. From the perspective of frequency domain resource selection, SRS transmission can be classified as a broadband SRS that occupies the entire bandwidth of interest (not necessarily the entire available bandwidth), or a narrowband SRS that can be more suitable for users in poor coverage and allows UE 115 to hop between SRS transmissions. The SRS resources can be configured by the base station 105-a by providing a cell-specific SRS configuration that defines a subframe that can contain SRS transmissions and a set of SRS bandwidths available in the cell. The base station 105-a can also provide a UE-specific SRS configuration that defines time domain and frequency domain resources. If the UE-specific SRS subframe of a UE 115-a in such a deployment is consistent with the cell-specific SRS subframe, the UE can send SRS. The UE 115-a can also suppress transmissions in SRS resources that are not in the cell-specific SRS subframe to avoid interference with SRS transmissions of other UEs.

[0077] When using sTTI operation, the traditional SRS configuration may not provide enough SRS opportunities for UE 115-a, because there is at most one SRS transmission opportunity for each 1ms subframe. Under this sTTI operation, given better time allocation (smaller sTTI length), various aspects of the present disclosure provide multiple SRS transmission opportunities in a subframe. These SRS transmissions can be advantageous, for example, because they provide uplink link adaptation that can better track channel changes over time in systems based on both FDD and TDD, which can be applicable to high-speed scenarios that rely on URLLC services. Multiple SRS transmissions per subframe may also be advantageous in situations where UE 115-a is in poor coverage, and can be configured to send SRS over a relatively narrow frequency bandwidth using frequency hopping across multiple SRS opportunities by allowing faster channel estimation (for example, a specific frequency band can be covered faster with additional SRS transmission opportunities per subframe). In addition, the faster channel estimation that can be provided in part by the additional SRS transmission can help increase both network capacity and UE 115-a perceived throughput.

[0078] Figure 3An example of a time slot aligned sTTI resource 300 for supporting SRS transmission in low latency wireless transmission is depicted. The sTTI resource 300 may be used, for example, as described above with respect to Figure 1 and 2 The time slot alignment sTTI mode for low-latency communication between the UE and the base station discussed. The subframe 310 may have resources allocated for uplink transmission. The subframe 310 may include two time slots: a first time slot (time slot 0) 315 corresponding to 1ms or a traditional LTE TTI time slot and a second time slot (time slot 1) 320. Each time slot 315 and 320 may include a time slot alignment sTTI allocated to low-latency communication, for example according to a first time slot alignment 345 or a second time slot alignment 355. Each time slot 315 and 320 may include three sTTIs, including a first TTI (TTI-0) 325, a second TTI (TTI-1) 330, and a third TTI (TTI-2) 335, and may have frequency resources corresponding to a frequency bandwidth f0 350.

[0079] As can be seen above, in order to ensure that the sTTI does not cross the slot boundary in the 1ms subframe 310, both 2-symbol and 3-symbol sTTIs can be used in slots 315 or slots 320. In the first slot alignment 345, each of the first sTTI 325 and the second sTTI 330 has two OFDM symbols, and the third sTTI 335 can have three OFDM symbols. In the second slot alignment 355, the first sTTI 325 can have three symbols, and each of the second sTTI 330 and the third sTTI 335 has two OFDM symbols. In some examples, a particular subframe 310 can be configured with a pattern based on slot 0 315 with the second slot alignment 355 and slot 1 320 with the first slot alignment 345 (i.e., a [3,2,2,2,2,3] pattern, which may be referred to as pattern 1 in this application). In other examples, the subframe 310 may be configured with a pattern based on slot 0 315 and slot 1 320 with a first slot alignment 345 (i.e., a [2,2,3,2,2,3] pattern, which may be referred to herein as Mode 2). Of course, other patterns of 2-symbol and 3-symbol sTTIs in slots, as well as different patterns of slots in a subframe may also be used, and the examples provided herein are provided for purposes of illustration and discussion, with the understanding that similar techniques may be used for other patterns. Figure 4 Depicted are resources in a subframe with different sTTI modes that can be used for SRS transmission.

[0080] Figure 4 An example of uplink resources 400 in a subframe that can support SRS transmission in low-latency wireless transmission is depicted. The uplink resources 400 can be used, for example, as described above with respect to Figures 1 to 3 The slot-aligned sTTI mode for low-latency communication between the UE and the base station discussed. In this example, the first subframe 405 can be configured with mode 1, and there can be a first sTTI (sTTI-0) 415 with three OFDM symbols, a second to fifth sTTI (sTTI-1 to sTTI-4) 420-435 each with two OFDM symbols, and a sixth sTTI (sTTI-5) 440 that can have three OFDM symbols. Also in this example, the second subframe 410 can be configured with mode 2, and there can be a first sTTI (sTTI-6) 450 and a second sTTI (sTTI-7) 455 with two OFDM symbols, a third sTTI (sTTI-8) 460 with three OFDM symbols, followed by a fourth sTTI (sTTI-9) 465 and a fifth sTTI (sTTI-10) 470 with two OFDM symbols, and a sixth sTTI (sTTI-11) 475 with three OFDM symbols.

[0081] In some examples, a 3-symbol sTTI can be configured with resources for SRS 445 transmissions. In some examples, a first subframe 405 can have SRS resources 445-a present in sTTI-0 415, SRS resources 445-b present in sTTI-5 440. A second subframe 410 in these examples can have SRS resources 445-c present in sTTI-8 460, and SRS resources 445-d present in sTTI-11 475. In the case of uplink transmissions in mode 1 using this first subframe 405, consecutive subframes will have adjacent 3-symbol sTTIs, and thus the time diversity gain from multiple SRS 445 transmissions in a subframe may be small. In some examples, as will be discussed in more detail below, SRS 445 transmissions from adjacent sTTIs can be sent on different frequency bands for frequency diversity, which can allow the entire available bandwidth to be covered relatively quickly. The SRS 445 transmissions in these adjacent sTTIs may in other examples be sent on the same frequency band, which may allow some time diversity and may be used, for example, in situations where the mobile device is moving at very high speeds relative to the base station.

[0082] In the case of uplink transmission of mode 2 using the second subframe 410, two 3-symbol sTTIs, namely sTTI-8 460 and sTTI-11 475, are evenly distributed in the second subframe 410. Therefore, in some examples, SRS 445-c and SRS 445-d can be sent using different frequency resources, and in addition, it is possible to obtain some channel time diversity when estimating the channel of a specific frequency band.

[0083] In each 3-symbol sTTI, resources may be reserved for SRS transmission in one symbol, such as the first or last symbol of the 3-symbol sTTI, thereby providing a pattern of [X,X,SRS] or [SRS,X,X], where X is data / DMRS / empty. In these cases, the remaining two symbols of each 3-symbol sTTI may be used for uplink data and / or DMRS transmission (or no transmission may be sent if there is an empty symbol). As discussed above, subframe pattern 1 ([3,2,2,2,2,3]) may be used in some cases, and in these cases, the SRS pattern in the 3-symbol sTTI may be [X,X,SRS] on the last 3-symbol sTTI of a subframe, which may be consistent with a traditional SRS symbol. For the initial 2-symbol sTTI of a subframe, for example, a pattern of [SRS,X,X] or [X,X,SRS] may be used. In some cases, the initial 3-symbol sTTI is configured with the pattern [SRS, X, X], which can provide lower demodulation loss due to power transition time, as discussed in more detail below. If a subframe is configured with mode 2 ([2,2,3,2,2,3]), the configuration of the last 3-symbol sTTI can be the same as discussed above to provide consistency with traditional SRS symbols, and the first 3-symbol sTTI of the subframe can be configured with, for example, [SRS, X, X] or [X, X, SRS].

[0084] In some examples, the UE may be configured to send aperiodic SRS. In these cases, the SRS transmission / position may be indicated in the downlink control information (DCI) including the UL grant when there is data or DMRS to send. In some examples, the SRS transmission / position may also be indicated in a DL grant, which may indicate that the UE is to send a sPUCCH transmission. For example, the [DMRS, Data, SRS] pattern may be used on the 3-symbol sTTI, where [DMRS, Data] is configured in the sPUCCH transmission and the SRS transmission is implicitly indicated without a specific grant. In some cases, the SRS may also be used as a filler, with the accompanying 3-symbol sTTI or 2-symbol sTTI patterns being [Null, Null, SRS], [SRS, Null, Null], [Null, SRS], or [SRS, Null].

[0085] In some examples, the UE may be configured to send periodic SRS. Periodic SRS may be more suitable for scenarios where different frequency bands are allocated to 1ms TTI and sTTI operations, in which case SRS transmissions outside the last symbol of a subframe will be less likely to interfere with data transmissions of other UEs due to transmissions on different frequencies. Therefore, one symbol in each 3-symbol sTTI in these examples may be configured as an SRS symbol, similar to traditional LTE or 1ms TTI operations where the last symbol of a subframe is an SRS symbol and is used by the UE for periodic SRS transmissions. In order to make periodic SRS effective, in some examples the base station may configure certain cell-specific SRS sTTIs that are common to all UEs served by the base station. For each served UE, the base station may configure a UE-specific SRS sTTI. The cell-specific and UE-specific sTTIs may be defined only within cell-specific and UE-specific SRS subframes (associated with traditional LTE services or with 1ms TTI services), or may be defined on different sets of subframes. The UE may send SRS in a configured mode when its UE-specific SRS sTTI matches the cell-specific SRS sTTI. Furthermore, the UE does not send sPUSCH on the SRS symbols defined within the cell-specific SRS sTTI to avoid interference with the SRS transmission.

[0086] Figure 5 Another example of an uplink resource 500 in a subframe that can support SRS transmission in low-delay wireless transmission is depicted. The uplink resource 500 can be used, for example, as described above with respect to Figures 1 to 3 The slot-aligned sTTI mode for low-latency communication between the UE and the base station discussed. In this example, the subframe 505 can be configured with mode 1, and there can be a first sTTI (sTTI-0) 510 with three OFDM symbols, a second to fifth sTTI (sTTI-1 to sTTI-4) 515-530 each with two OFDM symbols, and a sixth sTTI (sTTI-5) 535 that can have three OFDM symbols.

[0087] In some examples, both 3-symbol sTTI and 2-symbol sTTI can be configured with resources for SRS 540 transmissions. In these examples, the 2-symbol sTTI can provide additional SR opportunities, and the frequency resources of the SRS 540 transmissions can be selected to provide frequency hopping that can cover the transmission bandwidth of interest in a relatively short period, and the SRS540 resources of some SRS 540 transmissions can be selected to have the same time-frequency resources with sufficiently large time intervals to provide good time diversity. This frequency diversity and time diversity can be used to estimate the uplink channel quality over the required transmission bandwidth. Figure 5In the examples of , symbols in each sTTI 510-535 to be used for SRS transmission can be selected to provide adjacent symbols with SRS transmissions, which can provide reduced transition times and enhanced demodulation performance for any data transmissions appearing in non-SRS symbols, as will be discussed in more detail below. On a 2-symbol sTTI, different symbols can be configured as [SRS, SRS], [Null, SRS], [SRS, Null], [DMRS, SRS], [SRS, DMRS], [Data, SRS], or [SRS, Data]. The data, SRS, DMRS, null pattern of the 3-symbol sTTI can include any available combination, such as the patterns discussed above. In some cases, since each sTTI in these examples includes at least one SRS transmission, the SRS transmissions can be configured according to a non-periodic configuration, which helps reduce the potential impact on concurrent 1ms transmissions.

[0088] Figure 6 An example of a frequency band in a subframe 600 that may be selected for SRS transmission in a low-delay wireless transmission is depicted. The subframe 600 may be used, for example, as described above with respect to Figure 1 and 2 In the low-latency communication between the UE and the base station discussed. In this example, the subframe 600 can be configured with mode 1 and can have a first frequency band f-0605 and a second frequency band f-1610 that can be used for uplink transmission. The subframe 600 configured with mode 1 can have a first sTTI (sTTI-0) 615 with three OFDM symbols, a second to fifth sTTI (sTTI-1 to sTTI-4) 620-635 each with two OFDM symbols, and a sixth sTTI (sTTI-5) 640 that can have three OFDM symbols.

[0089] As discussed above, in some cases, data transmissions, such as PUSCH or sPUSCH transmissions outside of configured SRS symbols, may be sent using a bandwidth that is less than the available system bandwidth, and the SRS transmissions 645 may be sent at a different bandwidth than other data transmissions. In some cases, the SRS transmissions 645 from a UE may be sent according to a frequency hopping pattern configured at the UE, wherein the SRS transmissions 645 are sent at different frequencies in order to obtain channel quality information at the base station across the bandwidth of interest. Figure 6 In the example of FIG. 1 , a first SRS transmission 645-a may be sent in an initial symbol of an initial sTTI 615 of a subframe 600 using frequency resources of frequency band f-1 610. A second SRS transmission 645-b may be sent in a last symbol of a last sTTI 640 of a subframe 600 using frequency resources of frequency band f-0 605. Figure 6Only two frequency bands are depicted in FIG. 1 , but additional frequency bands may be present in some cases, with frequency resources for SRS transmission being selected, for example, based on a frequency hopping pattern of the SRS.

[0090] Figure 7 An example wireless resource 700 and transition time for SRS transmission in low-delay wireless communication are depicted. The wireless resource 700 can be used, for example, as described above with respect to Figure 1 and 2 In the low-latency communication between the UE and the base station in question. In this example, the last sTTI 705 of subframe n can be a 3-symbol sTTI and include SRS resources 715-a in the last symbol of the sTTI. The first sTTI 710 of subframe n+1 can be a 3-symbol sTTI and also include SRS resources 715-b in the last symbol of the sTTI. Then the second sTTI 720 of subframe n+1 can follow. In this example, regardless of the position of the particular sTTI in the subframe, the SRS resources 715 are in the last symbol of a 3-symbol sTTI. In this case, the transition time associated with the SRS transmission using the SRS resources 715 can occur before and after the SRS transmission, because the SRS transmission itself can be configured to provide SRS on the configured resource blocks (RBs) with stable power, and therefore the transmitting UE uses time before and after the SRS to perform power and / or RB allocation changes between the SRS transmission and the adjacent data or DMRS transmission.

[0091] Therefore, in the case where the SRS 715 symbols are discontinuous, such as in Figure 7In the example, the transition time 725 occurs adjacent to each SRS resource 715, with a first transition time 725-a preceding the first SRS resource 715-a, followed by a second transition time 725-b. Similarly, the non-adjacent SRS resource 715-b is preceded by a transition time 725-c and followed by a transition time 725-d. In some examples, a transition time of 40 μs is allowed for adjusting transmit power and / or RB allocation, while other transition times may be used in other examples. In this case, the last sTTI 705 of subframe n has a transition time of X μs, corresponding to transition time 725-a. However, the first sTTI 710 of subframe n+1 has two transition times, corresponding to transition time 725-b and transition time 725-c, resulting in the first sTTI 710 of subframe n+1 having a transition time of 2X μs. In addition, the second sTTI 720 of subframe n+1 is also affected, having a transition time of X μs, corresponding to transition time 725-d. Therefore, the first sTTI 710 in subframe n+1, or a substantial portion of any first sTTI in a subframe, is subject to a transition time that may have a negative impact on demodulation performance. In some examples, the impact of this transition time is reduced by configuring the SRS symbols to be adjacent if there are SRS transmissions in adjacent sTTIs, as described below. Figure 8 discuss.

[0092] Figure 8 Another example wireless resource 800 and transition time for SRS transmission in low-delay wireless communication is depicted. The wireless resource 800 can be used, for example, as described above with respect to Figure 1 and 2 In the low-latency communication between the UE and the base station in question.

[0093] In this example, the last sTTI 805 of subframe n may be a 3-symbol sTTI and include SRS resources 815-a in the last symbol of the sTTI 805. The first sTTI 810 of subframe n+1 may be a 3-symbol sTTI and include SRS resources 815-b in the initial symbol of the sTTI 810, thereby providing adjacent SRS resources 815 in subframes n and n+1. The second sTTI 820 of subframe n+1 may then immediately follow the sTTI 810. In this example, transition times associated with an SRS transmission using SRS resources 815 may also occur before and after the SRS transmission, but because the SRS resources 815 are in consecutive symbols, the impact on demodulation performance is reduced.

[0094] exist Figure 8In the example of , the last sTTI 805 of Xμs of subframe n corresponds to transition time 825-a, and the first sTTI 810 of 1.5Xμs of subframe n+1 corresponds to transition time 825-c and 1 / 2 of transition time 825-d. Transition time 825-d is shared between sTTI 810 and sTTI 820, which may be due to RB allocation and / or uplink power adjustment between sTTIs. Transition time 825-b may occur between adjacent SRS resources 815 and may be due to, for example, resource block (RB) allocation changes and may be divided between two SRS symbols. Compared to Figure 7 Examples of can result in improved demodulation quality. Thus, in some examples, the location of the SRS symbols can be selected to provide a reduced transition time for changes in one or more of the uplink transmit power or resource block allocations. These techniques can be used for SRS transmission in a 3-symbol sTTI and / or SRS transmission in a 2-symbol sTTI.

[0095] Fig. 9 An example of a frequency resource 900 that can support SRS transmission in low-latency wireless transmission is depicted. The frequency resource 900 can be used, for example, as described above with respect to Figure 1 and 2 In the low-latency communication between the UE and the base station discussed. In this example, the first sTTI (sTTI-0) 905 may include resources occupying the first channel bandwidth (f0) 910 and SRS resources 915-a that may occupy the first SRS bandwidth 920. Fig. 9 The example also includes a second sTTI (sTTI-n) 925, which may include resources occupying a second channel bandwidth (f1) 930 and SRS resources 915-b that may occupy a second SRS bandwidth 935. As discussed above, the bandwidth of the SRS transmission 915 may be different from the bandwidth used for data transmission (e.g., sPUSCH transmission) of the UE.

[0096] In some cases, the bandwidth of the SRS transmission 915 may depend on the sTTI length and / or system bandwidth used for sTTI transmission. In conventional LTE, and in some 1ms TTI services, the minimum SRS bandwidth may be defined as 4RB. In some cases, the minimum SRS bandwidth may be increased for sTTI operation. Since the granularity of resource allocation for sTTI may be greater than the granularity of 1ms TTI resource allocation (e.g., due to the block-based scheme of sTTI resource allocation), and also because sTTI transmission may be supported for UEs with good channel conditions (e.g., UEs closer to the base station), this increase may be supported. Therefore, in some examples, the minimum SRS bandwidth may be the sTTI length and also depend on the system bandwidth. For example, 16 or 20RB SRS resources may be provided for 2-symbol sTTIs on a 10 or 20MHz channel bandwidth, while 4 or 8RB SRS resources may be provided for 2-symbol sTTI transmissions on a smaller bandwidth. For example, 4 or 8RB SRS resources may be provided for time slot sTTIs on 10 or 20MHz. In this way, frequency hopping across multiple SRS opportunities may be accomplished more quickly.

[0097] Fig.10 An example of reference signal multiplexing 1000 for supporting SRS transmission in low-delay wireless transmission is depicted. Reference signal multiplexing 1000 may be used, for example, as described above with respect to Figure 1 and 2 Low latency communication between the UE and the base station discussed. In this example, the first sTTI (sTTI-0) 1005 may include three symbols, and the last symbol 1025 of the sTTI 1005 is configured with both SRS resources and DMRS resources. Fig.10 In the example of , DMRS and SRS can be multiplexed by providing DMRS interleaving 1030 and SRS interleaving 1035 in the last symbol 1025 of the first sTTI 1005. The DMRS interleaving 1030 and SRS interleaving 1035 can thus provide a comb structure, and DMRS and SRS sent from different users can be orthogonal.

[0098] exist Fig.10In the example of , SRS interlace 1035 can cover system bandwidth f0 1015, which is greater than the second bandwidth f1 used for DMRS interlace 1030. In other examples, the two frequencies f0 and f1 can overlap completely. In these examples with completely overlapping reference signal resources, DMRS and SRS can be sent on different combs, or on the same comb with different cyclic prefixes (CS). In other examples, both DMRS and SRS can be sent using a cyclic shift sequence of the base sequence (i.e., making SRS similar to DMRS). In yet other examples, both DMRS and SRS can be sent without any interleaving and using different CS.

[0099] In an example where the frequency bands f0 and f1 allocated by DMRS and SRS do not completely overlap, such as Fig.10 In the example, one is a superset of the other, and DMRS and SRS from different users can be sent through different combs. In other examples, SRS can be sent using the comb-1 structure of LTE, similar to traditional DMRS transmission. In some cases, it is also possible to share a symbol between SRS and DMRS sent from the same UE. For example, when DMRS is not precoded, SRS and DMRS can be sent from the UE through different antenna ports.

[0100] Fig.11 An example of a process flow 1100 for transmitting a sounding reference signal in a low-latency wireless transmission is depicted. The process flow 1100 may include a base station 105-b and a UE 115-b, which may be a reference signal. Figure 1 and 2 Examples of corresponding devices described. The base station 105-b and the UE 115-b may establish a connection 1105 according to an established connection establishment technique for the wireless communication system.

[0101] At block 1110, the base station 105-b may identify that the UL transmission is to use an sTTI. This identification may be made, for example, based on a wireless service that the UE 115-b is capable of supporting and that is to be served to the UE 115-b by the base station 105-b. For example, the UE 115-b may request to establish a URLLC service that may use an sTTI, such as a slotted sTTI or a 2-symbol sTTI. The UE 115-b may also support other services (e.g., eMMB services) or traditional LTE users using a 1ms TTI, and the base station 105-b may establish communications with the UE 115-b, as well as other UEs (not shown), based on the 1ms TTI length, and may establish a slot-aligned sTTI for low-latency communications based on the subframe time boundaries of the 1ms TTI. For example, the base station 105-b may establish an sTTI configuration in which the sTTI does not cross a subframe time boundary or a slot boundary of the 1ms TTI service.

[0102] At block 1115, the base station 105-b can identify an sTTI for SRS transmission. The sTTI for SRS transmission can be a 3-symbol sTTI in some examples, where one 3-symbol sTTI is located in each time slot boundary of a subframe that can be configured as an SRS subframe. In some examples, the base station 105-b can configure the SRS sTTI as a cell-specific SRS sTTI, and can configure the UE 115-b with a UE-specific sTTI to be used for SRS transmission. In some cases, the cell-specific sTTI can be in a subframe that is configured as a cell-specific SRS subframe for the 1ms TTI service, even though the cell-specific sTTI can be in other subframes.

[0103] At block 1120, the base station 105-b may generate configuration information for SRS transmission. The configuration information may include, for example, information about cell-specific sTTIs and UE-specific sTTIs. In some cases, the configuration information may include sTTI patterns and symbol patterns in sTTIs, as well as symbols and uplink resources to be used for SRS transmissions. In some cases, the configuration information may include multiplexing information that the UE 115-b may use to multiplex SRS transmissions with other transmissions (such as DMRS transmissions) in a symbol configured with SRS resources. The base station 105-b may send the configuration information 1125 to the UE 115-b.

[0104] At block 1130, the base station 105-b may allocate uplink resources for an sTTI for an uplink transmission from the UE 115-b. The base station 105-b may allocate sTTI resources based on, for example, cached information for low-latency services for the UE 115-b. The allocated resources may include, for example, two or more sTTIs that may be configured for SRS transmissions, and the base station 105-b may expect to receive SRS transmissions in the two or more allocated sTTIs. An indication of the allocated resources may be provided in a DCI 1135 sent to the UE 115-b.

[0105] In some examples, the base station 105-b can configure the UE 115-b to send a non-periodic SRS, and the SRS transmission / location can be indicated in the DCI 1135. In some examples, the SRS transmission / location can also be indicated in the DL grant, which can indicate that the UE is to send a sPUCCH transmission. For example, a [DMRS, data, SRS] pattern can be used on a 3-symbol sTTI, where [DMRS, data] is configured in the sPUCCH transmission and the SRS transmission is implicitly indicated without a specific grant. In other cases, this SRS transmission can be explicitly notified by the base station 105-b.

[0106] At block 1140, UE 115-b can identify the sTTI for uplink transmission. The uplink sTTI can be identified based on, for example, an uplink grant from base station 105-b. In addition, if 2-symbol and 3-symbol sTTIs are allocated to UE 115-b, the sTTI mode for uplink transmission can be identified.

[0107] At block 1145, UE 115-b may identify an sTTI for SRS transmission. The SRS sTTI may be identified, for example, based on configuration information 1125, DCI 1135, or a combination thereof. UE 115-b may also identify symbols and uplink resources in the sTTI for SRS transmission. In an example where UE 115-b is configured to send periodic SRS, the SRS sTTI and symbols may be identified based on a cell-specific SRS sTTI and a UE-specific SRS sTTI, and the UE 115-b may identify the sTTI for SRS transmission when its UE-specific SRS sTTI matches the cell-specific SRS sTTI.

[0108] At block 1150, UE 115-b may generate uplink data and SRS transmissions. The uplink data may include low-latency data to be sent to the base station 105-b, and the SRS transmission may be located in an SRS symbol in an sTTI. The UE 115-b may send an uplink transmission 1155 to the base station 105-b using the allocated sTTI. As mentioned above, the uplink transmission 1155 may include uplink data, DMRS transmissions, SRS transmissions, or any combination thereof.

[0109] At block 1160, the base station 105-b may perform signal processing for the uplink transmission. The received signal processing may include, for example, processing of an SRS transmission to determine uplink channel quality on a frequency band associated with the SRS transmission, uplink timing information based on the SRS transmission, etc. The received signal processing may also include demodulation and decoding of uplink data and generation of feedback (e.g., HARQ ACK / NACK feedback) to indicate successful or unsuccessful reception of the uplink data.

[0110] Fig.12 A block diagram 1200 illustrates a wireless device 1205 that supports transmission of a sounding reference signal in low-latency wireless transmissions in accordance with various aspects of the present disclosure. The wireless device 1205 may be a reference Figure 1 An example of aspects of a user equipment (UE) 115 is described. The wireless device 1205 may include a receiver 1210, a UE sTTI manager 1215, and a transmitter 1220. The wireless device 1205 may also include a processor. Each of these components may communicate with each other (e.g., via one or more buses).

[0111] Receiver 1210 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information about sounding reference signal transmission in low-latency wireless transmissions, etc.). The information may be passed to other components of the device. Receiver 1210 may be a reference Fig.15 Examples of aspects of transceiver 1535 are described.

[0112] UE sTTI manager 1215 can be a reference Fig.15 Examples of aspects of the UE sTTI manager 1515 are described.

[0113] At least one of the UE sTTI manager 1215 and / or its various subcomponents may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions of at least some of the UE sTTI manager 1215 and / or its various subcomponents may be performed by 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, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described in the present disclosure. At least some of the UE sTTI manager 1215 and / or its various subcomponents may be physically located in various locations, including being distributed so that a portion of the functions are implemented by one or more physical devices at different physical locations. In some examples, at least some of the UE sTTI manager 1215 and / or its various subcomponents may be discrete and different components according to various aspects of the present disclosure. In other examples, at least some of the UE sTTI manager 1215 and / or its various subcomponents may be combined with one or more other hardware components, including but not limited to I / O components, a transceiver, a network server, another computing device, one or more other components described in the present disclosure, or combinations thereof according to various aspects of the present disclosure.

[0114] The UE sTTI manager 1215 can identify a sTTI set for uplink transmission of a first wireless service, the sTTI set being within a subframe time boundary of a subframe of a second service, identify two or more sTTIs in the sTTI set for transmitting a sounding reference signal (SRS) transmission within the subframe time boundary, and send one or more SRS transmissions in at least one sTTI of the two or more sTTIs.

[0115] Transmitter 1220 may transmit signals generated by other components of the device. In some examples, transmitter 1220 may coexist with receiver 1210 in a transceiver module. For example, transmitter 1220 may be a reference Fig.15 Examples of aspects of the transceiver 1535 are described. The transmitter 1220 may include a single antenna, or it may include a group of antennas.

[0116] Fig.13 A block diagram 1300 illustrates a wireless device 1305 that supports transmission of a sounding reference signal in low-latency wireless transmissions in accordance with various aspects of the present disclosure. The wireless device 1305 may be a reference Figure 1 and 12An example of aspects of a wireless device 1205 or UE 115 is described. The wireless device 1305 may include a receiver 1310, a UE sTTI manager 1315, and a transmitter 1320. The wireless device 1305 may also include a processor. Each of these components may communicate with each other (e.g., via one or more buses).

[0117] Receiver 1310 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information about sounding reference signal transmission in low-latency wireless transmissions, etc.). Information may be passed to other components of the device. Receiver 1310 may be a reference Fig.15 Examples of aspects of transceiver 1535 are described.

[0118] UE sTTI manager 1315 can be a reference Fig.15 An example of aspects of the UE sTTI manager 1515 is described. The UE sTTI manager 1315 may also include a sTTI identification component 1325, an SRS identification component 1330, and an SRS generation component 1335.

[0119] The sTTI identification component 1325 can identify a set of sTTIs for uplink transmission of the first wireless service, the set of sTTIs being within a subframe time boundary of a subframe of the second wireless service. In some cases, a first subset of the set of sTTIs can be identified as each spanning two OFDM symbols, and a second subset of the set of sTTIs can be identified as each spanning three OFDM symbols.

[0120] The SRS identification component 1330 can identify two or more sTTIs in the sTTI set for transmitting one or more SRS transmissions within the subframe time boundary, and configure two or more sTTIs of the second subset for one or more SRS transmissions. In some cases, several SRS transmissions within the subframe time boundary can be configured by the base station. The SRS generation component 1335 can generate an SRS pattern and send the one or more SRS transmissions through the transmitter 1320.

[0121] Transmitter 1320 may transmit signals generated by other components of the device. In some examples, transmitter 1320 may coexist with receiver 1310 in a transceiver module. For example, transmitter 1320 may be a reference Fig.15 Examples of aspects of the transceiver 1535 are described. The transmitter 1320 may include a single antenna, or it may include a group of antennas.

[0122] Fig.14A block diagram 1400 of a UE sTTI manager 1415 is shown that supports transmission of a sounding reference signal in low-latency wireless transmissions according to various aspects of the present disclosure. The UE sTTI manager 1415 may be a reference Fig.12 , 13 15 and 15. The UE sTTI manager 1415 may include an sTTI identification component 1420, an SRS identification component 1425, an SRS generation component 1430, an SRS symbol selection component 1435, an SRS frequency selection component 1440, an SRS configuration component 1445, and a multiplexing component 1450. Each of these modules can communicate with each other directly or indirectly (e.g., through one or more buses).

[0123] The sTTI identification component 1420 can identify a set of sTTIs for uplink transmission of a first wireless service, the set of sTTIs being within a subframe time boundary of a subframe of a second wireless service, identify a first subset of the set of sTTIs, each of which spans two OFDM symbols, and identify a second subset of the set of sTTIs, each of which spans three OFDM symbols.

[0124] The SRS identification component 1425 can identify two or more sTTIs in the sTTI set for transmitting one or more SRS transmissions within the subframe time boundary, and configure two or more sTTIs of the second subset for one or more SRS transmissions. In some cases, several SRS transmissions within the subframe time boundary can be configured by the base station. The SRS generation component 1430 can generate an SRS pattern and send the one or more SRS transmissions.

[0125] The SRS symbol selection component 1435 can select the SRS symbol position in an sTTI. In some examples, the SRS symbol position in the first time slot can be selected to be the initial symbol or the last symbol of the associated three-symbol sTTI. In some cases, the SRS symbol position in the second time slot is selected to be the last symbol of the associated three-symbol sTTI. In some cases, identifying the second subset includes identifying the first three-symbol sTTI as the initial sTTI of the first time slot within the subframe time boundary, identifying the second three-symbol sTTI as the last sTTI of the second time slot within the subframe time boundary, and identifying the first or initial SRS symbol in the first three-symbol sTTI for the first SRS transmission, and the second SRS symbol in the second three-symbol sTTI for the second SRS transmission, wherein the second SRS symbol of the first subframe is adjacent to the first SRS symbol of the subsequent subframe. In some cases, the positions of the first SRS symbol and the second SRS symbol are selected to provide a reduced transition time for a change in one or more of uplink transmit power or resource block allocation associated with the first SRS transmission and the second SRS transmission. In some cases, identifying the second subset includes identifying the last sTTI in each of the first time slot and the second time slot within the subframe time boundary as a three-symbol sTTI. In some cases, an SRS symbol position in each sTTI of the second subset is selected to provide time diversity between subsequent SRS transmissions and a frequency band for subsequent SRS transmissions is selected to provide frequency diversity between the subsequent SRS transmissions.

[0126] In some cases, two or more two-symbol sTTIs in each of the first time slot and the second time slot within the subframe time boundary are configured for SRS transmission. In some cases, one or both of the OFDM symbols in the two or more two-symbol sTTIs are configured for SRS transmission.

[0127] The SRS frequency selection component 1440 can select a first frequency band for the first SRS transmission, select a second frequency band different from the first frequency band for the second SRS transmission, and the first frequency band and the second frequency band are selected to provide frequency diversity between the first SRS transmission and the second SRS transmission. In some cases, the first bandwidth for the one or more SRS transmissions can be identified based on one or more of the channel bandwidth or sTTI length of the uplink transmission. In some cases, the first bandwidth of the first SRS transmission is increased relative to the second bandwidth of one or more other SRS transmissions associated with the second wireless service.

[0128] The SRS configuration component 1445 may, in some examples, identify an aperiodic or periodic configuration of an SRS transmission. The SRS configuration component 1445 may, for example, receive an aperiodic configuration in an uplink grant indicating resources for one or more SRS transmissions, receive a downlink grant indicating that an uplink control channel transmission is to be sent, and determine to send the one or more SRS transmissions based on the downlink grant. For periodic configuration, the SRS configuration component 1445 may receive configuration information indicating resources for periodic SRS transmission. In some cases, the periodic configuration information includes an indication of a cell-specific sTTI and a UE-specific sTTI to be used for SRS transmission, and identifies the first sTTI for SRS transmission when the first sTTI corresponds to both a cell-specific sTTI and a UE-specific sTTI. In some cases, an indication that data and DMRS are to be sent in two symbols of a three-symbol sTTI may be received, and it may be determined that SRS is to be sent in the third symbol of the three-symbol sTTI. In some cases, the one or more SRS transmissions are used as filler in one or more sTTIs that originally do not contain uplink transmissions.

[0129] The multiplexing component 1450 may multiplex the DMRS with the first SRS in a first symbol configured for both DMRS and SRS transmission. In some cases, the multiplexing includes sending the DMRS in a first interlace of the first symbol and sending the first SRS in a second interlace of the first symbol. In some cases, the multiplexing includes sending the DMRS in a first interlace of the first symbol using a first cyclic shift and sending the first SRS in a first interlace of the first symbol using a second cyclic shift. In some cases, the multiplexing includes sending the DMRS using a first antenna port set and sending the first SRS using a second antenna port set different from the first antenna port set.

[0130] Fig.15 A schematic diagram of a system 1500 including a device 1505 supporting transmission of a sounding reference signal in low-latency wireless transmission according to various aspects of the present disclosure is shown. The device 1505 may be, for example, as described above with reference to Figure 1 , 12 13 and 1505, or include components thereof. The device 1505 may include components for two-way voice and data communications, including components for sending and receiving communications, including a UE sTTI manager 1515, a processor 1520, a memory 1525, software 1530, a transceiver 1535, an antenna 1540, and an I / O controller 1545. These components may communicate electronically via one or more buses (e.g., bus 1510). The device 1505 may communicate wirelessly with one or more base stations 105.

[0131] Processor 1520 may include an intelligent hardware device (e.g., a general purpose processor, a DSP, a central processing unit (CPU), a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof). In some cases, processor 1520 may be configured to operate a memory array using a memory controller. In other cases, a memory manager may be integrated into processor 1520. Processor 1520 may be configured to execute computer readable instructions stored in the memory to perform various functions (e.g., functions or tasks to support transmission of a sounding reference signal in a low-latency wireless transmission).

[0132] Memory 1525 may include random access memory (RAM) and read-only memory (ROM). Memory 1525 may store computer-readable, computer-executable software 1530, which includes instructions that, when executed, cause the processor to perform the various functions described herein. In some cases, memory 1525 may, among other things, contain a basic input / output system (BIOS), which may control basic hardware and / or software operations such as interacting with peripheral components or devices.

[0133] The software 1530 may include code for implementing aspects of the present disclosure, including code for supporting sounding reference signal transmission in low-latency wireless transmissions. The software 1530 may be stored in a permanent computer-readable medium such as system memory or other storage. In some cases, the software 1530 may not be directly executed by the processor but may enable a computer (e.g., when compiled and executed) to perform the functions described in this application.

[0134] The transceiver 1535 can communicate bidirectionally through one or more antennas, wired or wireless links as described above. For example, the transceiver 1535 can represent a wireless transceiver and can communicate bidirectionally with another wireless transceiver. The transceiver 1535 can also include a modem for modulating packets and providing the modulated packets to an antenna for transmission, and demodulating the packets received from the antenna.

[0135] In some cases, the wireless device may include a single antenna 1540. However, in some cases, the device may have more than one antenna 1540 that are capable of concurrently sending or receiving multiple wireless transmissions.

[0136] I / O controller 1545 can manage input and output signals for device 1505. I / O controller 1545 can also manage peripheral devices that are not integrated into device 1505. In some cases, I / O controller 1545 can represent a physical connection or port to an external device. In some cases, I / O controller 1545 can be implemented as, for example, Or another well-known operating system. In other cases, I / O controller 1545 can represent or interact with a modem, keyboard, mouse, touch screen or similar device. In some cases, I / O controller 1545 can be implemented as a part of a processor. In some cases, a user can interact with device 1505 through I / O controller 1545 or through hardware components controlled by I / O controller 1545.

[0137] Fig.16 A block diagram 1600 illustrates a wireless device 1605 that supports transmission of a sounding reference signal in low-latency wireless transmissions in accordance with various aspects of the present disclosure. The wireless device 1605 may be a reference Figure 1 An example of aspects of the base station 105 is described. The wireless device 1605 may include a receiver 1610, a base station sTTI manager 1615, and a transmitter 1620. The wireless device 1605 may also include a processor. Each of these components may communicate with each other (e.g., via one or more buses).

[0138] Receiver 1610 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information about sounding reference signal transmission in low-latency wireless transmissions, etc.). The information may be passed to other components of the device. Receiver 1610 may be a reference Fig.19 Examples of aspects of transceiver 1935 are described.

[0139] The base station sTTI manager 1615 can be a reference Fig.19 An example of aspects of a base station sTTI manager 1915 is described.

[0140] At least one of the base station sTTI manager 1615 and / or its various subcomponents may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions of at least some of the base station sTTI manager 1615 and / or its various subcomponents may be performed by a general purpose processor, DSP, ASIC, FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described in the present disclosure. At least some of the base station sTTI manager 1615 and / or its various subcomponents may be physically located in various locations, including being distributed so that a portion of the functions are implemented by one or more physical devices at different physical locations. In some examples, at least some of the base station sTTI manager 1615 and / or its various subcomponents may be discrete and different components according to various aspects of the present disclosure. In other examples, at least some of the base station sTTI manager 1615 and / or its various subcomponents may be combined with one or more other hardware components, including but not limited to I / O components, a transceiver, a network server, another computing device, one or more other components described in the present disclosure, or combinations thereof according to various aspects of the present disclosure.

[0141] The base station sTTI manager 1615 can identify a sTTI set for uplink transmission of a first wireless service, the sTTI set being within a subframe time boundary of a subframe of a second service, identify two or more sTTIs in the sTTI set for transmitting a sounding reference signal (SRS) transmission within the subframe time boundary, and configure the UE to send one or more SRS transmissions in at least one sTTI of the two or more sTTIs.

[0142] Transmitter 1620 may transmit signals generated by other components of the device. In some examples, transmitter 1620 may coexist with receiver 1610 in a transceiver module. For example, transmitter 1620 may be a reference Fig.19 Examples of aspects of the transceiver 1935 are described. The transmitter 1620 may include a single antenna, or it may include a group of antennas.

[0143] Fig.17 A block diagram 1700 illustrates a wireless device 1705 that supports transmission of a sounding reference signal in low-latency wireless transmissions in accordance with various aspects of the present disclosure. The wireless device 1705 may be a reference Figure 1 and 16An example of aspects of a wireless device 1605 or base station 105 is described. The wireless device 1705 may include a receiver 1710, a base station sTTI manager 1715, and a transmitter 1720. The wireless device 1705 may also include a processor. Each of these components may communicate with each other (e.g., via one or more buses).

[0144] Receiver 1710 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information about sounding reference signal transmissions in low-latency wireless transmissions, etc.). The information may be passed to other components of the device. Receiver 1710 may be a reference Fig.19 Examples of aspects of transceiver 1935 are described.

[0145] The base station sTTI manager 1715 can be a reference Fig.19 An example of aspects of a base station sTTI manager 1915 is described. The base station sTTI manager 1715 may also include a sTTI identification component 1725, an SRS identification component 1730, and an SRS configuration component 1735.

[0146] The sTTI identification component 1725 can identify a set of sTTIs for uplink transmission of the first wireless service, the set of sTTIs being within a subframe time boundary of a subframe of the second wireless service, configure a first subset of the set of sTTIs each spanning two OFDM symbols and a second subset of the set of sTTIs each spanning three OFDM symbols. In some cases, configuring the second subset includes identifying the last sTTI in each of the first time slot and the second time slot within the subframe time boundary as a three-symbol sTTI.

[0147] The SRS identification component 1730 can identify two or more sTTIs in the sTTI set for transmitting one or more SRS transmissions within the subframe time boundary.

[0148] The SRS configuration component 1735 can configure the UE to send one or more SRS transmissions. In some cases, the SRS configuration component 1735 can configure two or more sTTIs of the second subset for the one or more SRS transmissions. In some cases, the SRS configuration component 1735 can send a non-periodic configuration in an uplink grant to the UE, which indicates the resources for one or more SRS transmissions, or send a downlink grant to the UE indicating that an uplink control channel transmission is to be sent and the one or more SRS transmissions are to be sent. In some examples, the SRS configuration component 1735 can send configuration information indicating resources for periodic SRS transmissions, such as an indication of a cell-specific sTTI and a UE-specific sTTI to be used for SRS transmission, wherein the first sTTI for SRS transmission can be identified when the first sTTI corresponds to both a cell-specific sTTI and a UE-specific sTTI. In some cases, the determination to send the one or more SRS transmissions is based on an indication in the downlink grant that data and DMRS are to be sent in two-symbol or three-symbol sTTIs.

[0149] Transmitter 1720 may transmit signals generated by other components of the device. In some examples, transmitter 1720 may coexist with receiver 1710 in a transceiver module. For example, transmitter 1720 may be a reference Fig.19 Examples of aspects of the transceiver 1935 are described. The transmitter 1720 may include a single antenna, or it may include a group of antennas.

[0150] Fig.18 Block diagram 1800 of a base station sTTI manager 1815 is shown to support transmission of a sounding reference signal in low-latency wireless transmissions in accordance with various aspects of the present disclosure. The base station sTTI manager 1815 may be a reference Fig.16 , 17 19 and 19 illustrate examples of aspects of a base station sTTI manager 1915. The base station sTTI manager 1815 may include an sTTI identification component 1820, an SRS identification component 1825, an SRS configuration component 1830, an SRS symbol selection component 1835, an SRS frequency selection component 1840, and a multiplexing component 1845. Each of these modules may communicate with each other directly or indirectly (e.g., via one or more buses).

[0151] The TTI identification component 1820 can identify a set of sTTIs for uplink transmission of the first wireless service, the set of sTTIs being within a subframe time boundary of a subframe of the second wireless service, and configuring a first subset of the set of sTTIs each spanning two OFDM symbols and a second subset of the set of sTTIs each spanning three OFDM symbols. In some cases, configuring the second subset includes identifying the last sTTI in each of the first time slot and the second time slot within the subframe time boundary as a three-symbol sTTI.

[0152] The SRS identification component 1825 can identify two or more sTTIs in the sTTI set for transmitting one or more SRS transmissions within the subframe time boundary.

[0153] The SRS configuration component 1830 can configure the UE to send one or more SRS transmissions. In some cases, the SRS configuration component 1830 can configure two or more sTTIs of the second subset for the one or more SRS transmissions. In some cases, the SRS configuration component 1830 can send a non-periodic configuration in an uplink grant to the UE, which indicates the resources for one or more SRS transmissions, or send a downlink grant to the UE indicating that an uplink control channel transmission is to be sent and the one or more SRS transmissions are to be sent. In some examples, the SRS configuration component 1830 can send configuration information indicating resources for periodic SRS transmissions, such as an indication of a cell-specific sTTI and a UE-specific sTTI to be used for SRS transmission, wherein the first sTTI for SRS transmission can be identified when the first sTTI corresponds to both a cell-specific sTTI and a UE-specific sTTI. In some cases, the determination to send the one or more SRS transmissions is based on an indication in the downlink grant that data and DMRS are to be sent in two-symbol or three-symbol sTTIs.

[0154] The SRS symbol selection component 1835 can, in some cases, configure a first three-symbol sTTI as an initial sTTI of a first time slot within the subframe time boundary, configure a second three-symbol sTTI as a last sTTI of a second time slot within the subframe time boundary, and configure a first SRS symbol in the first three-symbol sTTI for a first SRS transmission, a second SRS symbol in the second three-symbol sTTI for a second SRS transmission, the second symbol of the first subframe being adjacent to the first symbol of a subsequent subframe. In some cases, the positions of the first SRS symbol and the second SRS symbol are selected to provide a reduced transition time for a change in one or more of uplink transmit power or resource block allocation associated with the first SRS transmission and the second SRS transmission.

[0155] The SRS frequency selection component 1840 can identify a first bandwidth of a first SRS transmission of the one or more SRS transmissions based on one or more of a channel bandwidth or an sTTI length of the uplink transmission.

[0156] The multiplexing component 1845 can configure the UE to multiplex the DMRS with the first SRS in a first symbol, receive the DMRS in a first interlace of the first symbol, receive the first SRS transmission in a second interlace of the first symbol, receive the DMRS in the first interlace of the first symbol using a first cyclic shift, receive the first SRS in the first interlace of the first symbol using a second cyclic shift, receive the DMRS using a first antenna port set, and receive the first SRS using a second antenna port set different from the first antenna port set.

[0157] Fig.19 A schematic diagram of a system 1900 including a device 1905 supporting transmission of a sounding reference signal in low-latency wireless transmission according to various aspects of the present disclosure is shown. The device 1905 may be, for example, as described above with reference to Figure 1 The example of the base station 105 described herein may include components thereof. The device 1905 may include components for two-way voice and data communications, including components for sending and receiving communications, including a base station sTTI manager 1915, a processor 1920, a memory 1925, software 1930, a transceiver 1935, an antenna 1940, a network communication manager 1945, and a base station communication manager 1950. These components may communicate electronically via one or more buses (e.g., bus 1910). The device 1905 may communicate wirelessly with one or more UEs 115.

[0158] The processor 1920 may include an intelligent hardware device (e.g., a general purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof). In some cases, the processor 1920 may be configured to operate a memory array using a memory controller. In other cases, the memory manager may be integrated into the processor 1920. The processor 1920 may be configured to execute computer readable instructions stored in the memory to perform various functions (e.g., functions or tasks to support transmission of a sounding reference signal in a low-latency wireless transmission).

[0159] Memory 1925 may include RAM and ROM. Memory 1925 may store computer-readable, computer-executable software 1930, which includes instructions that, when executed, cause the processor to perform various functions described in this application. In some cases, memory 1925 may, among other things, contain BIOS, which may control basic hardware and / or software operations such as interacting with peripheral components or devices.

[0160] The software 1930 may include code for implementing aspects of the present disclosure, including code for supporting sounding reference signal transmission in low-latency wireless transmissions. The software 1930 may be stored in a permanent computer-readable medium such as system memory or other storage. In some cases, the software 1930 may not be directly executed by the processor but may enable a computer (e.g., when compiled and executed) to perform the functions described in this application.

[0161] The transceiver 1935 can communicate bidirectionally through one or more antennas, wired or wireless links as described above. For example, the transceiver 1935 can represent a wireless transceiver and can communicate bidirectionally with another wireless transceiver. The transceiver 1935 can also include a modem for modulating packets and providing the modulated packets to an antenna for transmission, and demodulating the packets received from the antenna.

[0162] In some cases, the wireless device may include a single antenna 1940. However, in some cases, the device may have more than one antenna 1940 that are capable of concurrently sending or receiving multiple wireless transmissions.

[0163] The network communications manager 1945 may manage communications with the core network (eg, via one or more wired backhaul links). For example, the network communications manager 1945 may manage the transfer of data communications for client devices such as one or more UEs 115.

[0164] The base station communication manager 1950 may manage communications with other base stations 105 and may include a controller or scheduler for controlling communications with the UE 115 in cooperation with the other base stations 195. For example, the base station communication manager 1950 may coordinate the scheduling of transmissions to the UE 115 for various interference mitigation techniques such as beamforming or joint transmission. In some examples, the base station communication manager 1950 may provide an X2 interface in a long term evolution (LTE) / LTE-A wireless communication network technology to provide communications between base stations 105.

[0165] Fig. 20 A flow chart depicting a method 2000 for sounding reference signal transmission in low-latency wireless transmission according to aspects of the present disclosure is shown. The operations of the method 2000 may be implemented by a UE 115 or a component thereof as described herein. For example, the operations of the method 2000 may be implemented by a UE 115 or a component thereof as described herein. Figures 12 to 15 The UE sTTI manager described herein may be executed. In some examples, the UE 115 may execute a code set to control the functional elements of the device to perform the functions described below. Additionally or alternatively, the UE 115 may use dedicated hardware to perform aspects of the functions described below.

[0166] At block 2005, the UE 115 may identify a set of sTTIs for uplink transmissions of the first wireless service that are within a subframe time boundary of a subframe of the second service. The operation of block 2005 may be performed according to reference Figures 1 to 11 In some examples, aspects of the operation of block 2005 may be performed by reference to Figures 12 to 15 Describes the implementation of the sTTI identification component.

[0167] At block 2010, the UE 115 may identify two or more sTTIs in the sTTI set for transmitting SRS transmissions within the subframe time boundary. The operation of block 2010 may be based on reference Figures 1 to 11 In some examples, aspects of the operations of block 2010 may be performed by reference to Figures 12 to 15 Describes the SRS identification component implementation.

[0168] At block 2015, the UE 115 may send one or more SRS transmissions in at least one of the two or more sTTIs. The operation of block 2015 may be performed according to reference Figures 1 to 11 In some examples, aspects of the operations of block 2015 may be performed by reference to Figures 12 to 15 The SRS generation component described in this article is implemented in conjunction with Fig.12 or the transmitter 1220 or 1320 described in 13, or reference Fig.15 Antenna 1540 and transceiver 1535 are depicted operating in cooperation.

[0169] Fig.21 A flow chart depicting a method 2100 for sounding reference signal transmission in low-latency wireless transmission according to aspects of the present disclosure is shown. The operations of the method 2100 may be implemented by a UE 115 or a component thereof as described herein. For example, the operations of the method 2100 may be implemented by a UE 115 or a component thereof as described herein. Figures 12 to 15 The UE sTTI manager described herein may be executed. In some examples, the UE 115 may execute a code set to control the functional elements of the device to perform the functions described below. Additionally or alternatively, the UE 115 may use dedicated hardware to perform aspects of the functions described below.

[0170] At block 2105, the UE 115 may identify a set of sTTIs for uplink transmission of the first wireless service that are within a subframe time boundary of a subframe of the second service. The operation of block 2105 may be performed according to reference Figures 1 to 11 In some examples, aspects of the operation of block 2105 may be performed by reference to Figures 12 to 15Describes the implementation of the sTTI identification component.

[0171] At block 2110, the UE 115 may identify two or more sTTIs in the sTTI set for transmitting SRS transmissions within the subframe time boundary. The operation of block 2110 may be based on reference Figures 1 to 11 In some examples, aspects of the operation of block 2110 may be performed by reference to Figures 12 to 15 Describes the SRS identification component implementation.

[0172] At block 2115, the UE 115 may identify a first subset of the sTTI set, each of which spans two OFDM symbols, and a second subset of the sTTI set, each of which spans three OFDM symbols. The operation of block 2115 may be based on reference Figures 1 to 11 In some examples, aspects of the operation of block 2115 may be performed by reference to Figures 12 to 15 Describes the implementation of the sTTI identification component.

[0173] At block 2120, the UE 115 may configure two or more sTTIs of the second subset for the SRS transmission. The operation of block 2120 may be based on reference Figures 1 to 11 In some examples, aspects of the operations of block 2120 may be performed by reference to Figures 12 to 15 Describes the SRS identification component implementation.

[0174] At block 2125, the UE 115 may send one or more SRS transmissions in at least one of the two or more sTTIs. The operation of block 2125 may be performed according to reference Figures 1 to 11 In some examples, aspects of the operation of block 2125 may be performed by reference to Figures 12 to 15 The SRS generation component described in this article is implemented in conjunction with Fig.12 or the transmitter 1220 or 1320 described in 13, or reference Fig.15 Antenna 1540 and transceiver 1535 are depicted operating in cooperation.

[0175] Fig. 22 A flow chart depicting a method 2200 for sounding reference signal transmission in low-latency wireless transmission according to aspects of the present disclosure is shown. The operations of the method 2200 may be implemented by a UE 115 or a component thereof as described herein. For example, the operations of the method 2200 may be implemented by a UE 115 or a component thereof as described herein. Figures 12 to 15 The UE sTTI manager described herein may be executed. In some examples, the UE 115 may execute a code set to control the functional elements of the device to perform the functions described below. Additionally or alternatively, the UE 115 may use dedicated hardware to perform aspects of the functions described below.

[0176] At block 2205, the UE 115 may identify a set of sTTIs for uplink transmission of the first wireless service that are within a subframe time boundary of a subframe of the second service. The operation of block 2205 may be performed according to reference Figures 1 to 11 In some examples, aspects of the operation of block 2205 may be performed by reference to Figures 12 to 15 Describes the implementation of the sTTI identification component.

[0177] At block 2210, the UE 115 may identify two or more sTTIs in the sTTI set for transmitting SRS transmissions within the subframe time boundary. The operation of block 2210 may be based on reference Figures 1 to 11 In some examples, aspects of the operation of block 2210 may be performed by reference to Figures 12 to 15 Describes the SRS identification component implementation.

[0178] At block 2215, UE 115 may select a first frequency band for the first SRS transmission. The operation of block 2215 may be based on reference Figures 1 to 11 In some examples, aspects of the operation of block 2215 may be performed by reference to Figures 12 to 15 Describes the implementation of the SRS frequency selection component.

[0179] At block 2220, the UE 115 may select a second frequency band different from the first frequency band for the second SRS transmission, wherein the first frequency band and the second frequency band are selected to provide frequency diversity between the first SRS transmission and the second SRS transmission. The operation of block 2220 may be based on reference Figures 1 to 11 In some examples, aspects of the operation of block 2220 may be performed by reference to Figures 12 to 15 Describes the implementation of the SRSp frequency selection component.

[0180] At block 2225, the UE 115 may send the SRS transmission. The operation of block 2225 may be based on reference Figures 1 to 11 In some examples, aspects of the operation of block 2225 may be performed by reference to Figures 12 to 15 The SRS generation component described in this article is implemented in conjunction with Fig.12 or the transmitter 1220 or 1320 described in 13, or reference Fig.15 Antenna 1540 and transceiver 1535 are depicted operating in cooperation.

[0181] Fig.23A flow chart depicting a method 2300 for sounding reference signal transmission in low-latency wireless transmission according to aspects of the present disclosure is shown. The operations of the method 2300 may be implemented by a UE 115 or a component thereof as described herein. For example, the operations of the method 2300 may be implemented by a UE 115 or a component thereof as described herein. Figures 12 to 15 The UE sTTI manager described herein may be executed. In some examples, the UE 115 may execute a code set to control the functional elements of the device to perform the functions described below. Additionally or alternatively, the UE 115 may use dedicated hardware to perform aspects of the functions described below.

[0182] At block 2305, the UE 115 may identify a set of sTTIs for uplink transmissions of the first wireless service that are within a subframe time boundary of a subframe of the second service. The operation of block 2305 may be performed according to reference Figures 1 to 11 In some examples, aspects of the operation of block 2305 may be performed by reference to Figures 12 to 15 Describes the implementation of the sTTI identification component.

[0183] At block 2310, the UE 115 may identify two or more sTTIs in the sTTI set for transmitting SRS transmissions within the subframe time boundary. The operation of block 2310 may be based on reference Figures 1 to 11 In some examples, aspects of the operation of block 2310 may be performed by reference to Figures 12 to 15 Describes the SRS identification component implementation.

[0184] At block 2315, the UE 115 may identify a subset of the set of sTTIs that each spans two OFDM symbols. The operation of block 2315 may be performed according to reference Figures 1 to 11 In some examples, aspects of the operation of block 2315 may be performed by reference to Figures 12 to 15 Describes the implementation of the sTTI identification component.

[0185] At block 2320, UE 115 configures two or more sTTIs of the subset for the SRS transmission. The operation of block 2320 may be performed according to reference Figures 1 to 11 In some examples, aspects of the operation of block 2320 may be performed by reference to Figures 12 to 15 Describes the SRS identification component implementation.

[0186] At block 2325, the UE 115 may send the SRS transmission. The operation of block 2325 may be performed according to reference Figures 1 to 11 In some examples, aspects of the operation of block 2325 may be performed by reference to Figures 12 to 15 The SRS generation component described in this article is implemented in conjunction with Fig.12 or the transmitter 1220 or 1320 described in 13, or reference Fig.15 Antenna 1540 and transceiver 1535 are depicted operating in cooperation.

[0187] Fig.24 A flow chart depicting a method 2400 for sounding reference signal transmission in low-latency wireless transmission according to aspects of the present disclosure is shown. The operations of the method 2400 may be implemented by a UE 115 or a component thereof as described herein. For example, the operations of the method 2400 may be implemented by a UE 115 or a component thereof as described herein. Figures 12 to 15 The UE sTTI manager described herein may be executed. In some examples, the UE 115 may execute a code set to control the functional elements of the device to perform the functions described below. Additionally or alternatively, the UE 115 may use dedicated hardware to perform aspects of the functions described below.

[0188] At block 2405, the UE 115 may receive an aperiodic configuration of resources indicating one or more SRS transmissions in an uplink grant. The operation of block 2405 may be performed according to reference Figures 1 to 11 In some examples, aspects of the operation of block 2405 may be performed by reference to Figures 12 to 15 The SRS configuration components described in this document are implemented in conjunction with the reference Fig.12 or the receiver 1210 or 1310 described in 13, or reference Fig.15 Antenna 1540 and transceiver 1535 are depicted operating in cooperation.

[0189] At block 2410, the UE 115 may identify a set of sTTIs for uplink transmissions of a first wireless service that are within a subframe time boundary of a subframe of a second service. The operation of block 2410 may be performed according to reference Figures 1 to 11 In some examples, aspects of the operation of block 2410 may be performed by reference to Figures 12 to 15 Describes the implementation of the sTTI identification component.

[0190] At block 2415, the UE 115 may identify two or more sTTIs in the sTTI set for transmitting SRS transmissions within the subframe time boundary. The operation of block 2415 may be based on reference Figures 1 to 11 In some examples, aspects of the operation of block 2415 may be performed by reference to Figures 12 to 15 Describes the SRS identification component implementation.

[0191] At block 2420, the UE 115 may send the one or more SRS transmissions. The operation of block 2420 may be based on reference Figures 1 to 11In some examples, aspects of the operations of block 2420 may be performed by reference to Figures 12 to 15 The SRS generation component described in this article is implemented in conjunction with Fig.12 or the transmitter 1220 or 1320 described in 13, or reference Fig.15 Antenna 1540 and transceiver 1535 are depicted operating in cooperation.

[0192] Fig.25 A flow chart depicting a method 2500 for sounding reference signal transmission in low-latency wireless transmission according to aspects of the present disclosure is shown. The operations of the method 2500 may be implemented by a UE 115 or a component thereof as described herein. For example, the operations of the method 2500 may be implemented by a UE 115 or a component thereof as described herein. Figures 12 to 15 The UE sTTI manager described herein may be executed. In some examples, the UE 115 may execute a code set to control the functional elements of the device to perform the functions described below. Additionally or alternatively, the UE 115 may use dedicated hardware to perform aspects of the functions described below.

[0193] At block 2505, UE 115 may receive a downlink grant indicating that an uplink control channel transmission is to be sent. The operation of block 2505 may be based on reference Figures 1 to 11 In some examples, aspects of the operation of block 2505 may be performed by reference to Figures 12 to 15 The SRS configuration components described in this document are implemented in conjunction with the reference Fig.12 or the receiver 1210 or 1310 described in 13, or reference Fig.15 Antenna 1540 and transceiver 1535 are depicted operating in cooperation.

[0194] At block 2510, UE 115 may determine to send one or more SRS transmissions based at least in part on the downlink grant. The operations of block 2510 may be based on reference Figures 1 to 11 In some examples, aspects of the operation of block 2510 may be performed by reference to Figures 12 to 15 Describes the SRS configuration component implementation.

[0195] At block 2515, the UE 115 may identify a set of sTTIs for uplink transmissions of the first wireless service that are within a subframe time boundary of a subframe of the second service. The operation of block 2515 may be performed according to reference Figures 1 to 11 In some examples, aspects of the operation of block 2515 may be performed by reference to Figures 12 to 15 Describes the implementation of the sTTI identification component.

[0196] At block 2520, the UE 115 may identify two or more sTTIs in the sTTI set for transmitting SRS transmissions within the subframe time boundary. The operation of block 2520 may be based on reference Figures 1 to 11 In some examples, aspects of the operation of block 2520 may be performed by reference to Figures 12 to 15 Describes the SRS identification component implementation.

[0197] At block 2525, the UE 115 may send the one or more SRS transmissions. The operation of block 2525 may be based on reference Figures 1 to 11 In some examples, aspects of the operation of block 2525 may be performed by reference to Figures 12 to 15 The SRS generation component described in this article is implemented in conjunction with Fig.12 or the transmitter 1220 or 1320 described in 13, or reference Fig.15 Antenna 1540 and transceiver 1535 are depicted operating in cooperation.

[0198] Fig.26 A flow chart depicting a method 2600 for sounding reference signal transmission in low-latency wireless transmission according to aspects of the present disclosure is shown. The operations of the method 2600 may be implemented by a UE 115 or a component thereof as described herein. For example, the operations of the method 2600 may be implemented by a UE 115 or a component thereof as described herein. Figures 12 to 15 The UE sTTI manager described herein may be executed. In some examples, the UE 115 may execute a code set to control the functional elements of the device to perform the functions described below. Additionally or alternatively, the UE 115 may use dedicated hardware to perform aspects of the functions described below.

[0199] At block 2605, UE 115 may receive configuration information indicating resources for periodic SRS transmission. The operation of block 2605 may be based on reference Figures 1 to 11 In some examples, aspects of the operation of block 2605 may be described by reference to Figures 12 to 15 The SRS configuration components described in this document are implemented in conjunction with the reference Fig.12 or the receiver 1210 or 1310 described in 13, or reference Fig.15 Antenna 1540 and transceiver 1535 are depicted operating in cooperation.

[0200] At block 2610, the UE 115 may identify a set of sTTIs for uplink transmissions of a first wireless service that are within a subframe time boundary of a subframe of a second service. The operation of block 2610 may be performed according to reference Figures 1 to 11 In some examples, aspects of the operation of block 2610 may be performed by reference to Figures 12 to 15Describes the implementation of the sTTI identification component.

[0201] At block 2615, the UE 115 may identify two or more sTTIs in the sTTI set for transmitting SRS transmissions within the subframe time boundary. The operation of block 2615 may be based on reference Figures 1 to 11 In some examples, aspects of the operation of block 2615 may be performed by reference to Figures 12 to 15 Describes the SRS identification component implementation.

[0202] At block 2620, the UE 115 may send the one or more SRS transmissions. The operation of block 2620 may be based on reference Figures 1 to 11 In some examples, aspects of the operation of block 2620 may be performed by reference to Figures 12 to 15 The SRS generation component described in this article is implemented in conjunction with Fig.12 or the transmitter 1220 or 1320 described in 13, or reference Fig.15 Antenna 1540 and transceiver 1535 are depicted operating in cooperation.

[0203] Fig. 27 A flow chart depicting a method 2700 for sounding reference signal transmission in low-latency wireless transmission according to aspects of the present disclosure is shown. The operations of the method 2700 may be implemented by a UE 115 or a component thereof as described herein. For example, the operations of the method 2700 may be implemented by a UE 115 or a component thereof as described herein. Figures 12 to 15 The UE sTTI manager described herein may be executed. In some examples, the UE 115 may execute a code set to control the functional elements of the device to perform the functions described below. Additionally or alternatively, the UE 115 may use dedicated hardware to perform aspects of the functions described below.

[0204] At block 2705, the UE 115 may identify a set of sTTIs for uplink transmission of the first wireless service that are within a subframe time boundary of a subframe of the second service. The operation of block 2705 may be performed according to reference Figures 1 to 11 In some examples, aspects of the operation of block 2705 may be performed by reference to Figures 12 to 15 Describes the implementation of the sTTI identification component.

[0205] At block 2710, the UE 115 may identify two or more sTTIs in the sTTI set for transmitting SRS transmissions within the subframe time boundary. The operation of block 2710 may be based on reference Figures 1 to 11 In some examples, aspects of the operation of block 2710 may be performed by reference to Figures 12 to 15 Describes the SRS identification component implementation.

[0206] At block 2715, the UE 115 may multiplex the DMRS with the first SRS in a first symbol configured for both DMRS and SRS transmission. The operation of block 2715 may be based on reference Figures 1 to 11 In some examples, aspects of the operation of block 2715 may be described by reference to Figures 12 to 15 Describes the implementation of a reusable component.

[0207] At block 2720, the UE 115 may send the one or more SRS transmissions. The operation of block 2720 may be based on reference Figures 1 to 11 In some examples, aspects of the operation of block 2720 may be performed by reference to Figures 12 to 15 The SRS generation component described in this article is implemented in conjunction with Fig.12 or the transmitter 1220 or 1320 described in 13, or reference Fig.15 Antenna 1540 and transceiver 1535 are depicted operating in cooperation.

[0208] Fig.28 A flow chart depicting a method 2800 for sounding reference signal transmission in low-latency wireless transmission according to aspects of the present disclosure is shown. The operations of the method 2800 may be implemented by a base station 105 or components thereof as described herein. For example, the operations of the method 2800 may be implemented by a base station 105 or components thereof as described herein. Figures 16 to 19 The base station sTTI manager described herein is executed. In some examples, the base station 105 may execute a code set to control the functional elements of the device to perform the functions described below. Additionally or alternatively, the base station 105 may use dedicated hardware to perform aspects of the functions described below.

[0209] At block 2805, the base station 105 may identify a set of sTTIs for uplink transmission of the first wireless service that are within a subframe time boundary of a subframe of the second service. The operation of block 2805 may be performed according to reference Figures 1 to 11 In some examples, aspects of the operation of block 2805 may be performed by reference to Figures 16 to 19 Describes the implementation of the sTTI identification component.

[0210] At block 2810, the base station 105 may identify two or more sTTIs in the sTTI set for transmitting SRS transmissions within the subframe time boundary. The operation of block 2810 may be based on reference Figures 1 to 11 In some examples, aspects of the operation of block 2810 may be performed by reference to Figures 16 to 19 Describes the SRS identification component implementation.

[0211] At block 2815, the base station 105 may configure the UE to send one or more SRS transmissions in at least one sTTI of the two or more sTTIs. The operation of block 2815 may be performed according to reference Figures 1 to 11 In some examples, aspects of the operation of block 2815 may be performed by reference to Figures 16 to 19 Describes the SRS configuration component implementation.

[0212] Fig.29 A flow chart depicting a method 2900 for sounding reference signal transmission in low-latency wireless transmission according to aspects of the present disclosure is shown. The operations of the method 2900 may be implemented by a base station 105 or components thereof as described herein. For example, the operations of the method 2900 may be implemented by reference to Figures 16 to 19 The base station sTTI manager described herein is executed. In some examples, the base station 105 may execute a code set to control the functional elements of the device to perform the functions described below. Additionally or alternatively, the base station 105 may use dedicated hardware to perform aspects of the functions described below.

[0213] At block 2905, the base station 105 may identify a set of sTTIs for uplink transmission of the first wireless service that are within a subframe time boundary of a subframe of the second service. The operation of block 2905 may be performed according to reference Figures 1 to 11 In some examples, aspects of the operation of block 2905 may be performed by reference to Figures 16 to 19 Describes the implementation of the sTTI identification component.

[0214] At block 2910, the base station 105 may identify two or more sTTIs in the sTTI set for transmitting SRS transmissions within the subframe time boundary. The operation of block 2910 may be based on reference Figures 1 to 11 In some examples, aspects of the operation of block 2910 may be performed by reference to Figures 16 to 19 Describes the SRS identification component implementation.

[0215] At block 2915, the base station 105 may configure a first subset of the sTTI set, each of which spans two OFDM symbols, and a second subset of the sTTI set, each of which spans three OFDM symbols. The operation of block 2915 may be performed according to reference Figures 1 to 11 In some examples, aspects of the operation of block 2915 may be performed by reference to Figures 16 to 19 Describes the implementation of the sTTI identification component.

[0216] At block 2920, the base station 105 may configure two or more sTTIs of the second subset for SRS transmission. The operation of block 2920 may be performed according to reference Figures 1 to 11In some examples, aspects of the operation of block 2920 may be performed by reference to Figures 16 to 19 Describes the SRS configuration component implementation.

[0217] At block 2925, the base station 105 may configure the UE to send one or more SRS transmissions in at least one sTTI of the two or more sTTIs. The operation of block 2925 may be performed according to reference Figures 1 to 11 In some examples, aspects of the operation of block 2925 may be performed by reference to Figures 16 to 19 Describes the SRS configuration component implementation.

[0218] Fig.30 A flow chart depicting a method 3000 for sounding reference signal transmission in low-latency wireless transmission according to aspects of the present disclosure is shown. The operations of the method 3000 may be implemented by a base station 105 or components thereof as described herein. For example, the operations of the method 3000 may be implemented by a base station 105 or components thereof as described herein. Figures 16 to 19 The base station sTTI manager described herein is executed. In some examples, the base station 105 may execute a code set to control the functional elements of the device to perform the functions described below. Additionally or alternatively, the base station 105 may use dedicated hardware to perform aspects of the functions described below.

[0219] At block 3005, the base station 105 may identify a set of sTTIs for uplink transmission of the first wireless service that are within a subframe time boundary of a subframe of the second service. The operation of block 3005 may be performed according to reference Figures 1 to 11 In some examples, aspects of the operation of block 3005 may be performed by reference to Figures 16 to 19 Describes the implementation of the sTTI identification component.

[0220] At block 3010, the base station 105 may identify two or more sTTIs in the sTTI set for transmitting SRS transmissions within the subframe time boundary. The operation of block 3010 may be based on reference Figures 1 to 11 In some examples, aspects of the operation of block 3010 may be performed by reference to Figures 16 to 19 Describes the SRS identification component implementation.

[0221] At block 3015, the base station 105 may identify a subset of the sTTI set that spans two OFDM symbols. The operation of block 3015 may be based on reference Figures 1 to 11 In some examples, aspects of the operation of block 3015 may be performed by reference to Figures 16 to 19 Describes the implementation of the sTTI identification component.

[0222] At block 3020, the base station 105 may configure two or more sTTIs of the subset for SRS transmission. The operation of block 3020 may be based on reference Figures 1 to 11 In some examples, aspects of the operation of block 3020 may be performed by reference to Figures 16 to 19 Describes the SRS configuration component implementation.

[0223] At block 3025, the base station 105 may configure the UE to send one or more SRS transmissions in at least one sTTI of the two or more sTTIs. The operation of block 3025 may be performed according to reference Figures 1 to 11 In some examples, aspects of the operation of block 3025 may be described by reference to Figures 16 to 19 Describes the SRS configuration component implementation.

[0224] Fig.31 A flow chart depicting a method 3100 for sounding reference signal transmission in low-latency wireless transmission according to aspects of the present disclosure is shown. The operations of the method 3100 may be implemented by a base station 105 or components thereof as described herein. For example, the operations of the method 3100 may be implemented by a base station 105 or components thereof as described herein. Figures 16 to 19 The base station sTTI manager described herein is executed. In some examples, the base station 105 may execute a code set to control the functional elements of the device to perform the functions described below. Additionally or alternatively, the base station 105 may use dedicated hardware to perform aspects of the functions described below.

[0225] At block 3105, the base station 105 may identify a set of sTTIs for uplink transmission of the first wireless service that are within a subframe time boundary of a subframe of the second service. The operation of block 3105 may be based on reference Figures 1 to 11 In some examples, aspects of the operation of block 3105 may be described by reference to Figures 16 to 19 Describes the implementation of the sTTI identification component.

[0226] At block 3110, the base station 105 may identify two or more sTTIs in the sTTI set for transmitting SRS transmissions within the subframe time boundary. The operation of block 3110 may be based on reference Figures 1 to 11 In some examples, aspects of the operation of block 3110 may be performed by reference to Figures 16 to 19 Describes the SRS identification component implementation.

[0227] At block 3115, the base station 105 may configure the UE to send one or more SRS transmissions in the two or more sTTIs. The operation of block 3115 may be performed according to reference Figures 1 to 11In some examples, aspects of the operation of block 3115 may be performed by reference to Figures 16 to 19 Describes the SRS configuration component implementation.

[0228] At block 3120, the base station 105 may send an aperiodic configuration of resources indicating the one or more SRS transmissions in an uplink grant to the UE. The operation of block 3120 may be performed according to reference Figures 1 to 11 In some examples, aspects of the operation of block 3120 may be performed by reference to Figures 16 to 19 The SRS configuration components described in this document are implemented in conjunction with the reference Fig.16 or the transmitter 1620 or 1720 described in 17, or reference Fig.19 Antenna 1940 and transceiver 1935 are depicted operating in cooperation.

[0229] Fig.32 A flow chart depicting a method 3200 for sounding reference signal transmission in low-latency wireless transmission according to aspects of the present disclosure is shown. The operations of the method 3200 may be implemented by a base station 105 or components thereof as described herein. For example, the operations of the method 3200 may be implemented by reference to Figures 16 to 19 The base station sTTI manager described herein is executed. In some examples, the base station 105 may execute a code set to control the functional elements of the device to perform the functions described below. Additionally or alternatively, the base station 105 may use dedicated hardware to perform aspects of the functions described below.

[0230] At block 3205, the base station 105 may identify a set of sTTIs for uplink transmission of the first wireless service that are within a subframe time boundary of a subframe of the second service. The operation of block 3205 may be performed according to reference Figures 1 to 11 In some examples, aspects of the operation of block 3205 may be performed by reference to Figures 16 to 19 Describes the implementation of the sTTI identification component.

[0231] At block 3210, the base station 105 may identify two or more sTTIs in the sTTI set for transmitting SRS transmissions within the subframe time boundary. The operation of block 3210 may be based on reference Figures 1 to 11 In some examples, aspects of the operation of block 3210 may be performed by reference to Figures 16 to 19 Describes the SRS identification component implementation.

[0232] At block 3215, the base station 105 may configure the UE to send one or more SRS transmissions in the two or more sTTIs. The operation of block 3215 may be performed according to reference Figures 1 to 11In some examples, aspects of the operation of block 3215 may be performed by reference to Figures 16 to 19 Describes the SRS configuration component implementation.

[0233] At block 3220, the base station 105 may send a downlink grant to the UE indicating that an uplink control channel transmission is to be sent and that the one or more SRS transmissions are to be sent. The operation of block 3220 may be based on reference Figures 1 to 11 In some examples, aspects of the operation of block 3220 may be performed by reference to Figures 16 to 19 The SRS configuration components described in this document are implemented in conjunction with the reference Fig.16 or the transmitter 1620 or 1720 described in 17, or reference Fig.19 Antenna 1940 and transceiver 1935 are depicted operating in cooperation.

[0234] Fig.33 A flow chart depicting a method 3300 for sounding reference signal transmission in low-latency wireless transmission according to aspects of the present disclosure is shown. The operations of the method 3300 may be implemented by a base station 105 or components thereof as described herein. For example, the operations of the method 3300 may be implemented by reference to Figures 16 to 19 The base station sTTI manager described herein is executed. In some examples, the base station 105 may execute a code set to control the functional elements of the device to perform the functions described below. Additionally or alternatively, the base station 105 may use dedicated hardware to perform aspects of the functions described below.

[0235] At block 3305, the base station 105 may identify a set of sTTIs for uplink transmission of the first wireless service that are within a subframe time boundary of a subframe of the second service. The operation of block 3305 may be performed according to reference Figures 1 to 11 In some examples, aspects of the operation of block 3305 may be performed by reference to Figures 16 to 19 Describes the implementation of the sTTI identification component.

[0236] At block 3310, the base station 105 may identify two or more sTTIs in the sTTI set for transmitting SRS transmissions within the subframe time boundary. The operation of block 3310 may be based on reference Figures 1 to 11 In some examples, aspects of the operation of block 3310 may be performed by reference to Figures 16 to 19 Describes the SRS identification component implementation.

[0237] At block 3315, the base station 105 may send configuration information indicating resources for periodic SRS transmission. The operation of block 3315 may be based on reference Figures 1 to 11In some examples, aspects of the operation of block 3315 may be performed by reference to Figures 16 to 19 The SRS configuration components described in this document are implemented in conjunction with the reference Fig.16 or the transmitter 1620 or 1720 described in 17, or reference Fig.19 Antenna 1940 and transceiver 1935 are depicted operating in cooperation.

[0238] Fig.34 A flow chart depicting a method 3400 for sounding reference signal transmission in low-latency wireless transmission according to aspects of the present disclosure is shown. The operations of the method 3400 may be implemented by a base station 105 or components thereof as described herein. For example, the operations of the method 3400 may be implemented by a base station 105 or components thereof as described herein. Figures 16 to 19 The base station sTTI manager described herein is executed. In some examples, the base station 105 may execute a code set to control the functional elements of the device to perform the functions described below. Additionally or alternatively, the base station 105 may use dedicated hardware to perform aspects of the functions described below.

[0239] At block 3405, the base station 105 may identify a set of sTTIs for uplink transmission of the first wireless service that are within a subframe time boundary of a subframe of the second service. The operation of block 3405 may be performed according to reference Figures 1 to 11 In some examples, aspects of the operation of block 3405 may be performed by reference to Figures 16 to 19 Describes the implementation of the sTTI identification component.

[0240] At block 3410, the base station 105 may identify two or more sTTIs in the sTTI set for transmitting SRS transmissions within the subframe time boundary. The operation of block 3410 may be based on reference Figures 1 to 11 In some examples, aspects of the operation of block 3410 may be performed by reference to Figures 16 to 19 Describes the SRS identification component implementation.

[0241] At block 3415, the base station 105 may configure the UE to multiplex the DMRS with the first SRS transmission in the first symbol. The operation of block 3415 may be based on reference Figures 1 to 11 In some examples, aspects of the operation of block 3415 may be performed by reference to Figures 16 to 19 Describes the implementation of a reusable component.

[0242] At block 3420, the base station 105 may receive the DMRS in a first interlace of a first symbol. The operation of block 3420 may be based on reference Figures 1 to 11 In some examples, aspects of the operation of block 3420 may be performed by reference to Figures 16 to 19The described reuse component is implemented, which can be used with reference Fig.16 or the receiver 1610 or 1710 described in 17, or reference Fig.19 Antenna 1940 and transceiver 1935 are depicted operating in cooperation.

[0243] At 3425, the base station 105 may receive the first SRS transmission in the second interlace of the first symbol. The operation of block 3425 may be performed according to reference Figures 1 to 11 In some examples, aspects of the operation of block 3425 may be performed by reference to Figures 16 to 19 The described reuse component is implemented, which can be used with reference Fig.16 or the receiver 1610 or 1710 described in 17, or reference Fig.19 Antenna 1940 and transceiver 1935 are depicted operating in cooperation.

[0244] Fig.35 A flow chart depicting a method 3500 for sounding reference signal transmission in low-latency wireless transmission according to aspects of the present disclosure is shown. The operations of the method 3500 may be implemented by a base station 105 or components thereof as described herein. For example, the operations of the method 3500 may be implemented by reference to Figures 16 to 19 The base station sTTI manager described herein is executed. In some examples, the base station 105 may execute a code set to control the functional elements of the device to perform the functions described below. Additionally or alternatively, the base station 105 may use dedicated hardware to perform aspects of the functions described below.

[0245] At block 3505, the base station 105 may identify a set of sTTIs for uplink transmission of the first wireless service that are within a subframe time boundary of a subframe of the second service. The operation of block 3505 may be performed according to reference Figures 1 to 11 In some examples, aspects of the operation of block 3505 may be described by reference to Figures 16 to 19 Describes the implementation of the sTTI identification component.

[0246] At block 3510, the base station 105 may identify two or more sTTIs in the sTTI set for transmitting SRS transmissions within the subframe time boundary. The operation of block 3510 may be based on reference Figures 1 to 11 In some examples, aspects of the operation of block 3510 may be performed by reference to Figures 16 to 19 Describes the SRS identification component implementation.

[0247] At block 3515, the base station 105 may configure the UE to multiplex the DMRS with the first SRS transmission in the first symbol. The operation of block 3515 may be based on reference Figures 1 to 11In some examples, aspects of the operation of block 3515 may be performed by reference to Figures 16 to 19 Describes the implementation of a reusable component.

[0248] At block 3520, the base station 105 may receive the DMRS in a first interlace of a first symbol using a first cyclic shift. The operation of block 3520 may be based on reference Figures 1 to 11 In some examples, aspects of the operation of block 3520 may be performed by reference to Figures 16 to 19 The described reuse component is implemented, which can be used with reference Fig.16 or the receiver 1610 or 1710 described in 17, or reference Fig.19 Antenna 1940 and transceiver 1935 are depicted operating in cooperation.

[0249] At 3525, the base station 105 may receive the first SRS transmission in the first interlace of the first symbol using a second cyclic shift. The operation of block 3525 may be based on reference Figures 1 to 11 In some examples, aspects of the operation of block 3525 may be performed by reference to Figures 16 to 19 The described reuse component is implemented, which can be used with reference Fig.16 or the receiver 1610 or 1710 described in 17, or reference Fig.19 Antenna 1940 and transceiver 1935 are depicted operating in cooperation.

[0250] Fig.36 A flow chart depicting a method 3600 for sounding reference signal transmission in low-latency wireless transmission according to aspects of the present disclosure is shown. The operations of the method 3600 may be implemented by a base station 105 or components thereof as described herein. For example, the operations of the method 3600 may be implemented by a base station 105 or components thereof as described herein. Figures 16 to 19 The base station sTTI manager described herein is executed. In some examples, the base station 105 may execute a code set to control the functional elements of the device to perform the functions described below. Additionally or alternatively, the base station 105 may use dedicated hardware to perform aspects of the functions described below.

[0251] At block 3605, the base station 105 may identify a set of sTTIs for uplink transmission of the first wireless service that are within a subframe time boundary of a subframe of the second service. The operation of block 3605 may be performed according to reference Figures 1 to 11 In some examples, aspects of the operation of block 3605 may be performed by reference to Figures 16 to 19 Describes the implementation of the sTTI identification component.

[0252] At block 3610, the base station 105 may identify two or more sTTIs in the sTTI set for transmitting SRS transmissions within the subframe time boundary. The operation of block 3610 may be based on reference Figures 1 to 11 In some examples, aspects of the operation of block 3610 may be performed by reference to Figures 16 to 19 Describes the SRS identification component implementation.

[0253] At block 3615, the base station 105 may configure the UE to multiplex the DMRS with the first SRS transmission in the first symbol. The operation of block 3615 may be based on reference Figures 1 to 11 In some examples, aspects of the operation of block 3615 can be performed by reference to Figures 16 to 19 Describes the implementation of a reusable component.

[0254] At block 3620, the base station 105 may receive the DMRS using a first set of antenna ports. The operation of block 3620 may be performed according to reference Figures 1 to 11 In some examples, aspects of the operation of block 3620 may be performed by reference to Figures 16 to 19 The described reuse component is implemented, which can be used with reference Fig.16 or the receiver 1610 or 1710 described in 17, or reference Fig.19 Antenna 1940 and transceiver 1935 are depicted operating in cooperation.

[0255] At 3625, the base station 105 may receive the first SRS transmission using a second set of antenna ports that is different from the first set of antenna ports. The operation of block 3625 may be performed according to reference Figures 1 to 11 In some examples, aspects of the operation of block 3625 may be performed by reference to Figures 16 to 19 The described reuse component is implemented, which can be used with reference Fig.16 or the receiver 1610 or 1710 described in 17, or reference Fig.19 Antenna 1940 and transceiver 1935 are depicted operating in cooperation.

[0256] It should be noted that the methods described above describe possible implementations, and the operations and steps may be rearranged or modified, and other implementations are possible. Furthermore, aspects from two or more methods may be combined.

[0257] The technology described in this application can be used in various wireless communication systems, such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal frequency division multiple access (OFDMA), single carrier frequency division multiple access (SC-FDMA) and other systems. The terms "system" and "network" are usually used interchangeably. Code division multiple access (CDMA) systems can implement radio technologies such as CDMA2000, Universal Terrestrial Radio Access (UTRA), etc. CDMA 2000 includes IS-2000, IS-95 and IS-856 standards. IS-2000 versions can be generally referred to as CDMA 2000 1X, 1X, etc. IS-856 (TIA-856) can be generally referred to as CDMA 20001xEV-DO, High Speed ​​Packet Data (HRPD), etc. UTRA includes broadband CDMA (W-CDMA) and other variations of CDMA. Time division multiple access (TDMA) systems can implement wireless technologies such as Global System for Mobile Communications (GSM).

[0258] Orthogonal frequency division multiple access (OFDMA) systems can implement wireless technologies such as ultra mobile broadband (UMB), evolved UTRA (E-UTRA), Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM, etc. UTRA and E-UTRA are part of Universal Mobile Telecommunications System (UMTS). 3GPP Long Term Evolution (LTE) and Advanced LTE (LTE-A) are new versions of Universal Mobile Telecommunications System (UMTS) using E-UTRA, and Global System for Mobile Communications (GSM) is described in documents from an organization named "3rd Generation Partnership Project" (3GPP). CDMA 2000 and UMB are described in documents from an organization named "3rd Generation Partnership Project 2" (3GPP2). The technology described in this application can be used for the systems and wireless technologies mentioned above as well as other systems and wireless technologies. Although aspects of LTE or NR systems may be described for illustration purposes, and LTE or NR terminology may be used in much of this specification, the techniques described herein are applicable beyond LTE or NR applications.

[0259] In LTE / LTE-A networks, including those described in this application, the term evolved node (eNB) may be generally used to describe a base station. The wireless communication system or systems described in this application may include heterogeneous LTE / LTE-A or NR networks, in which different types of evolved Node Bs (eNBs) provide coverage for various geographic areas. For example, each eNB, gNB, or base station may provide communication coverage for a macro cell, a small cell, or other types of cells. The term "cell" may be used to describe a base station, a carrier or component carrier associated with a base station, or a coverage area (e.g., sector, etc.) of a carrier or base station, depending on the context.

[0260] A base station may include or may be referred to by those skilled in the art as a base transceiver station, a wireless base station, an access point, a wireless transceiver, a Node B, an eNB, a gNB, a Home Node B, a Home eNodeB, or some other applicable term. The geographic coverage area of ​​a base station may be divided into sectors that constitute a portion of the coverage area. The wireless communication system or systems described in the present application may include different types of base stations (e.g., macro cells or small cell base stations). The UE described in the present application is capable of communicating with various types of base stations and network devices, including macro eNBs, small cell eNBs, gNBs, relay base stations, and the like. Different technologies may have overlapping geographic coverage areas.

[0261] A macro cell generally covers a relatively large geographic area (e.g., a radius of several thousand kilometers) and may allow unrestricted access to UEs with service subscriptions to the network provider. A small cell is a low-power base station compared to a macro cell, which may operate in the same or different frequency bands (e.g., licensed, unlicensed, etc.) as the macro cell. Small cells may include pico cells, femto cells, and micro cells according to various examples. For example, a pico cell may cover a smaller geographic area and may allow unrestricted access to UEs with service subscriptions to the network provider. A femto cell may also cover a smaller geographic area (e.g., a home) and may allow restricted access to UEs associated with the femto cell (e.g., UEs in a closed subscriber group (CSG), UEs of users in a home, etc.). An eNB of a macro cell may be referred to as a macro eNB. An eNB of a small cell may be referred to as a small cell eNB, a pico eNB, a femto eNB, or a home eNB. An eNB may support one or more (e.g., two, three, four, etc.) cells (e.g., component carriers).

[0262] The wireless communication systems or systems described in this application may support synchronous or asynchronous operation. For synchronous operation, the base stations may have similar frame timing, and transmissions from different base stations may be approximately aligned in time. For asynchronous operation, the base stations may have different frame timing, and transmissions from different base stations may not be aligned in time. The techniques described in this application may be used for synchronous or asynchronous operation.

[0263] Downlink transmissions described in this application may also be referred to as forward link transmissions, and uplink transmissions may also be referred to as reverse link transmissions. Each communication link described in this application—including, for example, Figure 1 and 2 The wireless communication system 100 may include one or more carriers, where each carrier may be a signal composed of multiple subcarriers (eg, waveform signals of different frequencies).

[0264] The detailed description presented above in conjunction with the accompanying drawings describes example configurations and does not represent all examples that can be implemented or within the scope of the claims. The term "exemplary" used in this application means "used as an example, instance, or illustration", and is not "preferable" or "more advantageous" than other examples. The specification includes specific details for the purpose of providing an understanding of the described techniques. However, these techniques can be practiced without these specific details. In some instances, well-known structures and devices are shown in block diagram form to avoid obscuring the concepts of the described examples.

[0265] In the drawings, similar components or features may have the same reference label. In addition, various components of the same type may be distinguished by a dash and a secondary label following the reference label to distinguish between the similar components. If only a primary reference label is used in the specification, the description applies to any of the similar components having the same primary reference label regardless of the secondary reference label.

[0266] The information and signals described in this application may be represented using any of a variety of different techniques and methods. For example, the data, instructions, commands, information, signals, bits, symbols, and chips mentioned throughout the above description may be represented by voltage, current, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0267] The various exemplary blocks and modules described in conjunction with the present disclosure may be implemented or executed using a general purpose processor, DSP, ASIC, FPGA or other programmable logic device, discrete gate or transistor logic device, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, or the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, a combination of one or more microprocessors and a DSP core, or any other such structure).

[0268] The functions described in this application can be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions can be stored on a computer-readable medium or transmitted as one or more instructions or codes. Other examples and implementations are also within the scope of the present invention and the appended claims. For example, due to the characteristics of software, the functions described above can be implemented with software executed by a processor, hardware, firmware, hard coding, or any combination of these. The characteristics of implementing the functions can also be physically located in various locations, including distribution so that the various parts of the functions are implemented in different physical locations. In addition, as used in this application and included in the claims, the "or" used in the list of items (e.g., a list of items beginning with phrases such as "at least one" or "one or more") indicates a separate list, such as the list "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). In addition, as used in this application, the phrase "based on" should not be interpreted as a reference to a closed set of conditions. For example, the example steps described as "based on condition A" can be based on both condition A and condition B without departing from the scope of the present disclosure. In other words, as used in this application, the phrase "based on" should be interpreted in the same manner as the phrase "based at least in part on."

[0269] Computer readable medium includes both permanent computer storage medium and communication medium, and communication medium includes any medium that helps computer program transfer from one location to another.Permanent storage medium can be any available medium accessible to general-purpose computer or special-purpose computer.For example, but not limited to, permanent computer readable medium can include RAM, ROM, electrically erasable programmable read-only memory (EEPROM), compact disk (CD) ROM or other optical disk storage, disk storage or other magnetic storage device, or can be used for loading or storing expected program code in the form of instruction or data structure, and by general or special-purpose computer, or any other permanent medium accessed by general or special-purpose processor.And, any connection is appropriately referred to as computer readable medium.For example, if the software uses coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL) or wireless technology such as infrared, radio and microwave to send from website, server or other remote source, then the coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL) or wireless technology such as infrared, radio and microwave are included in the definition of medium. Disks and optical disks used in this application include CDs, laserdiscs, optical disks, digital video disks (DVDs), floppy disks, and blue-ray disks, wherein disks generally reproduce data magnetically, while optical disks reproduce data optically with lasers. Combinations of the above may also be included within the scope of computer-readable media.

[0270] The description in this application is provided to enable those skilled in the art to implement or use the present disclosure. Various modifications to the present disclosure will be apparent to those skilled in the art, and the general principles defined in this application may also be applicable to other variations without departing from the scope of the present disclosure. Therefore, the present disclosure is not limited to the examples and designs described in this application, but is consistent with the broadest range of principles and novel features disclosed in this application.

Claims

1. A method for wireless communication, comprising: identifying a first set of two or more consecutive orthogonal frequency division multiplexing (OFDM) symbols in a subframe for sounding reference signal (SRS) transmission; as well as transmitting one or more SRS using a first set of the two or more consecutive OFDM symbols, The frequency resources of the two or more consecutive OFDM symbols are selected to provide frequency hopping for frequency diversity.

2. The method of claim 1, further comprising: identifying a second set of two or more consecutive OFDM symbols in the subframe for SRS transmission; as well as The one or more SRSs are transmitted using the first set of the two or more consecutive OFDM symbols and the second set of the two or more consecutive OFDM symbols.

3. The method of claim 1, wherein the two or more consecutive OFDM symbols are two or three consecutive OFDM symbols.

4. An apparatus for wireless communication, comprising: means for identifying a first set of two or more consecutive orthogonal frequency division multiplexing (OFDM) symbols in a subframe for sounding reference signal (SRS) transmission; as well as means for transmitting one or more SRS using the first set of two or more consecutive OFDM symbols, The frequency resources of the two or more consecutive OFDM symbols are selected to provide frequency hopping for frequency diversity.

5. The apparatus of claim 4, further comprising: means for identifying a second set of two or more consecutive OFDM symbols in the subframe for SRS transmission; as well as Means for transmitting the one or more SRS using the first set of the two or more consecutive OFDM symbols and the second set of the two or more consecutive OFDM symbols. The apparatus of claim 4 , wherein the two or more consecutive OFDM symbols are two or three consecutive OFDM symbols.

7. A computer readable medium having a computer program stored thereon, which, when executed by a processor, causes the processor to perform operations for wireless communication, the operations comprising: identifying a first set of two or more consecutive orthogonal frequency division multiplexing (OFDM) symbols in a subframe for sounding reference signal (SRS) transmission; as well as transmitting one or more SRS using a first set of the two or more consecutive OFDM symbols, The frequency resources of the two or more consecutive OFDM symbols are selected to provide frequency hopping for frequency diversity.

8. The computer readable medium of claim 7, wherein said operations further comprise: identifying a second set of two or more consecutive OFDM symbols in the subframe for SRS transmission; as well as The one or more SRSs are transmitted using the first set of the two or more consecutive OFDM symbols and the second set of the two or more consecutive OFDM symbols.

9. The computer-readable medium of claim 7, wherein the two or more consecutive OFDM symbols are two or three consecutive OFDM symbols.

10. An apparatus for wireless communication, comprising: Memory; as well as A processor, connected to the memory, configured to perform an operation, wherein the operation includes: identifying a first set of two or more consecutive orthogonal frequency division multiplexing (OFDM) symbols in a subframe for sounding reference signal (SRS) transmission; and transmitting one or more SRS using a first set of the two or more consecutive OFDM symbols, The frequency resources of the two or more consecutive OFDM symbols are selected to provide frequency hopping for frequency diversity.

11. The apparatus of claim 10, wherein the operations further comprise: identifying a second set of two or more consecutive OFDM symbols in the subframe for SRS transmission; as well as The one or more SRSs are transmitted using the first set of the two or more consecutive OFDM symbols and the second set of the two or more consecutive OFDM symbols.

12. The apparatus of claim 10, wherein the two or more consecutive OFDM symbols are two or three consecutive OFDM symbols.

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