WO2017135988A1

WO2017135988A1 - Uplink dm-rs transmission for pusch transmissions with shortened tti

Info

Publication number: WO2017135988A1
Application number: PCT/US2016/038090
Authority: WO
Inventors: Alexei Davydov; Christian Ibars Casas; Hong He; Seunghee Han
Original assignee: Intel IP Corporation
Priority date: 2016-02-05
Filing date: 2016-06-17
Publication date: 2017-08-10
Also published as: CN108702269B; CN108702269A

Abstract

The present disclosure provides an uplink demodulation reference signal (DM-RS) transmission. Generating the DM-RS transmission includes receiving, from a serving cell, physical uplink shared channel (PUSCH) parameters including a position of the DM-RS transmission in a time domain and a frequency domain, wherein the DM-RS transmission, in the frequency domain, is transmitted in a pattern that is repeated over p subcarriers within a PUSCH resource allocation. Generating the DM-RS transmission also includes generating a PUSCH transmission in accordance with the PUSCH parameters.

Description

UPLINK DM-RS TRANSMISSION FOR PUSCH TRANSMISSIONS WITH

SHORTENED TTI

Related Applications

[0001] This application is a non-provisional of U.S. Provisional Patent Application No. 62/291 ,634, filed February 5, 2016, which is incorporated by reference herein in its entirety.

Technical Field

[0002] The present disclosure relates to an uplink demodulation reference signal (DM-RS) transmission. In particular, the present disclosure relates to an uplink DM- RS with a shortened transmission time interval (TTI).

Background

[0003] Mobile communication has evolved significantly from early voice systems to today's highly sophisticated and integrated communication platform. Low latency is a key requirement in the development of LTE. Due to properties of internet protocols, lower latency over the wireless interface may be critical to realize higher data rates. With the increasing data rates in LTE over a past couple of releases, it is important to ensure that the achievable latency evolves in a similar manner. In addition, lower latency may also enable support for new applications. Some of the envisioned applications, such as traffic safety/control and control of critical infrastructure, and industry processes, may require very low latency. Consequently, with these two aspects in mind, 3GPP will, in release 14 and beyond, standardize enhancements providing reduced latency. Examples of technologies considered in this work are instant uplink access, transmission time interval (TTI) shortening, and reduced processing time in terminals and base stations. The enhancement would be applicable to both downlink and uplink. [0004] An uplink DM-RS transmission is used to estimate uplink channel quality. Estimating uplink channel quality may allow an evolved node b (eNodeB) to make decisions for resource allocation for uplink transmissions, link adaptation, anddecode transmitted data from user equipment (UE).

Brief Description of the Drawings

[0005] FIG. 1 is a diagram of an up link (UL) schedule according to one embodiment.

[0006] FIG. 2 is a diagram of a UL schedule according to one embodiment.

[0007] FIG. 3 is a diagram of a UL schedule according to one embodiment.

[0008] FIG. 4 is a block diagram illustrating electronic device circuitry that may be eNodeB circuitry, user equipment (UE) circuitry, network node circuitry, or some other type of circuitry according to one embodiment.

[0009] FIG. 5 is a block diagram illustrating a method for a UL schedule according to one embodiment.

[0010] FIG. 6 is a block diagram illustrating a method for a UL schedule according to one embodiment.

[0011] FIG. 7 is a block diagram illustrating a method for a UL schedule according to one embodiment.

[0012] FIG. 8 is a block diagram illustrating components of a UE device according to one embodiment.

[0013] FIG. 9 is a block diagram illustrating components according to some embodiments.

Detailed Description of Preferred Embodiments

[0014] Wireless mobile communication technology uses various standards and protocols to generate and/or transmit data between a base station and a wireless communication device. Wireless communication system standards and protocols can include, for example, a 3rd Generation Partnership Project (3GPP) long term evolution (LTE); the Institute of Electrical and Electronics Engineers (IEEE) 802.16 standard, which is commonly known to industry groups as worldwide interoperability for microwave access (WiMAX); and the IEEE 802.1 1 standard, which is commonly known to industry groups as Wireless Local Area Network (WLAN) or Wi-Fi. In 3GPP radio access networks (RANs) in LTE systems, a base station may include Evolved Universal Terrestrial Radio Access Network (E-UTRAN) Node B (also commonly denoted as evolved Node B, enhanced Node B, eNodeB, or eNB) and/or Radio Network Controllers (RNCs) in the E-UTRAN, which communicate with a wireless communication device, known as user equipment (UE). In LTE networks, the E-UTRAN may include a plurality of eNodeBs and may communicate with the plurality of UEs. LTE networks include a radio access technology (RAT) and core radio network architecture that can provide high data rate, low latency, packet optimization, and improved system capacity and coverage.

[0015] Uplink subframes with normal TTI comprise 14 single-carrier frequency- division multiple access (SC-FDMA) symbols, where two SC-FDMA symbols of an uplink subframe are allocated for transmission of the DM-RS and the remaining 12 SC-FDMA symbols for physical uplink shared channel (PUSCH) transmissions. In some cases, the last SC-FDMA symbol of the uplink subframe may be also used for the transmission of sounding reference signals (SRS).

[0016] The PUSCH for LTE is based on an SC-FDMA symbol, where each symbol is a discrete fourier transform (DFT) precoded in the frequency domain prior to subcarrier modulation. The DM-RSs are used to facilitate channel estimation at the serving cell (e.g., eNodeB). The uplink DM-RSs in LTE are transmitted in the middle of each slot. For example, uplink DM-RSs can be transmitted on the SC- FDMA symbols with an index equal to 3 and 10 and modulated using Zadoff-chu sequence (e.g., base sequence) except for the small resource allocation sizes of 1 or 2 RBs.

[0017] The SC-FDMA symbols for the DM-RS can be shared by multiple UEs. The SC-FDMA symbols can be shared to, for example, support multi-user multiple- input and multiple-output (MUMIMO) technologies. To minimize interference between the DM-RS signals of different UEs, different cyclic shifts of the base sequence can be used, which may be the equivalent of applying discrete fourier transformation (DFT) orthogonal cover codes on top of a Zadoff-chu sequence. It should be noted that orthogonal multiplexing of the DM-RS may be only possible when the DM-RS sequences have the same lengths or the resource allocation sizes of UEs are the same and the DM-RS sequences fully overlap with each other.

Support for orthogonal DM-RS multiplexing for a PUSCH with not aligned resource allocations is provided by using time domain orthogonal cover code, which may be applied across two DM-RSs of one uplink subframe.

[0018] In a number of embodiments, a new uplink DM-RS structure is provided. In the one embodiment, the DM-RS is placed in the beginning of each slot of the uplink subframe to facilitate early channel estimation for PUSCH processing. In some embodiments, the DM-RS symbol is shared by different UEs with a frequency division multiplexing (FDM) based multiplexing (e.g., by using different combs). As used herein, combs define ...

[0019] For PUSCH with shortened TTI, the problem of DM-RS overhead should be also considered. The corresponding overhead can be reduced by sharing the same SC-FDMA symbol allocated for the DM-RS transmission between different UEs. For example, similar to the previous approaches for the DM-RS, different cyclic shifts can be used to provide orthogonal multiplexing of the DM-RS of different UEs. This approach, however, may not support PUSCH resource allocations of different sizes. The DM-RS for PUSCH resource allocations of different sizes may be based on different base sequences. The DM-RS multiplexing of different UEs may not be orthogonal to each other even if different cyclic shifts are applied on top of the base sequences.

[0020] The conventional time division multiplexing (TDM) based on orthogonal cover code (OCC) multiplexing may not be efficient to support PUSCH resource allocations of different sizes due to additional latency required to jointly process two DM-RS symbols. The SC-FDMA symbol(s) allocated for DM-RS transmission may be shared by different UEs. The orthogonal sharing of DM-RS is provided by using FDM multiplexing (e.g., comb). For example, the DM-RS symbols with FDM structure may be placed in legacy positions (e.g., in SC-FDMA symbols with indices 3 and 10).

[0021] The first DM-RS (SC-FDMA symbol with an index equal to 3) may be used for UEs scheduled for a PUSCH transmission in the first slot (SC-FDMA symbols 0-6 of uplink subframe with normal TTI). The second DM-RS (SC-FDMA symbol with index 10) may be used for the UEs scheduled for a PUSCH transmission in the second slot (SC-FDMA symbols 7-13 of uplink subframe with normal TTI). FIG. 1 provides an example where the comb 4 is assumed for FDM multiplexing of different UEs. Embodiments are not limited with respect to use of comb 4, and other combs may be used as well.

[0022] To facilitate demodulation of the PUSCH with shortened TTI, the DM-RS in time domain may be transmitted on the SC-FDMA symbols, which may be nearby or before SC-FDMA symbols of the PUSCH transmission. As used herein, nearby can denote a numerical proximity as it relates to an index of the SC-FDMA symbols. For example, if a PUSCH transmission is transmitted in an indices equal to 4 and 5 of the SC-FDMA symbols, then the DM-RS transmitted in an index equal to 3 can be transmitted near to the PUSCH transmission. Other embodiments may include shifting DM-RS symbols to the beginning of each slot of the uplink subframe with normal TTIs to facilitate early channel estimation processing for the UE receiving PUSCH with shortened TTI (e.g., DM-RS for PUSCH with shortened TTI may be transmitted on the non-legacy SC-FDMA symbols such as SC-FDMA symbols with an index equal to 0 and/or 7). For example, the UEs scheduled for a PUSCH transmission in the first slot (e.g., SC-FDMA symbols with an index equal to 0 to 6 of uplink subframe with normal TTI) can utilize the first DM-RS (e.g., SC-FDMA symbol with an index equal to 0). For example, the UE scheduled for a PUSCH

transmission in the second slot (e.g., SC-FDMA symbols with an index equal to 7 to 13 of an uplink subframe with a normal TTI) can utilize the second DM-RS (e.g., SC- FDMA symbol with an index equal to 7). The example of this embodiment is illustrated in FIG. 2, where comb 4 is assumed for FDM multiplexing of different UEs. Embodiments are not limited with respect to use of comb 4, and other combs may be used as well.

[0023] In another embodiment, more than two SC-FDMA symbols of the uplink subframe may be used for the transmission of the DM-RS. A non-limiting example of an uplink subframe with four DM-RS symbols is shown in FIG. 3, where comb 2 is assumed for FDM multiplexing of different UEs. Embodiments are not limited with respect to use of comb 2, and other combs may be used as well.

[0024] Reference is now made to the figures, in which like reference numerals refer to like elements. For clarity, the first digit of a reference numeral indicates the figure number in which the corresponding element is first used. In the following description, numerous specific details are provided for a thorough understanding of the embodiments disclosed herein. However, those skilled in the art will recognize that the embodiments described herein can be practiced without one or more of the specific details, or with other methods, components, or materials. Further, in some cases, well-known structures, materials, or operations are not shown or described in detail in order to avoid obscuring aspects of the embodiments. Furthermore, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. [0025] FIG. 1 is a diagram of an uplink (UL) schedule according to one

embodiment. FIG. 1 includes an uplink subframe 100 in a time domain that is defined utilizing SC-FDMA symbols with an indices 102 and a frequency domain that is defined utilizing subcarriers 104.

[0026] The indices 102 and/or the subcarriers 104 can be referred to herein as PUSCH resource allocations. For example, a PUSCH resource allocation can describe a position of a DM-RS transmission with regard to PUSCH parameters that coincide with the indices 102 and/or the subcarriers 104.

[0027] A plurality of PUSCH transmissions are defined in the uplink subframe 100. For example, the uplink subframe 100 defines PUSCH transmissions 106-1 , 106-2, 106-3, 106-4, 106-5, 106-6, and 106-7, which are referred to herein as PUSCH transmissions 106. The PUSCH transmission 106-1 is transmitted on the SC-FDMA symbols with an indices equal to 12 and 13. The PUSCH transmission 106-2 is transmitted on the SC-FDMA symbols with an indices equal to 9 and 1 1 . The PUSCH transmission 106-3 is transmitted on the SC-FDMA symbols with an indices equal to 7 and 8. The PUSCH transmission 106-4 is transmitted on the SC- FDMA symbols with an indices equal to 5 and 6. The PUSCH transmission 106-5 is transmitted on the SC-FDMA symbols with an indices equal to 2 and 4. The PUSCH transmission 106-6 is also transmitted on the SC-FDMA symbols with an indices equal to 2 and 4. The PUSCH transmission 106-7 is transmitted on the SC-FDMA symbols with an indices equal to 0 and 1 . The PUSCH transmissions 106-5 and 106-6 can be transmitted on the same SC-FDMA symbols (e.g., SC-FDMA symbols with an indices equal to 2 and 4) because the PUSCH transmissions 106-5 and 106- 6 are transmitted on different subcarriers from the subcarriers 104.

[0028] The PUSCH transmissions 106 can be transmitted by a plurality of UEs. For example, each of the PUSCH transmissions 106 can be transmitted by a different UE from a plurality of UEs.

[0029] Each of the PUSCH transmissions 106 can be associated with a DM-RS transmission from the DM-RS transmissions 108-1 , 108-2, 108-3, 108-4, 108-5, 108- 6, and 108-7, referred to herein as DM-RS transmissions 108. For example, the PUSCH transmission 106-1 is associated with the DM-RS transmission 108-1 . The PUSCH transmission 106-2 is associated with the DM-RS transmission 108-2. The PUSCH transmission 106-3 is associated with the DM-RS transmission 108-3. The PUSCH transmission 106-4 is associated with the DM-RS transmission 108-4. The PUSCH transmission 106-5 is associated with the DM-RS transmission 108-5. The PUSCH transmission 106-6 is associated with the DM-RS transmission 108-6. The PUSCH transmission 106-7 is associated with the DM-RS transmission 108-7.

[0030] An association between the PUSCH transmissions 106 and the DM-RS transmissions 108 can exist when a UE transmitted the PUSCH transmission and the DM-RS transmission. For example, a first UE transmitted the PUSCH

transmission 106-1 and the DM-RS transmission 108-1 , a second UE transmitted the PUSCH transmission 106-2 and the DM-RS transmission 108-2, a third UE transmitted the PUSCH transmission 106-3 and the DM-RS transmission 108-3, a fourth UE transmitted the PUSCH transmission 106-4 and the DM-RS transmission 108-4, a fifth UE transmitted the PUSCH transmission 106-5 and the DM-RS transmission 108-5, a sixth UE transmitted the PUSCH transmission 106-6 and the DM-RS transmission 108-6, and a seventh UE transmitted the PUSCH transmission 106-7 and the DM-RS transmission 108-7. As such, the DM-RS transmission 108-1 corresponds to the PUSCH transmission 106-1 , the DM-RS transmission 108-2 corresponds to the PUSCH transmission 106-2, the DM-RS transmission 108-3 corresponds to the PUSCH transmission 106-3, the DM-RS transmission 108-4 corresponds to the PUSCH transmission 106-4, the DM-RS transmission 108-5 corresponds to the PUSCH transmission 106-5, the DM-RS transmission 108-6 corresponds to the PUSCH transmission 106-6, and the DM-RS transmission 108-7 corresponds to the PUSCH transmission 106-7.

[0031] In the example provided in FIG. 1 , the DM-RS transmissions 108-1 , 108-2, and 108-3 are transmitted on the SC-FDMA symbols with an index equal to 10. The DM-RS transmissions 108-1 , 108-2, and 108-3 are transmitted on the SC-FDMA symbols with an index equal to 10 in response to the PUSCH transmissions 106-4, 106-5, 106-6, and 106-7 being transmitted on a second slot. The DM-RS

transmissions 108-4, 108-5, 108-6, and 108-7 are transmitted on the SC-FDMA symbols with an index equal to 3. The DM-RS transmissions 108-4, 108-5, 108-6, and 108-7 are transmitted on the SC-FDMA symbols with an index equal to 3 in response to the PUSCH transmissions 106-4, 106-5, 106-6, and 106-7 being transmitted on a first slot.

[0032] In a number of examples, the DM-RS transmissions 108 are transmitted on the subcarriers 104 which are also used to transmit the PUSCH transmissions 106. For example, the DM-RS transmission 108-1 is transmitted on a portion of the subcarriers 104 used to transmit the PUSCH transmission 106-1 , the DM-RS transmission 108-2 is transmitted on a portion of the subcarriers 104 used to transmit the PUSCH transmission 106-2, the DM-RS transmission 108-3 is transmitted on a portion of the subcarriers 104 used to transmit the PUSCH transmission 106-3, the DM-RS transmission 108-4 is transmitted on a portion of the subcarriers 104 used to transmit the PUSCH transmission 106-4, the DM-RS transmission 108-5 is

transmitted on a portion of the subcarriers 104 used to transmit the PUSCH transmission 106-5, the DM-RS transmission 108-6 is transmitted on a portion of the subcarriers 104 used to transmit the PUSCH transmission 106-6, and the DM-RS transmission 108-7 is transmitted on a portion of the subcarriers 104 used to transmit the PUSCH transmission 106-7.

[0033] In FIG. 1 , each of the DM-RS transmissions 108 are transmitted on every fourth subcarrier from the subcarriers 104. That is, the DM-RS transmissions 108 are transmitted in a pattern that is repeated over p subcarriers. In a number of examples, each of the DM-RS transmissions 108 can be transmitted on different combination of subcarriers from the subcarriers 104. For example, the DM-RS transmission 108 can be transmitted every third subcarrier. Transmitting and/or receiving the DM-RS transmissions 108 on specific subcarriers provides the ability to transmit and/or receive different DM-RS transmissions 108 on a same range of subcarriers. For example, a portion of the DM-RS transmissions 108-1 , 108-2, and 108-3 are transmitted on a same range of subcarriers.

[0034] In FIG. 1 , each of the PUSCH transmissions 106 corresponds to a DM-RS transmission transmitted on the single index from the indices 102. For example, the PUSCH transmission 106-2 corresponds to the DM-RS transmission 108-2

transmitted on a symbol with an index equal to 10. In different embodiments, each of the PUSCH transmissions 106 can correspond to a DM-RS transmission transmitted on multiple indices.

[0035] In some embodiments, the DM-RS transmissions 108 can be transmitted on different indices 102 and/or subcarriers 104 than those described in FIG. 1.

[0036] FIG. 2 is a diagram of a UL schedule according to one embodiment. FIG. 2 includes an uplink subframe 200 in a time domain that is defined utilizing SC- FDMA symbols with an indices 202 and a frequency domain that is defined utilizing subcarriers 204. The indices 202 and the subcarriers 204 are analogous to the indices 102 and the subcarriers 104 in FIG. 1 , respectively. FIG. 2 includes PUSCH transmissions 206-1 , 206-2, 206-3, 206-4, 206-5, 206-6, and 206-7 (e.g., referred to generally as PUSCH transmissions 206) which are analogous to PUSCH

transmissions 106-1 , 106-2, 106-3, 106-4, 106-5, 106-6, and 106-7 in FIG. 1. FIG. 2 also includes DM-RS transmissions 208-1 , 208-2, 208-3, 208-4, 208-5, 208-6, and 208-7 (e.g., referred to generally as DM-RS transmissions 208) which are analogous to DM-RS transmissions 108-1 , 108-2, 108-3, 108-4, 108-5, 108-6, and 108-7 in FIG. 1 .

[0037] In FIG. 2, the DM-RS transmissions 208-1 , 208-2, and 208-3 are

transmitted on an index with a value equal to 7 as compared to the DM-RS

transmissions 108-1 , 108-2, and 108-3 which are transmitted on an index with a value equal to 10 in FIG. 1 . The DM-RS transmissions 208-4, 208-5, 208-6, and 208-7 are transmitted on an index with a value equal to 0 as compared to the DM-RS transmissions 108-4, 108-5, 108-6, and 108-7 which are transmitted on an index with a value equal to 2 in FIG. 1 .

[0038] The DM-RS transmission 208-1 corresponds to the PUSCH transmission 206-1 , the DM-RS transmission 208-2 corresponds to the PUSCH transmission 206- 2, the DM-RS transmission 208-3 corresponds to the PUSCH transmission 206-3, the DM-RS transmission 208-4 corresponds to the PUSCH transmission 206-4, the DM-RS transmission 208-5 corresponds to the PUSCH transmission 206-5, the DM- RS transmission 208-6 corresponds to the PUSCH transmission 206-6, and the DM- RS transmission 208-7 corresponds to the PUSCH transmission 206-7.

[0039] FIG. 2 shows that the DM-RS transmissions 208 can be transmitted on any index. For example, although the DM-RS transmissions 208-1 , 208-2, and 208- 3 are shown as being transmitted on index 7 in FIG. 2, the DM-RS transmissions 208-1 208-2, and 208-3 can be transmitted in any of the indices 7 to 13. For example, the DM-RS transmissions 208-1 , 208-2, and 208-3 can be transmitted in any one of the indices 7 to 13 or the DM-RS transmissions 208-1 , 208-2, and 208-3 can be transmitted in any combination of the indices 7 to 13. That is, a PUSCH transmission on a second slot of the subframe 200 can be associated with a DM-RS transmission that is transmitted on the SC-FDMA symbols with an index having a value of 7 to 13. For example, a PUSCH transmission on a second slot of the uplink subframe 200 can be associated with a DM-RS transmission that is transmitted on the SC-FDMA symbols with an index equal to 7 and 9. [0040] FIG. 3 is a diagram of a UL schedule according to one embodiment. FIG. 3 includes an uplink subframe 300 in a time domain that is defined utilizing SC- FDMA symbols with an indices 302 and a frequency domain that is defined utilizing subcarriers 304. The indices 302 and the subcarriers 304 are analogous to the indices 102 and 202 and the subcarriers 104 and 204 in FIGs. 1 and 2, respectively. FIG. 3 includes PUSCH transmissions 306-1 , 306-2, 306-3, 306-4, 306-5, and 306-6 (e.g., referred to generally as PUSCH transmissions 306) which are analogous to PUSCH transmissions 106-1 , 106-2, 106-3, 106-4, 106-5, 106-6, and 106-7, and 206-1 , 206-2, 206-3, 206-4, 206-5, 206-6, and 206-7 in FIGs. 1 and 2. FIG. 3 also includes DM-RS transmissions 308-1 , 308-2, 308-3, 308-4, 308-5, and 308-6 (e.g., referred to generally as DM-RS transmissions 308) which are analogous to DM-RS transmissions 108-1 , 108-2, 108-3, 108-4, 108-5, 108-6, and 108-7 and 208-1 , 208- 2, 208-3, 208-4, 208-5, 208-6, and 208-7 in FIGs. 1 and 2.

[0041] The DM-RS transmission 308-1 corresponds to the PUSCH transmission 306-1 , the DM-RS transmission 308-2 corresponds to the PUSCH transmission 306- 2, the DM-RS transmission 308-3 corresponds to the PUSCH transmission 306-3, the DM-RS transmission 308-4 corresponds to the PUSCH transmission 306-4, the DM-RS transmission 308-5 corresponds to the PUSCH transmission 306-5, and the DM-RS transmission 308-6 corresponds to the PUSCH transmission 306-6.

[0042] In a number of examples, each of the DM-RS transmissions 308 can be transmitted on the SC-FDMA symbols with multiple indices. For example, the DM- RS transmission 308-2 is transmitted on the SC-FDMA symbols with indices 8 and 1 1 . The DM-RS transmission 308-3 is transmitted on the SC-FDMA symbols with indices 5 and 8. The DM-RS transmission 308-3 is transmitted on the SC-FDMA symbols with indices 5 and 8. The DM-RS transmission 308-4 is transmitted on the SC-FDMA symbols with indices 5 and 2.

[0043] In FIG. 3, a portion of the DM-RS transmissions (e.g., DM-RS

transmissions 308-1 and 308-6) is transmitted on a single SC-FDMA symbol with a particular index (e.g., the indices 302 with a value equal to 2 and 1 1 ) even though the other DM-RS transmissions (e.g., DM-RS transmissions 308-2, 308-3, 308-4, and 308-5) are transmitted on multiple SC-FDMA symbols with different indices. For example, the DM-RS transmission 308-6 is transmitted on the SC-FDMA symbol with indices equal to 2 which corresponds to the PUSCH transmission 306-6 transmitted on the SC-FDMA symbols with indices equal to 0 and 1. [0044] In some examples, the DM-RS transmissions are transmitted on a single SC-FDMA symbol if the associated PUSCH transmission is transmitted at the beginning and/or end of the uplink subframe 300 and/or at the beginning and/or end of the first slot and/or the second slot of the uplink subframe 300.

[0045] In the other embodiment the DM-RS transmissions may be transmitted on multiple (e.g. two or more SC-FDMA symbols) if the associated PUSCH transmission is transmitted at the beginning and/or end of the uplink subframe 300 and/or at the at the beginning and/or end of the first slot and/or the second slot of the uplink subframe 300. The DM-RS transmission on one of the SC-FDMA symbols in this case can be performed in the previous or following uplink subframe.

[0046] The DM-RS transmissions 308 may be transmitted on SC-FDMA symbols that are near the PUSCH transmissions 306. For example, the DM-RS transmission 308-1 that is transmitted on the SC-FDMA symbol 302 with a value equal to 1 1 is next to the corresponding PUSCH transmission 306-1 which is transmitted on the SC-FDMA symbols with indices with values equal to 12 and 13. The DM-RS transmission 308-1 is considered to be transmitted next to the PUSCH transmission 306-1 because the index (e.g., the index with a value equal to 1 1 ) on which the DM- RS transmission 308-1 is transmitted is numerically consecutive with the index (e.g., the index with a value equal to 12 and 13) on which the PUSCH transmission 306-1 is transmitted. The DM-RS transmission 308 can be transmitted on SC-FDMA symbols that are near the PUSCH transmissions 306 if all of the SC-FDMA symbol indices on which the DM-RS transmissions 308 are transmitted are numerically near the SC-FDMA symbol indices on which the PUSCH transmissions are transmitted. For example, the DM-RS transmission 308-3 is near the PUSCH transmission 306-3 because the DM-RS transmission 308-3 is transmitted on the SC-FDMA symbols with indices equal to 5 and 8 and the PUSCH transmission 306-3 is transmitted on the SC-FDMA symbols with indices equal to 6 and 7.

[0047] Although the examples shown in FIGs. 1 , 2, and 3 show PUSCH

transmissions being transmitted over two SC-FDMA symbols, the PUSCH

transmissions can be transmitted over more than two SC-FDMA symbols. FIGs. 1 , 2, and 3 also show one or two PUSCH transmissions being transmitted over two SC- FDMA symbols. However, more than two PUSCH transmissions can be transmitted over one, two, or more SC-FDMA symbols. [0048] Although in the examples shown in FIG. 1 the DM-RS transmission is performed on different subcarriers of the same SC-FDMA symbol, the DM-RS transmissions may be also performed on the same subcarriers. If the transmission of DM-RS corresponding to different PUSCH transmission is performed on the same subcarriers different cyclic shift (or orthogonal DFT codes) can be used for the corresponding PUSCH transmissions.

[0049] FIG. 4 is a block diagram illustrating electronic device circuitry that may be eNodeB circuitry, user equipment (UE) circuitry, network node circuitry, or some other type of circuitry according to one embodiment. FIG. 4 illustrates an electronic device 400 that may be, or may be incorporated into or otherwise part of, an eNB, a UE, a CloT device, a CloT eNB, a firmware pusher device, or some other type of electronic device in accordance with various embodiments. In some embodiments, the firmware pusher device may be a device that implements all or part of a firmware pusher functionality as hardware, firmware, logic, circuitry, modules, and/or software. Specifically, the electronic device 400 may be logic and/or circuitry that may be at least partially implemented in one or more of hardware, software, and/or firmware. In embodiments, the electronic device logic may include radio transmit/transmitter logic (e.g., a first transmitter logic 477) and receive/receiver logic (e.g., a first receiver logic 483) coupled to a control logic 473 and/or a processor 471 . In embodiments, the transmit/transmitter and/or receive/receiver logic may be elements or modules of transceiver logic. The first transmitter logic 477 and the first receiver logic 483 may be housed in separate devices. For example, the first transmitter logic 477 can be incorporated into a first device while the first receiver logic 483 is incorporated into a second device, or the transmitter logic 477 and the receiver logic 483 can be incorporated into a device separate from a device including any combination of the control logic 473, a memory 479, and/or the processor 471 . The electronic device 400 may be coupled with or include one or more antenna elements 485 of one or more antennas. The electronic device 400 and/or the components of the electronic device 400 may be configured to perform operations similar to those described elsewhere in this disclosure.

[0050] In embodiments where the electronic device 400 implements, is

incorporated into, or is otherwise part of a UE, or device portion thereof, that is implementing a schedule for DL/UL including low latency subframe structures and/or high throughput subframe structures, a first receiver and a first transmitter may receive and send PDCCH, PDSCH, PUSCH, GP, and/or PUCCH transmissions. The processor 471 may be coupled to the first receiver and first transmitter. A memory 479 may be coupled to the processor 471 having control logic instructions thereon that when executed receives the PDCCH, the PDSCH, and/or the PUCCH transmissions and generates and/or transmits the PUSCH and/or the PUCCH.

[0051] In embodiments where the electronic device 400 receives data, generates data, and/or transmits data to/from an eNodeB to implement a schedule for generating and/or transmitting data using low latency subframe structures, the processor 471 may be coupled to a receiver and a transmitter. The memory 479 may be coupled to the processor 471 having control logic 473 instructions thereon that when executed may be to identify one or more parameters related to low latency subframe structures in at least one of a radio frame and a subframe and generate and/or transmit at least one of a downlink control information (DCI) format or a dedicated control channel data in accordance with the one or more parameters. Wherein the one or more parameters include a position of the DM-RS transmission in a time domain and a frequency domain.

[0052] As used herein, the term "logic" may refer to, be part of, or include an Application Specific Integrated Circuit (ASIC), an electronic circuit, the processor 471 (shared, dedicated, or group), and/or the memory 479 (shared, dedicated, or group) that execute one or more software or firmware programs, a combinational logic circuit, and/or other suitable hardware components that provide

the described functionality. Specifically, the logic may be at least partially

implemented in, or an element of, hardware, software, and/or firmware. In some embodiments, the electronic device logic may be implemented in, or functions associated with the logic may be implemented by, one or more software or firmware modules.

[0053] FIG. 5 is a block diagram illustrating a method 520 for a UL schedule according to one embodiment. The method 520 can include a method for an uplink DM-RS transmission by a UE with a shortened TTI. The method 520 includes receiving 522, from a serving cell, PUSCH parameters including a position of the DM-RS transmission in a time domain and a frequency domain. The DM-RS transmission, in the frequency domain, is transmitted in a pattern that is repeated 524 over p subcarriers within a PUSCH resource allocation, wherein p is greater than one (p > 1 ). The method 520 also includes generating 526 a PUSCH

transmission in accordance with the PUSCH parameters.

[0054] The position of the DM-RS transmission can be determined by a frequency shift index, wherein the frequency shift index is an integer with a value between 0 to p-1 inclusive. The frequency shift determines one out of p subcarrier sets that can be used for DM-RS transmission on a given SC-FDMA symbols. In a number of examples, p can correspond to one of 2, 3, and 4.

[0055] The position of the DM-RS transmission in the time domain is determined in accordance with a single-carrier frequency-division multiple access (SC-FDMA) symbol index of the PUSCH resource allocation. That is, the PUSCH resource allocation can define an SC-FDMA symbol index and/or a plurality of SC-FDMA symbol indices on which the DM-RS transmission is transmitted.

[0056] In some examples, the position of the DM-RS transmission is an SC- FDMA symbol with an index equal to 0, if the PUSCH transmission is transmitted on any of the first 7 SC-FDMA symbols. For example, the DM-RS transmission can be transmitted on the SC-FDMA symbol index with a value equal to any of 1 to 6.

[0057] In one example, the position of the DM-RS transmission is an SC-FDMA symbol with an index equal to 3, if the PUSCH transmission is transmitted on any of a first 7 SC-FDMA symbols. For example the DM-RS transmission can be transmitted on the SC-FDMA symbol with an index equal to 3, if the PUSCH transmission is transmitted on any of the SC-FDMA symbols with an index with a value equal to 0 to 2 and 4 to 6.

[0058] In some examples, the position of the DM-RS transmission is an SC- FDMA symbol with an index equal to 7, if the PUSCH transmission is transmitted on any of a second 7 SC-FDMA symbols. For example, the DM-RS transmission can be transmitted on the SC-FDMA symbol with an index equal to 7 (e.g., the first index on the second slot of the subframe), if the PUSCH transmission is transmitted on any of the SC-FDMA symbols with an index with a value equal to 8 to 13.

[0059] In yet another example, the position of the DM-RS transmission is the SC- FDMA symbol with an index equal to 10, if the PUSCH transmission is transmitted on any of a second 7 SC-FDMA symbols. For example, the DM-RS transmission can be transmitted on the SC-FDMA symbol with an index equal to 10, if the PUSCH transmission is transmitted on any of the SC-FDMA symbols with an index equal to 7 to 13. [0060] The PUSCH transmission can occupy any number of a 1 , 2, 3, 4, 5, 6 and 7 SC-FDMA symbols. For example, the PUSCH transmission can occupy any plurality of consecutive SC-FDMA symbols with an index value between 0 and 6. The PUSCH transmission can occupy the SC-FDMA symbols with indices values equal 0 and 1 or 0, 1 and 2. In some embodiments, the PUSCH transmission can occupy nonconsecutive SC-FDMA symbols with an index value between 0 and 6.

[0061] In some embodiments, the PUSCH parameters include a DM-RS cyclic shift. In one embodiment, more than one of the DM-RS symbols can be transmitted by a UE for the PUSCH transmission with a shortened TTI. For example, the DM- RS transmission can be transmitted on a first SC-FDMA symbol and a second SC- FDMA symbol. The more than one of the DM-RS symbols can be transmitted on an SC-FDMA symbol adjacent to SC-FDMA symbols of the PUSCH transmission as described above. In some embodiments, signaling is a physical layer signaling associated with a downlink control indicator.

[0062] FIG. 6 is a block diagram illustrating a method 620 for a UL schedule according to one embodiment. The method 620 includes receiving 632 via an RF circuitry and from an evolved eNodeB, a first PUSCH signal.

[0063] The method 620 can also include determining 634 via a baseband circuitry coupled with the RF circuitry, from the first PUSCH signal, a position of a DM-RS, in a time domain and a frequency domain. The first PUSCH signal can be received at a UE. The UE can determine, based on the first PUSCH signal received, a position of the DM-RS transmission that can be transmitted by, for example, a baseband processor of the UE.

[0064] In the method 620, the RF circuitry can further be configured to generate 636 and/or transmit, to the eNodeB, a second PUSCH signal in accordance with the determined DM-RS, wherein the DM-RS, wherein the DM-RS transmission in the frequency domain is transmitted in a pattern 638 that is repeated over p subcarriers within a PUSCH resource allocation, and wherein p > 1 .

[0065] In the method 620, p can correspond to one of 2, 3, and 4. That is, p can describe a pattern that the DM-RS is transmitted in such that the DM-RS

transmission is transmitted in a pattern that is repeated over p subcarriers.

[0066] The method 620 wherein the position of the DM-RS transmission in the time domain is determined in accordance with an SC-FDMA symbol index of the PUSCH resource allocation. [0067] FIG. 7 is a block diagram illustrating a method 720 for a UL schedule according to one embodiment. The method 720 includes generating 742 a first PUSCH signal, the signal including an indication of a position of a DM-RS in a time domain and a frequency domain. The generated first PUSCH signal can be transmitted, via baseband processors of the eNodeB, to a UE.

[0068] The method 720 can also include receiving 744, from the UE, a second PUSCH signal in accordance with the indication of the position of the DM-RS in the time domain and the frequency domain. The method 720 can also include determining 746 the indication of the position of the DM-RS in the time and the frequency domain, wherein the DM-RS transmission in the frequency domain is transmitted in a pattern 748 that is repeated over p subcarriers within a PUSCH resource allocation, wherein p > 1 .

[0069] FIG. 8 is a block diagram illustrating components of a UE device according to one embodiment. In some embodiments, the UE device may include application circuitry 803, baseband circuitry 805, Radio Frequency (RF) circuitry 807, front-end module (FEM) circuitry 809, and one or more antennas 814, coupled together at least as shown in FIG. 8.

[0070] The application circuitry 803 may include one or more application processors. By way of non-limiting example, the application circuitry 803 may include one or more single-core or multi-core processors. The processor(s) may include any combination of general-purpose processors and dedicated processors (e.g., graphics processors, application processors, etc.). The processor(s) may be operably coupled and/or include memory/storage, and may be configured to execute instructions stored in the memory/storage to enable various applications

and/or operating systems to run on the system.

[0071] By way of non-limiting example, the baseband circuitry 805 may include one or more single-core or multi-core processors. The baseband circuitry 805 may include one or more baseband processors and/or control logic. The baseband circuitry 805 may be configured to process baseband signals received from a receive signal path of the RF circuitry 807. The baseband circuitry 805 may also be configured to generate baseband signals for a transmit signal path of the RF circuitry 807. The baseband circuitry 805 may interface with the application circuitry 803 for generation and processing of the baseband signals, and for controlling operations of the RF circuitry 807. [0072] By way of non-limiting example, the baseband circuitry 805 may include at least one of a second generation (2G) baseband processor 81 1 A, a third generation (3G) baseband processor 81 1 B, a fourth generation (4G) baseband processor 81 1 C, other baseband processor(s) 81 1 D for other existing generations, and generations in development or to be developed in the future (e.g., fifth generation (5G), 6G, etc.). The baseband circuitry 805 (e.g., at least one of the baseband processors 81 1 A- 81 1 D) may handle various radio control functions that enable communication with one or more radio networks via the RF circuitry 807. By way of non-limiting example, the radio control functions may include signal modulation/demodulation,

encoding/decoding, radio frequency shifting, other functions, and combinations thereof. In some embodiments, modulation/demodulation circuitry of the baseband circuitry 805 may be programmed to perform Fast-Fourier Transform (FFT), precoding, constellation mapping/demapping functions, other functions, and combinations thereof. In some embodiments, encoding/decoding circuitry of the baseband circuitry 805 may be programmed to perform convolutions, tail-biting convolutions, turbo, Viterbi, Low Density Parity Check (LDPC) encoder/decoder functions, other functions, and combinations thereof. Embodiments of

modulation/demodulation and encoder/decoder functions are not limited to these examples, and may include other suitable functions.

[0073] In some embodiments, the baseband circuitry 805 may include elements of a protocol stack. By way of non-limiting example, elements of an evolved universal terrestrial radio access network (EUTRAN) protocol including, for example, physical (PHY), media access control (MAC), radio link control (RLC), packet data convergence protocol (PDCP), and/or radio resource control (RRC) elements. A central processing unit (CPU) 81 1 E of the baseband circuitry 805 may be

programmed to run elements of the protocol stack for signaling of the PHY, MAC, RLC, PDCP and/or RRC layers. In some embodiments, the baseband circuitry 805 may include one or more audio digital signal processor(s) (DSP) 81 1 F. The audio DSP(s) 81 1 F may include elements for compression/decompression and echo cancellation. The audio DSP(s) 81 1 F may also include other suitable processing elements.

[0074] The baseband circuitry 805 may further include a memory/storage 81 1 G. The memory/storage 81 1 G may include data and/or instructions for operations performed by the processors of the baseband circuitry 805 stored thereon. In some embodiments, the memory/storage 81 1 G may include any combination of suitable volatile memory and/or non-volatile memory. The memory/storage 81 1 G may also include any combination of various levels of memory/storage including, but not limited to, read-only memory (ROM) having embedded software instructions (e.g., firmware), random access memory (e.g., dynamic random access memory (DRAM)), cache, buffers, etc. In some embodiments, the memory/storage 81 1 G may be shared among the various processors or dedicated to particular processors.

[0075] Components of the baseband circuitry 805 may be suitably combined in a single chip, a single chipset, or disposed on a same circuit board in some

embodiments. In some embodiments, some or all of the constituent components of the baseband circuitry 805 and the application circuitry 803 may be

implemented together, such as, for example, on a system on a chip (SOC).

[0076] In some embodiments, the baseband circuitry 805 may provide for communication compatible with one or more radio technologies. For example, in some embodiments, the baseband circuitry 805 may support communication with an evolved universal terrestrial radio access network (EUTRAN) and/or other wireless metropolitan area networks (WMAN), a wireless local area network (WLAN), or a wireless personal area network (WPAN). Embodiments in which the baseband circuitry 805 is configured to support radio communications of more than one wireless protocol may be referred to as multi-mode baseband circuitry.

[0077] The RF circuitry 807 may enable communication with wireless networks using modulated electromagnetic radiation through a non-solid medium. In various embodiments, the RF circuitry 807 may include switches, filters, amplifiers, etc. to facilitate the communication with the wireless network. The RF circuitry 807 may include a receive signal path which may include circuitry to down-convert RF signals received from the FEM circuitry 809, and provide baseband signals to the baseband circuitry 805. The RF circuitry 807 may also include a transmit signal path which may include circuitry to up-convert baseband signals provided by the baseband circuitry 805, and provide RF output signals to the FEM circuitry 809 for

transmission.

[0078] In some embodiments, the RF circuitry 807 may include a receive signal path and a transmit signal path. The receive signal path of the RF circuitry 807 may include a mixer circuitry 813A, an amplifier circuitry 813B, and a filter circuitry 813C. The transmit signal path of the RF circuitry 807 may include the filter circuitry 813C and the mixer circuitry 813A. The RF circuitry 807 may further include a synthesizer circuitry 813D configured to synthesize a frequency for use by the mixer circuitry 813A of the receive signal path and the transmit signal path. In some embodiments, the mixer circuitry 813A of the receive signal path may be configured to down- convert RF signals received from the FEM circuitry 809 based on the synthesized frequency provided by the synthesizer circuitry 813D. The amplifier circuitry 813B may be configured to amplify the down-converted signals.

[0079] The filter circuitry 813C may include a low-pass filter (LPF) or band-pass filter (BPF) configured to remove unwanted signals from the down-converted signals to generate output baseband signals. Output baseband signals may be provided to the baseband circuitry 805 for further processing. In some embodiments, the output baseband signals may include zero-frequency baseband signals, although this is not a requirement. In some embodiments, the mixer circuitry 813A of the receive signal path may comprise passive mixers, although the scope of the embodiments is not limited in this respect.

[0080] In some embodiments, the mixer circuitry 813A of the transmit signal path may be configured to up-convert input baseband signals based on the synthesized frequency provided by the synthesizer circuitry 813D to generate RF output signals for the FEM circuitry 809. The baseband signals may be provided by the baseband circuitry 805 and may be filtered by the filter circuitry 813C. The filter circuitry 813C may include a low-pass filter (LPF), although the scope of the embodiments is not limited in this respect.

[0081] In some embodiments, the mixer circuitry 813A of the receive signal path and the mixer circuitry 813A of the transmit signal path may include two or more mixers, and may be arranged for quadrature downconversion and/or upconversion, respectively. In some embodiments, the mixer circuitry 813A of the receive signal path and the mixer circuitry 813A of the transmit signal path may include two or more mixers and may be arranged for image rejection (e.g., Hartley image rejection). In some embodiments, the mixer circuitry 813A of the receive signal path and the mixer circuitry 813A of the transmit signal path may be arranged for direct downconversion and/or direct upconversion, respectively. In some embodiments, the mixer circuitry 813A of the receive signal path and the mixer circuitry 813A of the transmit signal path may be configured for super-heterodyne operation. [0082] In some embodiments, the output baseband signals and the input baseband signals may be analog baseband signals, although the scope of the embodiments is not limited in this respect. In some alternate embodiments, the output baseband signals and the input baseband signals may be digital baseband signals. In such embodiments, the RF circuitry 807 may include analog-to-digital converter (ADC) and digital-to-analog converter (DAC) circuitry, and the baseband circuitry 805 may include a digital baseband interface to communicate with the RF circuitry 807.

[0083] In some dual-mode embodiments, separate radio IC circuitry may be provided for processing signals for each spectrum, although the scope of the embodiments is not limited in this respect.

[0084] In some embodiments, the synthesizer circuitry 813D may include one or more of a fractional-N synthesizer and a fractional N/N+1 synthesizer, although the scope of the embodiments is not limited in this respect as other types of frequency synthesizers may be suitable. For example, the synthesizer circuitry 813D may include a delta-sigma synthesizer, a frequency multiplier, a synthesizer comprising a phase-locked loop with a frequency divider, other synthesizers and combinations thereof.

[0085] The synthesizer circuitry 813D may be configured to synthesize an output frequency for use by the mixer circuitry 813A of the RF circuitry 807 based on a frequency input and a divider control input. In some embodiments, the synthesizer circuitry 813D may be a fractional N/N+1 synthesizer.

[0086] In some embodiments, frequency input may be provided by a voltage controlled oscillator (VCO), although that is not a requirement. Divider control input may be provided by either the baseband circuitry 805 or the application circuitry 803 depending on the desired output frequency. In some embodiments, a divider control input (e.g., N) may be determined from a look-up table based on a channel indicated by the application circuitry 803.

[0087] The synthesizer circuitry 813D of the RF circuitry 807 may include a divider, a delay-locked loop (DLL), a multiplexer and a phase accumulator. In some embodiments, the divider may include a dual modulus divider (DMD), and the phase accumulator may include a digital phase accumulator (DPA). In some embodiments, the DMD may be configured to divide the input signal by either N or N+1 (e.g., based on a carry out) to provide a fractional division ratio. In some example embodiments, the DLL may include a set of cascaded, tunable, delay elements, a phase detector, a charge pump and a D-type flip-flop. In such embodiments, the delay elements may be configured to break a VCO period up into Nd equal packets of phase, where Nd is the number of delay elements in the delay line. In this way, the DLL may provide negative feedback to help ensure that the total delay through the delay line is one VCO cycle.

[0088] In some embodiments, the synthesizer circuitry 813D may be configured to generate a carrier frequency as the output frequency. In some embodiments, the output frequency may be a multiple of the carrier frequency (e.g., twice the carrier frequency, four times the carrier frequency, etc.) and used in conjunction with a quadrature generator and divider circuitry to generate multiple signals at the carrier frequency with multiple different phases with respect to each other. In some embodiments, the output frequency may be an LO frequency (fLO). In some embodiments, the RF circuitry 807 may include an IQ/polar converter.

[0089] The FEM circuitry 809 may include a receive signal path which may include circuitry configured to operate on RF signals received from the one or more antennas 814, amplify the received signals, and provide the amplified versions of the received signals to the RF circuitry 807 for further processing. The FEM circuitry 809 may also include a transmit signal path which may include circuitry configured to amplify signals for transmission provided by the RF circuitry 807 for transmission by at least one of the one or more antennas 814.

[0090] In some embodiments, the FEM circuitry 809 may include a TX/RX switch configured to switch between a transmit mode and a receive mode operation. The FEM circuitry 809 may include a receive signal path and a transmit signal path. The receive signal path of the FEM circuitry 809 may include a low-noise amplifier (LNA) to amplify received RF signals and provide the amplified received RF signals as an output (e.g., to the RF circuitry 807). The transmit signal path of the FEM circuitry 809 may include a power amplifier (PA) configured to amplify input RF signals (e.g., provided by the RF circuitry 807), and one or more filters configured to generate RF signals for subsequent transmission (e.g., by one or more of the one or more antennas 814).

[0091] In some embodiments, the UE device may include additional elements such as, for example, memory/storage, a display, a camera, one of more sensors, an input/output (I/O) interface, other elements, and combinations thereof. [0092] In some embodiments, the UE device may be configured to perform one or more processes, techniques, and/or methods as described herein, or portions thereof.

[0093] FIG. 9 is a block diagram illustrating components, according to some example embodiments, able to read instructions from a machine-readable or computer-readable medium (e.g., a machine-readable storage medium) and perform any one or more of the methodologies discussed herein. Specifically, FIG. 9 shows a diagrammatic representation of hardware resources 900 including one or more processors (or processor cores) 910, one or more memory/storage devices 920, and one or more communication resources 930, each of which are communicatively coupled via a bus 940.

[0094] The processors 910 (e.g., a central processing unit (CPU), a reduced instruction set computing (RISC) processor, a complex instruction set computing (CISC) processor, a graphics processing unit (GPU), a digital signal processor (DSP) such as a baseband processor, an application specific integrated circuit (ASIC), a radio-frequency integrated circuit (RFIC), another processor, or any suitable combination thereof) may include, for example, a processor 912 and a processor 914. The memory/storage devices 920 may include main memory, disk storage, or any suitable combination thereof.

[0095] The communication resources 930 may include interconnection and/or network interface components or other suitable devices to communicate with one or more peripheral devices 904 and/or one or more databases 910 via a network 908. For example, the communication resources 930 may include wired communication components (e.g., for coupling via a Universal Serial Bus (USB)), cellular

communication components, Near Field Communication (NFC) components,

Bluetooth® components (e.g., Bluetooth® Low Energy), Wi-Fi® components, and other communication components.

[0096] Instructions 950 may comprise software, a program, an application, an applet, an app, or other executable code for causing at least one of the processors 910 to perform any one or more of the methodologies discussed herein. The instructions 950 may reside, completely or partially, within at least one of the processors 910 (e.g., within the processor's cache memory), the memory/storage devices 920, or any suitable combination thereof. Furthermore, any portion of the instructions 950 may be transferred to the hardware resources 900 from any combination of the peripheral devices 904 and/or the databases 906. Accordingly, the memory of the processors 910, the memory/storage devices 920, the peripheral devices 904, and the databases 906 are examples of computer-readable and machine-readable media.

Example Embodiments

[0097] Example 1 is a computer-readable storage medium. The computer- readable storage medium contains instructions which, when implemented by a computing device, cause the computing device to perform operations for an uplink demodulation reference signal (DM-RS) transmission by a user equipment (UE) with a shortened transmission time interval (TTI). The operations include receiving, from a serving cell, physical uplink shared channel (PUSCH) parameters including a position of the DM-RS transmission in a time domain and a frequency domain, where the DM- RS transmission, in the frequency domain, is transmitted in a pattern that is repeated over p subcarriers within a PUSCH resource allocation, and generating a PUSCH transmission in accordance with the PUSCH parameters.

[0098] In Example 2, the subject matter of Example 1 or any of the Examples described herein may further include the computer-readable storage medium where the position of the DM-RS transmission is determined by a frequency shift index, and where the frequency shift index is an integer with a value between 0 and p-1 inclusive.

[0099] In Example 3, the subject matter of Example 2 or any of the Examples described herein may further include the computer-readable storage medium where p corresponds to one of 2, 3, and 4.

[0100] In Example 4, the subject matter of Example 1 or any of the Examples described herein may further include the computer-readable storage medium where the position of the DM-RS transmission in the time domain is determined in accordance with a single carrier frequency-division multiple access (SC-FDMA) symbol index of the PUSCH resource allocation.

[0101] In Example 5, the subject matter of Example 4 or any of the Examples described herein may further include the computer-readable storage medium where the position of the DM-RS transmission is an SC-FDMA symbol with an index equal to 0, if the PUSCH transmission is transmitted on any of a first 7 SC-FDMA symbols.

[0102] In Example 6, the subject matter of Example 4 or any of the Examples described herein may further include the computer-readable storage medium where the position of the DM-RS transmission is an SC-FDMA symbol with an index equal to 3, if the PUSCH transmission is transmitted on any of a first 7 SC-FDMA symbols.

[0103] In Example 7, the subject matter of Example 4 or any of the Examples described herein may further include the computer-readable storage medium where the position of the DM-RS transmission is an SC-FDMA symbol with an index equal to 7, if the PUSCH transmission is transmitted on any of a second 7 SC-FDMA symbols.

[0104] In Example 8, the subject matter of Example 4 or any of the Examples described herein may further include the computer-readable storage medium where the position of the DM-RS transmission is an SC-FDMA symbol with an index equal to 10, if the PUSCH transmission is transmitted on any of a second 7 SC-FDMA symbols.

[0105] In Example 9, the subject matter of Example 1 or any of the Examples described herein may further include the computer-readable storage medium where the PUSCH transmission occupies any number of a 1 , 2, 3, 4, 5, 6 and 7 SC-FDMA symbols.

[0106] In Example 10, the subject matter of Example 1 or any of the Examples described herein may further include the computer-readable storage medium where the PUSCH parameters include a DM-RS cyclic shift.

[0107] In Example 1 1 , the subject matter of Example 1 or any of the Examples described herein may further include the computer-readable storage medium where more than one of the DM-RS symbols are transmitted by the UE for the PUSCH transmission with a shortened TTI.

[0108] In Example 12, the subject matter of Example 1 1 or any of the Examples described herein may further include the computer-readable storage medium where more than one of the DM-RS symbols are transmitted on an SC-FDMA symbol adjacent to SC-FDMA symbols of the PUSCH transmission.

[0109] In Example 13, the subject matter of Example 1 1 or any of the Examples described herein may further include the computer-readable storage medium where signaling is a physical layer signaling associated with as downlink control indicator.

[0110] Example 14 is a user equipment (UE). The user equipment (UE) contains radio frequency (RF) circuitry to receive, from an evolved NodeB (eNodeB), a first physical uplink shared channel (PUSCH) signal, and baseband circuitry coupled with the RF circuitry. The baseband circuitry determines, from the first PUSCH signal, a position of a demodulation reference signal (DM-RS), in a time domain and a frequency domain, where the RF circuitry further transmits to the eNodeB a second PUSCH signal in accordance with the determined DM-RS, and where the DM-RS transmission in the frequency domain is transmitted in a pattern that is repeated over p subcarriers within a PUSCH resource allocation, and wherein p > 1.

[0111] In Example 15, the subject matter of Example 14 or any of the Examples described herein may further include the apparatus where p corresponds to one of 2, 3, and 4.

[0112] In Example 16, the subject matter of Example 15 or any of the Examples described herein may further include the apparatus where the position of the DM-RS transmission in the time domain is determined in accordance with a single carrier frequency-division multiple access (SC-FDMA) symbol index of the PUSCH resource allocation.

[0113] Example 17 is an apparatus for an evolved NodeB (eNodeB). The evolved NodeB (eNodeB) contains electronic memory and one or more baseband processors. The baseband processors are designed to generate for a user equipment (UE) a first physical uplink shared channel (PUSCH) signal, which signal includes an indication of a position of a demodulation reference signal (DM-RS) in a time domain and a frequency domain. The baseband processors are also designed to receive, from the UE, a second PUSCH signal in accordance with the indication of the position of the DM-RS in the time domain and the frequency domain, and determine the indication of the position of the DM-RS in the time and the frequency domain where the DM-RS transmission in the frequency domain is transmitted in a pattern that is repeated over p subcarriers within a PUSCH resource allocation, wherein p > 1 .

[0114] In Example 18, the subject matter of Example 17 or any of the Examples described herein may further include the apparatus where the position of the DM-RS transmission is determined by a frequency shift index, and where the frequency shift index is an integer with a value between 0 and p-1 inclusive.

[0115] Example 19 is a computer-readable storage medium having instructions stored thereon. The instructions, when implemented by a computing device, cause the computing device to perform operations. The operations include determining, based on a first received physical uplink shared channel (PUSCH) signal, an indication of a position of a demodulation reference signal (DM-RS) in a time domain and a frequency domain. The operations also include generating a second PUSCH signal in accordance with the indication of the position of the DM-RS in the time and frequency domain, where the DM-RS in the frequency domain is transmitted in a pattern that is repeated over p subcarriers within a PUSCH resource allocation, wherein p > 1 .

[0116] In Example 20, the subject matter of Example 19 or any of the Examples described herein may further include the computer-readable storage medium where the position of the DM-RS transmission is determined by a frequency shift index, and where the frequency shift index is an integer with a value between 0 and p-1 inclusive.

[0117] In Example 21 , the subject matter of Example 19 or any of the Examples described herein may further include the computer-readable storage medium where the position of the DM-RS transmission in the time domain is determined in accordance with a SC-FDMA symbol index of the PUSCH resource allocation.

[0118] Example 22 is a method. The method includes receiving, from a serving cell, physical uplink shared channel (PUSCH) parameters including a position of a demodulation reference signal (DM-RS) transmission in a time domain and a frequency domain, where the DM-RS transmission, in the frequency domain, is transmitted in a pattern that is repeated over p subcarriers within a PUSCH resource allocation, and further generating a PUSCH transmission in accordance with the PUSCH parameters.

[0119] In Example 23, the subject matter of Example 22 or any of the Examples described herein may further include the method where the position of the DM-RS transmission is determined by a frequency shift index, and where the frequency shift index is an integer with a value between 0 and p-1 inclusive.

[0120] In Example 24, the subject matter of Example 23 or any of the Examples described herein may further include the method where p corresponds to one of 2, 3, and 4.

[0121] In Example 25, the subject matter of Example 22 or any of the Examples described herein may further include the method where the position of the DM-RS transmission in the time domain is determined in accordance with a single carrier frequency-division multiple access (SC-FDMA) symbol index of the PUSCH resource allocation. [0122] In Example 26, the subject matter of Example 25 or any of the Examples described herein may further include the method where the position of the DM-RS transmission is an SC-FDMA symbol with an index equal to 0, if the PUSCH transmission is transmitted on any of a first 7 SC-FDMA symbols.

[0123] In Example 27, the subject matter of Example 25 or any of the Examples described herein may further include the method where the position of the DM-RS transmission is an SC-FDMA symbol with an index equal to 3, if the PUSCH transmission is transmitted on any of a first 7 SC-FDMA symbols.

[0124] In Example 28, the subject matter of Example 25 or any of the Examples described herein may further include the method where the position of the DM-RS transmission is an SC-FDMA symbol with an index equal to 7, if the PUSCH transmission is transmitted on any of a second 7 SC-FDMA symbols.

[0125] In Example 29, the subject matter of Example 25 or any of the Examples described herein may further include the method where the position of the DM-RS transmission is an SC-FDMA symbol with an index equal to 10, if the PUSCH transmission is transmitted on any of a second 7 SC-FDMA symbols.

[0126] In Example 30, the subject matter of Example 22 or any of the Examples described herein may further include the method where the PUSCH transmission occupies any number of a 1 , 2, 3, 4, 5, 6 and 7 SC-FDMA symbols.

[0127] In Example 31 , the subject matter of Example 22 or any of the Examples described herein may further include the method where the PUSCH parameters include a DM-RS cyclic shift.

[0128] In Example 32, the subject matter of Example 22 or any of the Examples described herein may further include the method where more than one of the DM-RS symbols are transmitted by the UE for the PUSCH transmission with a shortened TTI.

[0129] In Example 33, the subject matter of Example 32 or any of the Examples described herein may further include the method where more than one of the DM-RS symbols are transmitted on an SC-FDMA symbol next to SC-FDMA symbols of the PUSCH transmission.

[0130] In Example 34, the subject matter of Example 22 or any of the Examples described herein may further include the method where signaling is a physical layer signaling associated with as downlink control indicator. [0131] Example 35 is a method. The method includes receiving, from an evolved NodeB (eNodeB) and at a radio frequency (RF) circuitry, a first physical uplink shared channel (PUSCH) signal. The method also includes determining, from the first PUSCH signal, a position of a demodulation reference signal (DM-RS), in a time domain and a frequency domain, wherein the RF circuitry is further to transmit, to the eNodeB, a second PUSCH signal in accordance with the determined DM-RS, and where the DM-RS transmission in the frequency domain is transmitted in a pattern that is repeated over p subcarriers within a PUSCH resource allocation, and wherein p > 1 .

[0132] In Example 36, the subject matter of Example 35 or any of the Examples described herein may further include the method where p corresponds to one of 2, 3, and 4.

[0133] In Example 37, the subject matter of Example 35 or any of the Examples described herein may further include the method where the position of the DM-RS transmission in the time domain is determined in accordance with a single carrier frequency-division multiple access (SC-FDMA) symbol index of the PUSCH resource allocation.

[0134] Example 38 is a method. The method includes generating for a user equipment (UE) a first physical uplink shared channel (PUSCH) signal, which signal includes an indication of a position of a demodulation reference signal (DM-RS) in a time domain and a frequency domain. The method also includes receiving, from the UE, a second PUSCH signal in accordance with the indication of the position of the DM-RS in the time domain and the frequency domain. The method further includes determining the indication of the position of the DM-RS in the time and the frequency domain, where the DM-RS transmission in the frequency domain is transmitted in a pattern that is repeated over p subcarriers within a PUSCH resource allocation, wherein p > 1 .

[0135] In Example 39, the subject matter of Example 38 or any of the Examples described herein may further include the method where the position of the DM-RS transmission is determined by a frequency shift index and where the frequency shift index is an integer with a value between 0 and p-1 inclusive.

[0136] Example 40 is a method. The method includes determining, based on a first received physical uplink shared channel (PUSCH) signal, an indication of a position of a demodulation reference signal (DM-RS) in a time domain and a frequency domain. The method also includes generating a second PUSCH signal in accordance with the indication of the position of the DM-RS in the time and frequency domain, where the DM-RS in the frequency domain is transmitted in a pattern that is repeated over p subcarriers within a PUSCH resource allocation, wherein p > 1 .

[0137] In Example 41 , the subject matter of Example 40 or any of the Examples described herein may further include the method where the position of the DM-RS transmission is determined by a frequency shift index, and where the frequency shift index is an integer with a value between 0 and p-1 inclusive.

[0138] In Example 42, the subject matter of Example 40 or any of the Examples described herein may further include the method where the position of the DM-RS transmission in the time domain is determined in accordance with a SC-FDMA symbol index of the PUSCH resource allocation.

[0139] Example 43 is at least one computer-readable storage medium which contains instructions which, when executed, implement a method as described in any of Examples 22-42.

[0140] Example 44 is an apparatus including a manner to perform a method as identified in any of Examples 22-42.

[0141] Various techniques, or certain aspects or portions thereof, may take the form of program code (i.e., instructions) embodied in tangible media, such as floppy diskettes, CD-ROMs, hard drives, a non-transitory computer readable storage medium, or any other machine-readable storage medium wherein, when the program code is loaded into and executed by a machine, such as a computer, the machine becomes an apparatus for practicing the various techniques. In the case of program code execution on programmable computers, the computing device may include a processor, a storage medium readable by the processor (including volatile and nonvolatile memory and/or storage elements), at least one input device, and at least one output device. The volatile and non-volatile memory and/or storage elements may be a RAM, an EPROM, a flash drive, an optical drive, a magnetic hard drive, or another medium for storing electronic data. The eNB (or other base station) and UE (or other mobile station) may also include a transceiver component, a counter component, a processing component, and/or a clock component or timer component. One or more programs that may implement or utilize the various techniques described herein may use an application programming interface (API), reusable controls, and the like. Such programs may be implemented in a high-level procedural or an object-oriented programming language to communicate with a computer system. However, the program(s) may be implemented in assembly or machine language, if desired. In any case, the language may be a compiled or an interpreted language, and combined with hardware implementations.

[0142] It should be understood that many of the functional units described in this specification may be implemented as one or more components, which is a term used to more particularly emphasize their implementation independence. For example, a component may be implemented as a hardware circuit comprising custom very large scale integration (VLSI) circuits or gate arrays, off-the-shelf semiconductors such as logic chips, transistors, or other discrete components. A component may also be implemented in programmable hardware devices such as field programmable gate arrays, programmable array logic, programmable logic devices, or the like.

[0143] Components may also be implemented in software for execution by various types of processors. An identified component of executable code may, for instance, comprise one or more physical or logical blocks of computer instructions, which may, for instance, be organized as an object, a procedure, or a function.

Nevertheless, the executables of an identified component need not be physically located together, but may comprise disparate instructions stored in different locations that, when joined logically together, comprise the component and achieve the stated purpose for the component.

[0144] Indeed, a component of executable code may be a single instruction, or many instructions, and may even be distributed over several different code

segments, among different programs, and across several memory devices. Similarly, operational data may be identified and illustrated herein within components, and may be embodied in any suitable form and organized within any suitable type of data structure. The operational data may be collected as a single data set, or may be distributed over different locations including over different storage devices, and may exist, at least partially, merely as electronic signals on a system or network. The components may be passive or active, including agents operable to perform desired functions.

[0145] Reference throughout this specification to "an example" means that a particular feature, structure, or characteristic described in connection with the example is included in at least one embodiment. Thus, appearances of the phrase "in an example" in various places throughout this specification are not necessarily all referring to the same embodiment.

[0146] As used herein, a plurality of items, structural elements, compositional elements, and/or materials may be presented in a common list for convenience. However, these lists should be construed as though each member of the list is individually identified as a separate and unique member. Thus, no individual member of such list should be construed as a de facto equivalent of any other member of the same list solely based on its presentation in a common group without indications to the contrary. In addition, various embodiments and examples may be referred to herein along with alternatives for the various components thereof. It is understood that such embodiments, examples, and alternatives are not to be construed as de facto equivalents of one another, but are to be considered as separate and autonomous representations of embodiments.

[0147] Although the foregoing has been described in some detail for purposes of clarity, it will be apparent that certain changes and modifications may be made without departing from the principles thereof. It should be noted that there are many alternative ways of implementing both the processes and apparatuses described herein. Accordingly, the present embodiments are to be considered illustrative and not restrictive, and the embodiments is not to be limited to the details given herein, but may be modified within the scope and equivalents of the appended claims.

Claims

1 . A computer-readable storage medium having stored thereon instructions that, when implemented by a computing device, cause the computing device to perform operations for an uplink demodulation reference signal (DM-RS) transmission by a user equipment (UE) with a shortened transmission time interval (TTI), the

operations comprising:

receiving, from a serving cell, physical uplink shared channel (PUSCH) parameters including a position of the DM-RS transmission in a time domain and a frequency domain;

wherein the DM-RS transmission, in the frequency domain, is transmitted in a pattern that is repeated over p subcarriers within a PUSCH resource allocation; and

generating a PUSCH transmission in accordance with the PUSCH

parameters.

2. The computer-readable storage medium of claim 1 , wherein the position of the DM-RS transmission is determined by a frequency shift index, wherein the frequency shift index is an integer with a value between 0 and p-1 inclusive.

3. The computer-readable storage medium of claim 2, wherein p corresponds to one of 2, 3, and 4.

4. The computer-readable storage medium as in claims 1 , 2, or 3, wherein the position of the DM-RS transmission in the time domain is determined in accordance with a single carrier frequency-division multiple access (SC-FDMA) symbol index of the PUSCH resource allocation.

5. The computer-readable storage medium of claim 4, wherein the position of the DM-RS transmission is an SC-FDMA symbol with an index equal to 0, if the PUSCH transmission is transmitted on any of a first 7 SC-FDMA symbols.

6. The computer-readable storage medium of claim 4, wherein the position of the DM-RS transmission is an SC-FDMA symbol with an index equal to 3, if the PUSCH transmission is transmitted on any of a first 7 SC-FDMA symbols.

7. The computer-readable storage medium of claim 4, wherein the position of the DM-RS transmission is an SC-FDMA symbol with an index equal to 7, if the PUSCH transmission is transmitted on any of a second 7 SC-FDMA symbols.

8. The computer-readable storage medium of claim 4, wherein the position of the DM-RS transmission is an SC-FDMA symbol with an index equal to 10, if the PUSCH transmission is transmitted on any of a second 7 SC-FDMA symbols.

9. The computer-readable storage medium as in claims 1 , 2, or 3, wherein the PUSCH transmission that occupies any number of a 1 , 2, 3, 4, 5, 6 and 7 SC-FDMA symbols.

10. The computer-readable storage medium as in claims 1 , 2, or 3, wherein the PUSCH parameters include a DM-RS cyclic shift.

1 1 . The computer-readable storage medium as in claims 1 , 2, or 3, wherein more than one of the DM-RS symbols are transmitted by the UE for the PUSCH

transmission with a shortened TTI.

12. The computer-readable storage medium of claim 1 1 , wherein the more than one of the DM-RS symbols are transmitted on an SC-FDMA symbol adjacent to SC- FDMA symbols of the PUSCH transmission.

13. The computer-readable storage medium of claim 1 1 , wherein signaling is a physical layer signaling associated with as downlink control indicator.

14. A user equipment (UE), comprising:

radio frequency (RF) circuitry to receive, from an evolved NodeB (eNodeB), a first physical uplink shared channel (PUSCH) signal; and

baseband circuitry coupled with the RF circuitry, the baseband circuitry to determine, from the first PUSCH signal, a position of a demodulation reference signal (DM-RS), in a time domain and a frequency domain;

wherein the RF circuitry is further to transmit, to the eNodeB, a second PUSCH signal in accordance with the determined DM-RS; and

wherein the DM-RS transmission in the frequency domain is transmitted in a pattern that is repeated over p subcarriers within a PUSCH resource allocation, and wherein p > 1 .

15. The apparatus of claim 14, wherein p corresponds to one of 2, 3, and 4.

16. The apparatus of claim 15, wherein the position of the DM-RS transmission in the time domain is determined in accordance with a single carrier frequency-division multiple access (SC-FDMA) symbol index of the PUSCH resource allocation.

17. An apparatus for an evolved NodeB (eNodeB), comprising electronic memory and one or more baseband processors configured to: generate for a user equipment (UE) a first physical uplink shared channel (PUSCH) signal, the signal including an indication of a position of a demodulation reference signal (DM-RS) in a time domain and a frequency domain; and

receive, from the UE, a second PUSCH signal in accordance with the indication of the position of the DM-RS in the time domain and the frequency domain; and

determine the indication of the position of the DM-RS in the time and the frequency domain;

wherein the DM-RS transmission in the frequency domain is transmitted in a pattern that is repeated over p subcarriers within a PUSCH resource allocation, wherein p > 1 .

18. The apparatus of claim 17, wherein the position of the DM-RS transmission is determined by a frequency shift index, wherein the frequency shift index is an integer with a value between 0 and p-1 inclusive.

19. A computer-readable storage medium having stored thereon instructions that, when implemented by a computing device, cause the computing device to perform operations, the operations comprising:

determining, based on a first received physical uplink shared channel

(PUSCH) signal, an indication of a position of a demodulation reference signal (DM- RS) in a time domain and a frequency domain; and

generating, a second PUSCH signal in accordance with the indication of the position of the DM-RS in the time and frequency domain;

wherein the DM-RS in the frequency domain is transmitted in a pattern that is repeated over p subcarriers within a PUSCH resource allocation, wherein p > 1 .

20. The computer-readable storage medium of claim 19, wherein the position of the DM-RS transmission is determined by a frequency shift index, wherein the frequency shift index is an integer with a value between 0 and p-1 inclusive.

21 . The computer-readable storage medium of claim 19 wherein the position of the DM-RS transmission in the time domain is determined in accordance with a SC- FDMA symbol index of the PUSCH resource allocation.