WTRU and method used in WTRU

Abstract

The invention discloses a WTRU and a method used in the WTRU. A wireless transmit / receive unit (WTRU) using hybrid parameter configuration may map a first set of bits to a higher order modulation scheme and a second set of bits to a lower order scheme within a first codeword and transmit the first codeword. The WTRU may determine that data of the first codeword is to be retransmitted on a second codeword, the second codeword including a same number of bits as the first codeword. Within a second codeword, the WTRU may map a first set of bits to the lower order scheme and a second set of bits to the higher order scheme. The first set of bits of the second codeword may include a same number of bits as the second set of bits of the first codeword, and may include at least a subset of data within the first set of bits of the first codeword. The WTRU may transmit the second codeword.

Description

[0001] This case is a divisional application of Chinese invention patent application 202110943900.X, entitled “Physical (PHY) layer scheme supporting mixed parameter configuration in the same channel”, filed on August 17, 2021.

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This application claims the benefit of U.S. Provisional Patent Application No. 62 / 334,882, filed May 11, 2016, the contents of which are incorporated herein by reference. Background Art

[0004] New applications are constantly emerging for wireless cellular technologies. For these new applications, the importance of support for higher data rates, lower latency, and large-scale connections continues to increase. For example, the International Telecommunication Union (ITU) has recommended support for enhanced mobile broadband (eMBB) communications, ultra-reliable low-latency communications (URLLC), and massive machine-type communications (mMTC) along with some exemplary use cases and desired radio access capabilities. The importance of radio access capabilities may vary for a wide range of applications and use cases.

[0005] For example, for eMBB, spectral efficiency, capacity, user data rate (e.g., peak data rate, average data rate, or both), and mobility may be very important. For eMBB use cases, the choice of waveform and parameter configuration can potentially improve spectral efficiency. For URLLC, user plane latency may be very important. The choice of parameter configuration can help address this aspect. For example, for waveforms based on orthogonal frequency division multiplexing (OFDM) / discrete Fourier transform-spread-orthogonal frequency division multiplexing (DFT-s-OFDM), if wide subcarrier spacing is configured, the OFDM symbol length can be shorter, which can help reduce physical (PHY) layer latency.

[0006] For mMTC, connection density, low device complexity, low power consumption, and extended coverage may be very important. The choice of waveform type and parameter configuration may address some of these requirements. For example, for OFDM waveform-based systems, a longer cyclic prefix (CP) may be configured for longer OFDM symbols. This may ease timing requirements and may allow the use of lower cost local oscillators. For example, longer OFDM symbols may be configured with narrower subcarrier spacing. Summary of the invention

[0007] Methods, devices, and systems for improving system performance and spectral efficiency when using hybrid orthogonal frequency division modulation (OFDM) waveform parameter configurations within adjacent partitions of a single channel are discussed herein. The exemplary methods, devices, and systems include mapping a lower order modulation to a first resource near a partition edge, and mapping a higher order modulation to a second resource closer to a partition center and away from the partition edge.

[0008] More specifically, in one example, a wireless transmit / receive unit (WTRU) may map a first set of bits in a first codeword to a higher order modulation scheme and a second set of bits in the first codeword to a lower order modulation scheme. The WTRU may then transmit the first codeword. Thereafter, an eNodeB may receive the first codeword. Further, the WTRU may determine that data of the first codeword will be retransmitted on a second codeword, the second codeword comprising the same number of bits as the first codeword. Thereafter, the WTRU may map the first set of bits in the second codeword to the lower order modulation scheme and map the second set of bits in the second codeword to the higher order modulation scheme. The first set of bits of the second codeword may comprise the same number of bits as the second set of bits of the first codeword and may comprise at least a subset of the data in the first set of bits of the first codeword. Thereafter, the WTRU may transmit the second codeword. Thereafter, the eNodeB may receive the second codeword.

[0009] In a further example, the WTRU may receive an assignment message from an eNodeB, the assignment message including instructions regarding partition determination and resource assignment. Accordingly, the WTRU may determine at least two partitions of a bandwidth for wireless communication based on the assignment message, wherein each of the at least two partitions has a different symbol period, a different subcarrier spacing, or both. Further, the WTRU may assign resource blocks (RBs) of the at least two partitions based on the assignment message, wherein RBs within a partition that are close to an adjacent partition in at least one of a time resource and a frequency resource are assigned the lower modulation scheme, and wherein the first codeword is transmitted using the assigned RBs. In an example, a first partition may have a first parameter configuration, and a second partition may have a second parameter configuration.

[0010] Further, a base station (such as an eNodeB) may determine that the data of the first codeword is to be retransmitted based on a low signal-to-noise-and-interference ratio (SINR) of the transmitted first codeword. The eNodeB may transmit a message to the WTRU, the message including an instruction to retransmit the data of the first codeword. Based on the received message, the WTRU may determine that the data of the first codeword is to be retransmitted. In addition, the mapping of the bits of the codeword may be based on at least one of: a predefined process, a dynamically signaled process, and a process signaled within downlink control information (DCI).

[0011] In another example, the eNodeB may map a first set of bits within a first codeword to a higher order modulation scheme and map a second set of bits within the first codeword to a lower order modulation scheme. Thereafter, the eNodeB may transmit the first codeword. Thereafter, the WTRU may receive the first codeword. Further, the eNodeB may determine that data of the first codeword will be retransmitted on a second codeword, and the second codeword may include the same number of bits as the first codeword. Thereafter, the eNodeB may map the first set of bits within the second codeword to the lower order modulation scheme and map the second set of bits within the second codeword to the higher order modulation scheme. The first set of bits of the second codeword may include the same number of bits as the second set of bits of the first codeword and may include at least a subset of the data within the first set of bits of the first codeword. Thereafter, the eNodeB transmits the second codeword, and thereafter, the WTRU may receive the second codeword.

[0012] In an additional example, the eNodeB may determine at least two partitions of a bandwidth for wireless communication, wherein each of the at least two partitions has a different symbol period, a different subcarrier spacing, or both. Further, the eNodeB may assign RBs of the at least two partitions, wherein RBs within a partition that are close to an adjacent partition in at least one of a time resource and a frequency resource are assigned the lower modulation scheme, and wherein the first codeword is transmitted using the assigned RBs. In an example, the first partition may have a first parameter configuration and the second partition may have a second parameter configuration. In an example, the eNodeB may generate and transmit an assignment message to the WTRU, the assignment message including the partition determination and the resource assignment.

[0013] In a further example, the eNodeB may determine that data of the first codeword will be retransmitted based on a low SINR rate of the transmitted first codeword. For example, in addition to or in lieu of the SINR rate, the eNodeB may make the determination based on other considerations. Thereafter, the eNodeB may retransmit the data on the second codeword. Additionally, the mapping of the bits of the codeword may be based on at least one of: a predefined process, a process dynamically signaled, and a process signaled within a DCI. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] A more detailed understanding may be obtained from the following description given by way of example in conjunction with the accompanying drawings, in which:

[0015] Figure 1A is a system diagram of an exemplary communication system in which one or more disclosed embodiments may be implemented;

[0016] Figure 1B Yes, you can Figure 1A A system diagram of an exemplary wireless transmit / receive unit (WTRU) for use within a communication system is shown;

[0017] Figure 1C Yes, you can Figure 1A A system diagram of an exemplary radio access network and an exemplary core network used within the illustrated communication system;

[0018] Figure 2 A schematic diagram illustrating an example of in-band use of hybrid parameter configuration within a waveform operating within adjacent sectors in a channel bandwidth;

[0019] Figure 3 A schematic diagram illustrating an example of the use of a variable modulation order within a transport block (TB);

[0020] Figure 4 A block diagram illustrating variable modulation order mapping for single-layer single-antenna transmission;

[0021] Figure 5 is a schematic diagram showing changing modulation mapping for retransmission;

[0022] Figure 6 is a flow chart of an example of changing a modulation mapping for a retransmission;

[0023] Figure 7 is a diagram showing an example of signaling an offset for modulation order selection for partition edge resources;

[0024] Figure 8 is a schematic diagram showing an example of frequency division multiplexing (FDM) transmission of two codewords on a single layer;

[0025] Fig. 9 is a schematic diagram showing an example of an interference model for a band edge;

[0026] Fig. 10A and 10B is a signaling diagram showing an example of arranging synchronization signals within a hybrid parameter configuration time-frequency grid;

[0027] Fig.11 is a schematic diagram showing an example of control channel allocation;

[0028] Fig.12 A schematic diagram illustrating an exemplary method for uneven time-domain signal-to-noise-interference (SINR) distribution;

[0029] Fig.13 is a schematic diagram showing an exemplary method for non-uniform time domain SINR distribution per resource block (RB); and

[0030] Fig.14 FIG. 4 is a schematic diagram showing an exemplary method for uneven time-frequency domain SINR distribution in a case of multiple RBs. DETAILED DESCRIPTION

[0031] Figure 1A 1 is a diagram of an exemplary communication system 100 in which one or more disclosed embodiments may be implemented. The communication system 100 may be a multiple access system that provides content such as voice, data, video, messaging, broadcast, etc. to multiple wireless users. The communication system 100 may allow multiple wireless users to access such content by sharing system resources including wireless bandwidth. As an example, the communication system 100 may use one or more channel access methods such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), single carrier FDMA (SC-FDMA), etc.

[0032] like Figure 1AAs shown, the communication system 100 may include wireless transmit / receive units (WTRUs) 102a, 102b, 102c, 102d, a radio access network (RAN) 104, a core network 106, a public switched telephone network (PSTN) 108, the Internet 110, and other networks 112, although it should be appreciated that the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and / or network components. Each WTRU 102a, 102b, 102c, 102d may be any type of device configured to operate and / or communicate in a wireless environment. For example, the WTRUs 102a, 102b, 102c, 102d may be configured to transmit and / or receive wireless signals and may include user equipment (UE), a mobile station, a fixed or mobile subscriber unit, a pager, a cellular phone, a personal digital assistant (PDA), a smart phone, a laptop, a netbook, a personal computer, a wireless sensor, a consumer electronic device, and the like.

[0033] The communication system 100 may also include a base station 114a and a base station 114b. Each base station 114a, 114b may be any type of device configured to facilitate access to one or more communication networks, such as the core network 106, the Internet 110, and / or other networks 112, by wirelessly interfacing with at least one WTRU 102a, 102b, 102c, 102d. The base stations 114a, 114b may be, by way of example, a base transceiver station (BTS), a Node B, an eNode B, a Home Node B, a Home eNode B, a site controller, an access point (AP), a wireless router, and the like. Although each base station 114a, 114b is depicted as a single component, it should be appreciated that the base stations 114a, 114b may include any number of interconnected base stations and / or network components.

[0034] The base station 114a may be part of the RAN 104, which may also include other base stations and / or network components (not shown), such as a base station controller (BSC), a radio network controller (RNC), relay nodes, etc. The base station 114a and / or the base station 114b may be configured to transmit and / or receive wireless signals within a specific geographic area called a cell (not shown). The cell may be further divided into cell sectors. For example, the cell associated with the base station 114a may be divided into three sectors. Thus, in one embodiment, the base station 114a may include three transceivers, that is, each transceiver corresponds to a sector of the cell. In another embodiment, the base station 114a may use multiple-input multiple-output (MIMO) technology, and thus multiple transceivers may be used for each sector in the cell.

[0035] The base stations 114a, 114b may communicate with one or more of the WTRUs 102a, 102b, 102c, 102d over an air interface 116, which may be any suitable wireless communication link (e.g., radio frequency (RF), microwave, infrared (IR), ultraviolet (UV), visible light, etc.). The air interface 116 may be established using any suitable radio access technology (RAT).

[0036] More specifically, as described above, the communication system 100 may be a multiple access system and may use one or more channel access schemes such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, etc. As an example, the base station 114a in the RAN 104 and the WTRUs 102a, 102b, 102c may implement a radio technology such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which may use Wideband CDMA (WCDMA) to establish the air interface 116. WCDMA may include communication protocols such as High Speed ​​Packet Access (HSPA) and / or Evolved HSPA (HSPA+). HSPA may include High Speed ​​Downlink Packet Access (HSDPA) and / or High Speed ​​Uplink Packet Access (HSUPA).

[0037] In another embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as Evolved UMTS Terrestrial Radio Access (E-UTRA), which may establish the air interface 116 using Long Term Evolution (LTE) and / or LTE-Advanced (LTE-A).

[0038] In other embodiments, the base station 114a and the WTRUs 102a, 102b, 102c may implement radio access technologies such as IEEE 802.16 (i.e., Worldwide Interoperability for Microwave Access (WiMAX)), CDMA2000, CDMA2000 1X, CDMA2000 EV-DO, Interim Standard 2000 (IS-2000), Interim Standard 95 (IS-95), Interim Standard 856 (IS-856), Global System for Mobile Communications (GSM), Enhanced Data rates for GSM Evolution (EDGE), GSM EDGE (GERAN), and the like.

[0039] As an example, Figure 1AThe base station 114b in the example may be a wireless router, a Home NodeB, a Home eNodeB, or an access point, and may use any appropriate RAT to facilitate wireless connectivity in a local area such as a business location, a residence, a vehicle, a campus, or the like. In one embodiment, the base station 114b and the WTRUs 102c, 102d may establish a wireless local area network (WLAN) by implementing a radio technology such as IEEE 802.11. In another embodiment, the base station 114b and the WTRUs 102c, 102d may establish a wireless personal area network (WPAN) by implementing a radio technology such as IEEE 802.15. In yet another embodiment, the base station 114b and the WTRUs 102c, 102d may establish a picocell or a femtocell by using a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, etc.). Figure 1A As shown, the base station 114b can be directly connected to the Internet 110. Thus, the base station 114b does not need to access the Internet 110 via the core network 106.

[0040] The RAN 104 may be in communication with a core network 106, which may be any type of network configured to provide voice, data, application, and / or voice over Internet Protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d. For example, the core network 106 may provide call control, billing services, mobile location-based services, pre-paid calling, Internet connectivity, video distribution, etc., and / or perform high-level security functions such as user authentication. Although Figure 1A Although not shown, it will be appreciated that the RAN 104 and / or the core network 106 may be in direct or indirect communication with other RANs, and that these RANs may employ the same RAT as the RAN 104 or different RATs. For example, in addition to being connected to the RAN 104, which may employ E-UTRA radio technology, the core network 106 may also be in communication with another RAN (not shown) employing GSM radio technology.

[0041] The core network 106 may also act as a gateway for the WTRUs 102a, 102b, 102c, 102d to access the PSTN 108, the Internet 110, and / or other networks 112. The PSTN 108 may include a circuit-switched telephone network that provides plain old telephone service (POTS). The Internet 110 may include a global system of interconnected computer networks and devices that use a common communication protocol, and the protocol may be the Transmission Control Protocol (TCP), the User Datagram Protocol (UDP), and the Internet Protocol (IP) in the TCP / IP Internet protocol suite. The networks 112 may include wired or wireless communication networks owned and / or operated by other service providers. For example, the networks 112 may include another core network connected to one or more RANs, which may use the same RAT as the RAN 104 or a different RAT.

[0042] Some or all of the WTRUs 102a, 102b, 102c, 102d in the communication system 100 may include multi-mode capabilities, that is, the WTRUs 102a, 102b, 102c, 102d may include multiple transceivers for communicating with different wireless networks over different wireless links. Figure 1A The illustrated WTRU 102c may be configured to communicate with the base station 114a, which may employ a cellular-based radio technology, and with the base station 114b, which may employ an IEEE 802 radio technology.

[0043] Figure 1B is a system diagram of an exemplary WTRU 102. Figure 1B As shown, the WTRU 102 may include a processor 118, a transceiver 120, a transmit / receive element 122, a speaker / microphone 124, a numeric keypad 126, a display / touchpad 128, a non-removable memory 130, a removable memory 132, a power source 134, a global positioning system (GPS) chipset 136, and other peripherals 138. It should be appreciated that the WTRU 102 may include any sub-combination of the foregoing components while remaining consistent with the embodiments.

[0044] The processor 118 may be a general purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP), a plurality of microprocessors, one or more microprocessors associated with a DSP core, a controller, a microcontroller, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) circuit, any other type of integrated circuit (IC), a state machine, and the like. The processor 118 may perform signal coding, data processing, power control, input / output processing, and / or any other functionality that enables the WTRU 102 to operate in a wireless environment. The processor 118 may be coupled to the transceiver 120, which in turn may be coupled to the transmit / receive element 122. Although Figure 1B The processor 118 and the transceiver 120 are depicted as separate components, however it should be appreciated that the processor 118 and the transceiver 120 may also be integrated into one electronic component or chip.

[0045] The transmit / receive component 122 may be configured to transmit or receive signals to and from a base station (e.g., base station 114a) via the air interface 116. For example, in one embodiment, the transmit / receive component 122 may be an antenna configured to transmit and / or receive RF signals. As an example, in another embodiment, the transmit / receive component 122 may be an emitter / detector configured to transmit and / or receive IR, UV, or visible light signals. In yet another embodiment, the transmit / receive component 122 may be configured to transmit and receive RF and light signals. It should be appreciated that the transmit / receive component 122 may be configured to transmit and / or receive any combination of wireless signals.

[0046] In addition, although Figure 1B 102 as a single component, but the WTRU 102 may include any number of transmit / receive components 122. More specifically, the WTRU 102 may employ MIMO technology. Thus, in one embodiment, the WTRU 102 may include two or more transmit / receive components 122 (e.g., multiple antennas) for transmitting and receiving radio signals via the air interface 116.

[0047] The transceiver 120 may be configured to modulate signals to be transmitted by the transmit / receive element 122 and to demodulate signals received by the transmit / receive element 122. As described above, the WTRU 102 may have multi-mode capabilities. Thus, the transceiver 120 may include multiple transceivers that allow the WTRU 102 to communicate via multiple RATs, such as UTRA and IEEE 802.11.

[0048] The processor 118 of the WTRU 102 may be coupled to a speaker / microphone 124, a numeric keypad 126, and / or a display / touchpad 128 (e.g., a liquid crystal display (LCD) display unit or an organic light emitting diode (OLED) display unit), and may receive user input data from these components. The processor 118 may also output user data to the speaker / microphone 124, the numeric keypad 126, and / or the display / touchpad 128. In addition, the processor 118 may access information from and store information in any suitable memory such as a non-removable memory 130 and / or a removable memory 132. The non-removable memory 130 may include a random access memory (RAM), a read-only memory (ROM), a hard disk, or any other type of memory storage device. The removable memory 132 may include a subscriber identity module (SIM) card, a memory stick, a secure digital (SD) memory card, and the like. In other embodiments, the processor 118 may access information from, and store data in, memory that is not physically located on the WTRU 102, such as, for example, on a server or a home computer (not shown).

[0049] The processor 118 may receive power from the power source 134, and may be configured to distribute and / or control power for use by other components in the WTRU 102. The power source 134 may be any suitable device for powering the WTRU 102. For example, the power source 134 may include one or more dry cell batteries (e.g., nickel-cadmium (Ni-Cd), nickel-zinc (Ni-Zn), nickel-metal hydride (NiMH), lithium-ion (Li-ion), etc.), solar cells, fuel cells, etc.

[0050] The processor 118 may also be coupled to the GPS chipset 136, which may be configured to provide location information (e.g., longitude and latitude) related to the current location of the WTRU 102. In addition to or in lieu of the information from the GPS chipset 136, the WTRU 102 may receive location information from a base station (e.g., base stations 114a, 114b) via the air interface 116 and / or determine its location based on the timing of signals received from two or more nearby base stations. It will be appreciated that the WTRU 102 may acquire location information using any suitable positioning method while remaining consistent with an embodiment.

[0051] The processor 118 may also be coupled to other peripheral devices 138, which may include one or more software and / or hardware modules that provide additional features, functionality, and / or wired or wireless connectivity. For example, the peripheral devices 138 may include an accelerometer, an electronic compass, a satellite transceiver, a digital camera (for photos or videos), a universal serial bus (USB) port, a vibration device, a television transceiver, a hands-free headset, modules, FM radio units, digital music players, media players, video game console modules, Internet browsers, and more.

[0052] Figure 1C Shown is a system diagram of an example RAN 104 and a core network 106 that may be in accordance with an embodiment. As noted above, the RAN 104 may employ an E-UTRA radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 104 may also be in communication with the core network 106.

[0053] The RAN 104 may include eNode-Bs 140a, 140b, 140c, however it will be appreciated that the RAN 104 may include any number of eNode-Bs while remaining consistent with an embodiment. Each of the eNode-Bs 140a, 140b, 140c may include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In one embodiment, the eNode-Bs 140a, 140b, 140c may implement MIMO technology. For example, the eNode-B 140a may use multiple antennas to transmit wireless signals to, and receive wireless signals from, the WTRU 102a.

[0054] Each eNodeB 140a, 140b, 140c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, uplink and / or downlink user scheduling, etc. Figure 1C As shown, the eNode-Bs 140a, 140b, and 140c may communicate with each other via an X2 interface.

[0055] Figure 1C The illustrated core network 106 may include a mobile management entity gateway (MME) 142, a serving gateway 144, and a packet data network (PDN) gateway 146. Although each of the aforementioned components are described as being part of the core network 106, it should be appreciated that any of these components may be owned and / or operated by an entity other than the core network operator.

[0056] The MME 142 may be connected to each of the eNode-Bs 140a, 140b, 140c in the RAN 104 via an S1 interface and may serve as a control node. For example, the MME 142 may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, performing bearer activation / deactivation processing, selecting a particular serving gateway during an initial attach of the WTRUs 102a, 102b, 102c, and the like. The MME 142 may also provide a control plane function for switching between the RAN 104 and other RANs (not shown) that employ other radio technologies, such as GSM or WCDMA.

[0057] The serving gateway 144 may be connected to each of the eNode-Bs 140a, 140b, 140c in the RAN 104 via an S1 interface. The serving gateway 144 may generally route and forward user data packets to / from the WTRUs 102a, 102b, 102c. The serving gateway 144 may also perform other functions such as anchoring a user plane during an inter-eNode-B handover, triggering paging processing when downlink data is available for the WTRUs 102a, 102b, 102c, managing and storing contexts of the WTRUs 102a, 102b, 102c, and the like.

[0058] The serving gateway 144 may also be connected to a PDN gateway 146, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices.

[0059] The core network 106 may facilitate communications with other networks. For example, the core network 106 may provide the WTRUs 102a, 102b, 102c with access to circuit-switched networks such as the PSTN 108 to facilitate communications between the WTRUs 102a, 102b, 102c and traditional land-line communications devices. For example, the core network 106 may include or be in communication with an IP gateway, such as an IP Multimedia Subsystem (IMS) server, which may serve as an interface between the core network 106 and the PSTN 108. In addition, the core network 106 may provide the WTRUs 102a, 102b, 102c with access to the networks 112, which may include other wired or wireless networks that are owned and / or operated by other service providers.

[0060] The other networks 112 may further be connected to a wireless local area network (WLAN) 160 based on IEEE 802.11. The WLAN 160 may include an access router 165. The access router 165 may include a gateway function. And the access router 165 may communicate with multiple access points (APs) 170a, 170b. The communication between the access router 165 and the APs 170a, 170b may be carried out via wired Ethernet (IEEE 802.3 standard) or any type of wireless communication protocol. The AP 170a wirelessly communicates with the WTRU 102d over an air interface.

[0061] As new applications for wireless cellular technologies continue to emerge, the importance of supporting higher data rates, lower latency, and massive connections continues to grow. For example, support for enhanced mobile broadband (eMBB) communications, ultra-reliable low latency communications (URLLC), and massive machine type communications (mMTC) continues to grow. When multiple applications with different goals can be supported, it becomes increasingly important to develop efficient means for multiplexing different services within the radio access network.

[0062] Wireless communication systems using orthogonal frequency division multiplexing (OFDM) waveforms, such as 3GPP LTE and IEEE 802.11, may use fixed parameter configurations for OFDM waveforms across the allocated system bandwidth. However, as new applications and usage scenarios for wireless cellular technologies continue to emerge, the use of hybrid parameter configurations may be a more attractive way to support different services within the same channel. As used herein, parameter configuration may refer to one or more of the following: subcarrier spacing, OFDM symbol length, or cyclic prefix (CP) overhead. A resource element may refer to a resource defined by one subcarrier and one symbol.

[0063] Figure 2 Schematic diagram showing an example of in-band use of hybrid parameter configurations within waveforms operating within adjacent partitions of a channel bandwidth. As shown in the example within schematic diagram 200, three reference configurations may be used by three different types of communications. For example, a first parameter configuration 210 may be used for eMBB and include resource elements, such as resource element 220, having a first subcarrier spacing and a first OFDM symbol duration. Further, a second reference configuration 230 may be used for URLLC and include resource elements, such as resource element 240, which may have a second subcarrier spacing and a second OFDM symbol duration. In addition, a third reference configuration 250 may be used for mMTC and include resource elements, such as resource element 260, which have a third subcarrier spacing and a third OFDM symbol duration.

[0064] OFDM waveforms can have high side lobes in the frequency domain as well as high out-of-band (OOB) emissions. If OFDM signals with mixed waveform parameter configurations are transmitted adjacent to each other in the same frequency channel, inter-parameter configuration interference may occur. In the spectral domain, the side lobes of one parameter configuration may decay slowly with frequency (as a function of 1 / f) and may interfere with subcarriers of other parameter configurations in adjacent partitions. This interference may severely degrade the signal-to-noise ratio (SNR) in adjacent partitions, thereby limiting system performance. For example, interference may limit the achievable data rate.

[0065] In other scenarios, the system may operate in frequency selective channels, whereby there may be significant SNR variability within the system bandwidth. Additionally, some channels may experience more severe interference than other portions of the channel. Considering fifth generation (5G) applications, relying on traditional scheduling to mitigate this SNR variability is insufficient for this use case.

[0066] In other cases, the system may operate in a frequency-selective channel with a non-negligible delay spread. In these scenarios, when there is a transition or interruption at the beginning of a subframe or transmission time interval (TTI), the first symbol of the transmission may be affected by interference and the received signal-to-noise-to-interference (SINR) ratio for the symbol may be reduced. In an example, the first symbol may be a first OFDM symbol or a first discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-s-OFDM) symbol.

[0067] Therefore, when hybrid OFDM waveform parameter configuration is used in adjacent partitions of the same channel, or when significant SNR variability is encountered within the system bandwidth, some solutions are needed to improve system performance and spectral efficiency. The embodiments, examples and solutions described herein can be applied to scenarios where SNR is unevenly distributed within the channel bandwidth (including but not limited to hybrid parameter configuration). Examples and embodiments are described herein for downlink (DL) transmission, but those skilled in the art will appreciate that DL transmission can also be used in non-limiting examples of application. Accordingly, the examples and embodiments can be applied to uplink (UL), sidelink (SL), etc., and are still consistent with the solutions described herein. In the examples and embodiments described herein, the terms UL and / or SL can be replaced with DL, and are still consistent with the solutions described herein. In some embodiments and examples, the terms downlink control information (DCI), control information, control channel, and control message can be used interchangeably, and are still consistent with the solutions described herein.

[0068] Methods, devices, and systems for improving system performance and spectral efficiency when hybrid OFDM waveform parameter configurations are used in adjacent sectors of a single channel are discussed herein. Exemplary methods, devices, and systems may include mapping a lower order modulation for a first resource near a sector edge, and mapping a higher order modulation for a second resource near a sector center and away from the sector edge.

[0069] In a specific example, the WTRU may map a first set of bits in a first codeword to a higher order modulation scheme and map a second set of bits in the first codeword to a lower order modulation scheme. Thereafter, the WTRU may transmit the first codeword. Thereafter, the eNodeB may receive the first codeword. Further, the WTRU may determine that data of the first codeword will be retransmitted on a second codeword, which may contain the same number of bits as the first codeword. Thereafter, the WTRU may map the first set of bits in the second codeword to a lower order modulation scheme and map the second set of bits in the second codeword to a higher order modulation scheme. The first set of bits in the second codeword may contain the same number of bits as the second set of bits in the first codeword and may contain at least a subset of the data within the first set of bits of the first codeword. Thereafter, the WTRU may transmit the second codeword. Thereafter, the eNodeB may receive the second codeword.

[0070] Additional further examples may include assigning a first codeword to a spatial layer, wherein the first codeword is mapped in the frequency domain to a first resource block (RB) located at an edge of a partition, and wherein the first codeword is configured to use a robust modulation and coding scheme (MCS). Additional examples include assigning a second codeword to the spatial layer, wherein the second codeword is mapped in the frequency domain to a second RB located toward the center of the partition, and wherein the second codeword is configured to use a more aggressive MCS; and multiplexing the first codeword and the second codeword in a frequency division multiplexing (FDM) manner.

[0071] Further, methods, apparatus, and systems are discussed herein for improving system performance and spectral efficiency when hybrid OFDM waveform parameter configurations are used in adjacent sectors of a single channel. Examples may include performing demodulation reference signal (DMRS) based beamforming at the band edge to minimize interference in the direction of adjacent served WTRUs and maximize the transmission efficiency of the served WTRU.

[0072] In addition, methods, devices and systems for reducing the impact of interference on the accuracy of channel estimation in a system with a hybrid parameter configuration are provided herein. Examples may include introducing additional power offset settings for band edge transmissions; using a different set of power settings for reference signal demodulation required for channel estimation; and using power boosting for reference signals on reference resource elements (REs) located at the band edge.

[0073] Additionally, methods, apparatus, and systems for synchronized downlink transmissions for a hybrid parameter configuration system with flexible channel bandwidth are discussed herein. Examples may include using a common parameter configuration region to carry a synchronization signal (SS), wherein the common parameter configuration region is accessible to a WTRU configured using a first parameter and a WTRU configured using a second parameter.

[0074] In addition, methods, devices, and systems for improving uplink transmission performance in a hybrid parameter configuration system are discussed herein. Examples may include using different frequency resources from different antennas to transmit uplink control channels. Examples may include reducing the coding rate of control information transmitted in a partition edge region. Examples may include transmitting control information on resources that are not mapped to a partition edge.

[0075] Other examples discussed herein are methods, apparatus, and systems for reducing uneven SINR distribution across a subframe. Examples may include configuring the first one or more symbols of the subframe to use a lower order modulation and configuring the remaining symbols of the subframe to use a higher order modulation.

[0076] Examples of variable modulation orders that may be included in a resource assignment are described below. In one example, mapping variable modulation orders for a single transport block (TB) assignment is disclosed.

[0077] Figure 3 300 is a diagram illustrating an example of using variable modulation order within a TB. As shown in the example in diagram 300, for a single TB assignment to a WTRU, the modulation mapping may use a lower order mapping for resources near the edge of a partition. Additionally, a higher order modulation may be used for resources near the center of the partition and away from the edge of the partition, thereby mitigating SINR loss at the edge of the partition.

[0078] exist Figure 3In the example shown, within a resource assignment for a codeword (CW) transmission (which may be transmitted on a TB on a first partition 310 having a first parameter configuration), resources near the partition edge (such as RB 334) may use lower order modulation to mitigate SINR loss at the partition edge. In one example, the low order modulation may be quadrature phase shift keying (QPSK) at the partition edge. If channel conditions permit, resources further away from the partition edge (such as RB 332) may be assigned higher order modulation, such as 16-quadrature amplitude modulation (QAM) or 64-QAM. Similarly, for a resource assignment for a CW (which may be transmitted on a TB on a second partition 360 having a second parameter configuration), resources near the partition edge (such as RB384) may use lower order modulation, while other RBs 382 away from the partition edge may use higher order modulation.

[0079] like Figure 3 As shown, a graph of frequency on the horizontal axis versus SINR on the horizontal axis can be plotted. This graph can show that resources near the edge of the partition on both sides of the partition can have a lower SINR than resources far from the edge of the partition. This reduction in SINR may be due to interference caused by parameter configuration partitions. For example, RB 334 with SINR curve 350 and RB 384 with SINR curve 355 may have a lower SINR than RB 332 with SINR curve 320 and RB 382 with SINR curve 370. A similar graph (not shown) can be created, which is plotted for Figure 3 This graph can similarly show that resources close to the partition edge on both sides of the partition can have lower SINR than resources far from the partition edge.

[0080] Figure 4 400 is a block diagram showing variable modulation order mapping for single-layer single-antenna transmission. Mapping different modulation orders to different RBs as described in the above example can be implemented for single-layer transmission using the example shown in block diagram 400. Block diagram 400 also shows an example of mapping different modulation orders to different RBs for single-antenna transmission.

[0081] For example, input bits may be input to a channel decoding block 410 for encoding. The coded bits available at the output of the channel decoding block 410 may be mapped to modulation symbols using a "modulation mapper". For example, a subset of coded bits may be processed by a high-order modulation mapper block 430 and mapped to the IFFT input of subcarriers near the center 455 of a partition when output by a resource element mapper 440. The remaining subset of coded bits may be processed by a low-order modulation mapper block 420 and mapped to the IFFT input of subcarriers near the edge 450 of a partition when output by a resource element mapper 440. Thereafter, an OFDM symbol generator 470 may receive the mapped bits and generate a corresponding OFDM symbol.

[0082] Figure 5 Schematic diagram showing the change of modulation mapping for retransmission. When a transport block needs to be retransmitted, the transmitter may change the mapping order of the coded bits. In one example, the transmitter may change the mapping order of the coded bits so that potential errors are randomly distributed over the transport block. For example, a subset mapped to the edge of a partition using a lower order modulation scheme for a new transmission may be mapped to the middle of a partition using a higher order modulation scheme for retransmission (which may be away from the partition edge). In this way, during retransmission, different subsets of transport block bits may encounter lower SINRs (which may be located at the edge of a partition) than the low SINR suffered by the bit subset during the first transmission. This may cause bit errors to be randomly distributed over the transport block, which may increase diversity gain. In this way, different bits may be erroneous in the first transmission compared to the retransmission. The new transmission may be a codeword transmission, and the retransmission may be a codeword retransmission.

[0083] In the example shown in the schematic diagram 500, for new data transmission, the first N1 bits 520 of the coded block of the codeword 510 may be mapped to a higher order modulation scheme, and the last N-N1 bits 520 of the coded block of the codeword 510 may be mapped to a lower order modulation scheme. For retransmission, for example, when the same amount of resources as the new data transmission is allocated, the first N-N1 bits 560 of the coded block of the codeword 550 may be mapped to a lower order modulation scheme, and the last N1 bits 570 may be mapped to a higher order modulation scheme.

[0084] In this way, the number of bits using each modulation scheme remains the same in both a new data transmission of a codeword and a retransmission of the codeword. For example, N-N1 bits 530 and N-N1 bits 560 comprise the same number of bits and may be transmitted using a lower order modulation scheme. Similarly, N1 bits 520 and N1 bits 570 comprise the same number of bits and may be transmitted using a higher order modulation scheme. The change in the sequence processing of the coded bits (e.g., a high order modulation followed by a low order modulation for a new data transmission and a low order modulation followed by a high order modulation for a retransmission) may be predefined or signaled in the DCI.

[0085] Figure 6 Flowchart for an example of changing modulation mapping for retransmission. In the example shown in flowchart 600, a WTRU may map a first set of bits in a first codeword to a higher order modulation scheme and map a second set of bits in the first codeword to a lower order modulation scheme 620. Thereafter, the WTRU may transmit the first codeword 630. Thereafter, an eNodeB may receive the first codeword. Further, the WTRU may determine that data of the first codeword will be retransmitted on a second codeword 640, which may contain the same number of bits as the first codeword. Thereafter, the WTRU may map a first set of bits in the second codeword to a lower order modulation scheme and map a second set of bits in the second codeword to a higher order modulation scheme 650. The first set of bits in the second codeword may contain the same number of bits as the second set of bits in the first codeword and may contain at least the set of data in the first set of bits in the first codeword. Thereafter, the WTRU may transmit the second codeword 660. Thereafter, the eNodeB may receive the second codeword.

[0086] In a further example, the WTRU may receive an assignment message from an eNodeB including information about a partition decision and resource assignment. Ultimately, the WTRU may determine at least two bandwidth partitions for wireless transmission based on the assignment message, wherein each of the at least two partitions has a different symbol period, a different subcarrier spacing, or both. Further, the WTRU may assign RBs of the at least two partitions based on the assignment message, wherein RBs of a partition that is close to an adjacent partition on at least one of time and frequency resources are assigned a lower order modulation scheme, and wherein the first codeword is transmitted using the assigned RBs. In an example, the first partition may have a first parameter configuration, and the second partition may have a second parameter configuration.

[0087] Further, a base station (such as an eNodeB) may determine the data of the first codeword to be retransmitted based on the low SINR rate of the transmitted first codeword. In one example, the eNodeB may make the determination based on other considerations in addition to or in lieu of the SINR rate. The eNodeB may transmit a message to the WTRU including an instruction to retransmit the data of the first codeword. Thereafter, the WTRU may determine that the data of the first codeword to be retransmitted is based on the message received from the eNodeB. In addition, the bit mapping of the codeword may be based on at least one of: a predefined process, a process dynamically signaled, and a process signaled within the DCI.

[0088] In another example, the eNodeB may map a first set of bits in a first codeword to a higher order modulation scheme and map a second set of bits in the first codeword to a lower order modulation scheme. Thereafter, the eNodeB may transmit the first codeword. Thereafter, the WTRU may receive the first codeword. Further, the eNodeB may determine that data of the first codeword will be retransmitted on a second codeword, which may contain the same number of bits as the first codeword. Thereafter, the eNodeB may map the first set of bits in the second codeword to a lower order modulation scheme and map the second set of bits in the second codeword to a higher order modulation scheme. The first set of bits in the second codeword may contain the same number of bits as the second set of bits in the first codeword and may contain at least a subset of the data in the first set of bits in the first codeword. Thereafter, the eNodeB may transmit the second codeword. Thereafter, the WTRU may receive the second codeword.

[0089] In an additional example, an eNodeB may determine at least two bandwidth partitions for wireless communication, wherein each of the at least two bandwidth partitions has a different symbol period, a different subcarrier spacing, or both. Further, the eNodeB may assign RBs of the at least two partitions, wherein RBs of a partition that is close to an adjacent partition in at least one of time and frequency resources are assigned a lower order modulation scheme, and wherein the first codeword is transmitted using the assigned RBs. In an example, the first partition may have a first parameter configuration and the second partition may have a second parameter configuration. In an example, the eNodeB may generate and transmit an assignment message to the WTRU, the assignment message may include instructions regarding the partition determination and resource assignment.

[0090] In addition, the eNodeB may determine that data of the first codeword is to be retransmitted based on a low SINR rate of the transmitted first codeword. In an example, the eNodeB may make the determination based on other considerations in addition to or in lieu of the SINR rate. Thereafter, the eNodeB may retransmit the data on the second codeword. In addition, the bit mapping of the codeword may be based on at least one of: a predefined process, a dynamically signaled process, and a process signaled within the DCI.

[0091] The following example may include a measure for variable modulation order on a per-TB basis. In an example, if the base station assigns both partition edge and partition center resources (such as RBs) for a single TB transmission to the WTRU, the base station may select the MCS based on the channel state report or more specifically the channel quality indicator (CQI) reported by the user. The granularity of the reported CQI may depend on the channel state report type, such as aperiodic vs. periodic, wideband vs. WTRU selected.

[0092] For example, the WTRU may provide a single CQI report based on the entire cell bandwidth, as in the case of aperiodic wideband reporting. In another example, the WTRU may divide the total system (e.g., component carrier) bandwidth into several parts and provide a wideband CQI for each bandwidth part and the best RB subset (or subband) within the bandwidth part. In yet another example, the WTRU may choose to report CQI only for a certain set of subbands. The subband selection may be WTRU selected (in which case these subbands may be its best subbands) or network configured.

[0093] If the base station assigns both partition edge and partition center resources (RBs) for a single TB transmission from a WTRU, the base station may select the MCS based on channel state reports or channel measurements. The base station may measure the channel using reference signals transmitted by the WTRU. For example, the base station may measure a sounding reference signal transmitted by the WTRU. The transmission parameters of reference signals transmitted in different parts of a partition may be different. For example, a reference signal transmitted on the edge may have a higher power than a reference signal transmitted in the middle of a partition.

[0094] In addition to channel state reports and / or measurements, the base station may also utilize various other parameters when determining the modulation order selection for each RB or RB group. Such other parameters may include, for example, the set of available resources and the amount of data that needs to be transmitted. Depending on the availability and granularity of the above-mentioned CQI reports, the base station may flexibly utilize a wide range of CQI reports and the total number of available resources (RBs) when selecting the modulation order for each resource set (e.g., partition edge or partition center) of the TB. The CQI report may include, for example, broadband and best sub-band CQI for each bandwidth portion.

[0095] For example, if the assigned RB groups within each partition have similar CQI values, the base station may choose to utilize the same modulation order for the partition edge and partition center resources. This may occur if the assigned resources within each partition are within the optimal sub-band described above, or if the wideband CQI reported for each partition is utilized and the reported wideband CQI for each partition is similar.

[0096] In other cases, such as when resource availability is not a constraining factor, or if the base station has only a very small amount of data to transmit, it may select a lower, more conservative MCS for the zone edge and zone center resources. In this case, the MCS may be selected based on the CQI of the boundary edge resources.

[0097] The following examples may include signaling a variable modulation order to the WTRU. Additionally, the following examples may include calculating an assigned TBS using a variable modulation order.

[0098] A WTRU or group of WTRUs may be semi-statically configured (e.g., via higher layer signaling) with one or more of the following parameters. In one example, a parameter may be a region in the frequency domain, such as an RB, where a particular modulation type (e.g., QPSK) may be used. A parameter may be a particular modulation type to be used, such as QPSK. A parameter may be enabling or disabling the use of multiple modulation types for a transport block.

[0099] Using control signaling (such as DCI), a base station may dynamically signal one or more of the following information to a WTRU or group of WTRUs. For example, information from which the WTRU may determine a coding rate or a transport block size (TBS) may be signaled by the base station. In another example, information from which the WTRU may determine at least one modulation type may be signaled. In yet another example, information from which the WTRU may determine RBs or resources for an assigned TB may be signaled.

[0100] For example, when a single modulation order is used for a TB, existing L1 / L2 control signaling may be used to inform the WTRU of various transmission parameters. The transmission parameters may include, for example, MCS and RB allocation. For example, in the case where the assigned partition center and partition edge resources are not contiguous, DCI format 1 may be used, while in the case where the assigned resources are contiguous, the more compact DCI format 1A may be used.

[0101] Figure 7FIG. 7 is a diagram showing an example of signaling an offset for modulation order selection for sector edge resources. In the example shown in diagram 700, when the base station selects two modulation orders for the resources, the control information may carry MCS information for sector center resources 710. The modulation order information for sector edge resources 750 may be signaled in the same message as an offset for the MCS information for the center resources. In one example, Figure 7 As shown, the offset may be represented (e.g., bitmapped) using an N-bit value, such that a zero value for the offset indicates a constant modulation order within a TB, while a non-zero value points to a specific row of a modulation table for a PDSCH to be used for partition edge resources. For example, the MCS information signaled for the partition center resource 710 may include a modulation order of 4 and a code rate of approximately 0.4. Further, the offset of the modulation order signaled for the partition center resource 750 may include a modulation order of 2 and a code rate of approximately 0.4. In one example, a standard mapping of MCS to code rate and modulation type may be used.

[0102] In another example, when the base station selects two different modulation orders for resources within the same TB, the base station may use L1 / L2 control signaling to signal the MCS of resources mapped to the center or partition and the MCS of resources mapped to the edge of the partition. In an example, the resource may be a resource block or a resource block group.

[0103] In another example, the base station may signal the MCS of the resources mapped to the center of the partition, and may signal the modulation order and coding rate of the resources mapped to the edge of the partition. The base station may signal the MCS of the center RBs, and if, for example, the WTRU is semi-statically configured to use a specific modulation type in a specific region in the frequency domain, the base station may only signal the coding rate of the pre-configured RBs. In this case, the WTRU may use the resource allocation to autonomously determine whether any of the configured RBs are in the semi-statically configured region. If so, it may use the semi-statically configured modulation order to map / unmap symbols, calculate TBS for forward error correction (FEC) encoder / decoder processing, etc.

[0104] In another example, a DCI carrying MCS signaling for center RBs and for edge RBs may signal resource block allocations.For example, the DCI may indicate the number and location of partition edge RBs that may be configured for lower order modulation.

[0105] When the WTRU is dynamically signaled or semi-statically configured to use multiple different modulation orders within a transport block, one or more of the following usable parameters may apply. The WTRU may determine whether to use one modulation type or multiple modulation types to transmit data in the UL or receive data in the DL. In one example, the multiple modulation types may be two modulation types. The WTRU may make the determination based on at least one of: whether the use of multiple modulation types has been enabled, and the location (e.g., frequency location) of the RB. For example, the WTRU may use multiple modulation types when the frequency locations of some allocated RBs are at a specific location. The specific location may be the edge of the frequency band, within x kilohertz (kHz) from the edge of the frequency band, or configured by higher layer signaling.

[0106] The WTRU may use at least one of the transmission parameters that may be signaled to determine the transport block size, for example, for the FEC encoding chain, the decoding chain, or both. The transmission parameters may include at least one of the following: an MCS for a first set of RBs (e.g., center RBs), an MCS for a second set of RBs (e.g., edge RBs), a modulation order for the second set of RBs, a coding rate corresponding to bits mapped to the second set of RBs, an offset of the coding rate of the second set of RBs relative to the coding rate of the first set of RBs, and a resource block allocation. The resource block allocation may be contiguous, and the WTRU may autonomously determine which of the allocated RBs may be located in the second set of RBs. In one example, the second set of RBs may be edge RBs. The resource block allocation may be non-contiguous, and the WTRU may use different indications for RB allocations for the first set of RBs and the second set of RBs.

[0107] For example, if the base station signals the MCS of the first RB set, the MCS of the second RB, and the RB allocation, the WTRU can determine the number of RBs in the first set, the number of RBs in the second set, and use a predefined mapping to determine the transport block size that can be supported by the first RB set and the transport block size that can be supported by the second RB set, thereby calculating the effective TBS that can be used.

[0108] In another example, if the base station signals the MCS of the first RB set and the modulation order of the second RB set, the WTRU may determine the number of RBs in the first set, the number of RBs in the second set, and use a predefined mapping to determine the transport block size that the first RB set can support. The WTRU may then determine the appropriate coding rate supported by the first RB set, and may use the first coding rate in combination with the modulation type and number of RBs in the second set to calculate the TBS that can be supported in the second RB set. The TBS of the second RB set may then be selected from the mapping table as the closest TBS that is less than the previously calculated value. Those skilled in the art will appreciate that other examples of how the WTRU determines the total TBS that can be used jointly for the first and second RB sets are also feasible and still consistent with the present invention.

[0109] In the examples and embodiments described herein, MCS may refer to a modulation and coding set that may be used to signal the modulation order and parameters that the WTRU may use to obtain the TBS and / or coding rate. The parameter may be, for example, I_TBS. The MCS is used in a non-limiting manner only. Other information may be used in place of the MCS to signal the modulation order, coding rate, and / or TBS to the WTRU and still be consistent with the examples described herein.

[0110] In an example, FDM of multiple codewords within a TTI may be performed. In one example, for example, when a large amount of data needs to be transmitted to a node, a large number of RBs may need to be assigned to the transmission, and two codewords may be assigned to the same spatial layer and multiplexed in an FDM manner. In various examples such as the following, a large amount of data may need to be transmitted to a node: DL from a base station to a WTRU, UL from a WTRU to a base station, or a WTRU to WTRU link. In one example, a first codeword may be mapped in the frequency domain to an RB at the edge of a partition and may be configured to use a robust MCS. This may mitigate SNR loss due to interference between parameter configurations. A second codeword assigned to the same WTRU or node may be mapped in the frequency domain to an RB located toward the center of a parameter configuration partition and may be configured to use a more aggressive MCS, which may help achieve higher throughput. The more aggressive MCS may include, for example, higher order modulation, higher order coding rates, and the like.

[0111] Figure 8 800 is a diagram illustrating an example of FDM transmission of two codewords on a single layer. As shown in the example in diagram 800, two adjacent partitions may be configured using different parameters. In this example, a first WTRU may be assigned data in a first partition 810 configured using a first parameter, while a second WTRU may be assigned data in a second partition 860 configured using a second parameter. At the boundary between the partitions 810, 860, the SINR may be reduced. Figure 8This reduction is shown in FIG. 1 , which shows a graph of frequency on the horizontal axis versus SINR on the horizontal axis can be plotted similar to Figure 3 As shown. This drawing shows that the resources closest to the partition edges on both sides of the partition have a lower SINR than the resources far from the partition edges. The reduction in SINR is caused by the interference caused by the parameter configuration partition. For example, codeword B 840 with SINR curve 850 and codeword C 880 with SINR curve 855 may have a lower SINR than codeword A 830 with SINR curve 820 and codeword D 890 with SINR curve 870. A similar drawing (not shown) of the time variation of SINR for codewords 830, 840, 880, and 890 can also be created. This drawing can similarly show that resources closer to the partition edges on both sides of the partition have a lower SINR than resources far from the partition edges.

[0112] like Figure 8 As shown, the first WTRU may be assigned codeword B 840 that may be mapped to an RB near a partition boundary in the frequency domain and may use a robust MCS selection. The robust MCS selection may be, for example, a low order modulation (such as QPSK) and a low coding rate. In the same time resources (such as within the same TTI), the first WTRU may also be assigned codeword A 830 that is mapped to the center of the partition in the frequency domain and may use an aggressive MCS selection. The aggressive MCS selection may be, for example, a higher modulation order (such as 16-QAM, 64-QAM or higher) and a high coding rate. Similarly, for a second WTRU that may be assigned data configured using a second parameter, codeword C 880 may be mapped near a partition boundary and may use a robust MCS selection. Codeword D 890, which may also be assigned to the second WTRU, may be mapped closer to the center of the partition and may use a more aggressive MCS selection. A control channel may use a more robust MCS selection. For example, a first control channel may use control region resources within the first partition 825 and may use a more robust MCS selection. Additionally, a second control channel may use control region resources within the second partition 875 and may similarly use a more robust MCS selection.

[0113] In one example, the parameters of the second codeword may be obtained from the parameters of the first codeword. For example, the WTRU may be semi-statically configured to use a certain number of RBs located within a certain portion of the system bandwidth. The certain portion of the system bandwidth may be, for example, 4 RBs located at the edge of the band. These resources may be used to map the second codeword, and in addition to the control information for the first codeword, the base station may only need to signal the MCS of the second codeword.

[0114] In one example, some portions of the channel bandwidth may be allocated to retransmissions of codewords that were not successfully received. For example, the edges of channel partitions (where the partitions may be configured for transmission of waveforms with different parameter configurations) may be allocated for retransmissions. The size of the partition edges may be determined by a central controller (such as a base station) and may be signaled, configured, or both within a control channel. The size of the partition edges may be expressed in Hertz (Hz), number of subcarriers, number of resource blocks, or other metrics.

[0115] In another example, some channel bandwidth portions may be allocated for additional bits of the transmission codeword. The information bits of the data stream may be encoded and then processed by a rate matching operation (which may select certain bits from the output of the channel encoder), where the selected bits may be further processed for transmission. A channel bandwidth partition may be further divided into two or more sub-partitions. For example, one or more partition edges may constitute a sub-partition. The number of bits at the output of the rate matching block may be determined based on the resources available within a subset of sub-partitions.

[0116] For some WTRUs, the rate matching process may be configured to generate additional bits that may be transmitted within those resources of other sub-partitions. For example, if the channel bandwidth is divided into 2 partitions (e.g. Figure 8 ), each partition may be further divided into 2 sub-partitions, where one of the sub-partitions may consist of resources at the partition edge. In one example, the partition edge may have N subcarriers, and the remainder may have M subcarriers. A rate matching operation may be performed so that the number of bits at the output of the rate matching may fit into the M subcarriers. In one method, the rate matching operation may output additional bits that may fit into the N subcarriers.

[0117] In an example, a hybrid cell-specific reference signal (CRS) and MDRS based transmission mode may be used. In transmissions with hybrid parameter configurations, inter-parameter configuration interference may affect the transmission quality of a given service allocation, especially at the band edge or partition edge, where there is a transition from one parameter configuration to another. The resulting interference may be mutual, however, a service with a larger subcarrier spacing may have a greater impact on a service with a smaller subcarrier spacing.

[0118] Fig. 9900 is a diagram showing an example of an interference model for a band edge. As shown in the example in the diagram 900, there is a band edge or partition edge between two services. One way to compensate for the loss incurred at the band edge is to utilize WTRU specific beamforming, that is, perform DMRS based beamforming on the band edge regardless of the transmission mode of the rest of the band. Beamforming on the band edge can be done by two services, thereby minimizing interference 970, 980 in the direction of the other service's WTRU and maximizing the transmission efficiency of the service's own WTRU. Fig. 9 An exemplary interference model for two adjacent services (ie, S1 and S2, with different subcarrier spacings) is shown.

[0119] for Fig. 9 For the exemplary scenario shown, the following transmit beamforming process may be designed. WTRU1 910 and WTRU2 920 may perform channel measurements to provide implicit or explicit information. 11 , there may be a channel response for WTRU1 910 for its desired service S1. The desired service S1 may be transmitted on parameter configuration 1. 21 , there may be a channel response for WTRU1 910 from interfering service S2. Service S2 may be transmitted on parameter configuration 2. 12 On the channel response H, there may be a channel response for WTRU 2920 from interfering service S1 transmitted on parameter configuration 1. 22 , there may be a channel response for WTRU2 920 for desired service S2 transmitted on parameter configuration 2. In some cases, such as when the difference between subcarrier spacings is not large, it may be assumed that H1 = H 11 =H 21 and H2=H 12 =H 22 .

[0120] By using the measurements provided by the WTRU, the base station can perform beamforming to: minimize the impact of service Si on other services; maximize the SNR of the expected transmission of service Si; minimize the interference caused by service Si while limiting the SNR of the expected transmission of service Sj to above a certain threshold; or maximize the expected transmission of service Si while limiting the interference caused by service Sj to below a certain threshold.

[0121] The base station may perform beamforming to benefit both WTRUs, or, for example, to maximize the expected S1 of WTRU1 910 while minimizing interference from S2. Different beamforming mechanisms may be used, and an exemplary method may be based on maximizing the signal-to-leakage-to-noise (SLNR) ratio,

[0122]

[0123] Among them, M1, and w1 represent the number of antennas at WTRU1 910, the noise variance, and the beamforming vector used by S1, respectively. The beamforming vector w1 may be defined as:

[0124] w1∝max.eigenvector((M1σ1 2 I+H2 H H2) -1 H1 H H1) Equation (2) It should be noted that a similar solution can be derived for w2.

[0125] In another example, WTRU1 910 may use receive beamforming to mitigate the effects of interference on the band edge. In order to design receiver beamforming, WTRU1 910 may need the direction of the interference generated by another S2. A way to estimate the spatial direction of interference on S1 may be as follows. WTRU1 910 may be configured to perform CSI-RS measurements on the inner sub-bands immediately adjacent to the band edge. The base station may stop transmission on the band edge of S1. WTRU1 910 may now be configured to perform CSI-RS measurements on the band edge of S1. WTRU1 910 may compare the measurements from the first step with the measurements of the third step to estimate the direction of the beamforming vector for the adjacent interfering band.

[0126] In a further example, the WTRU may be configured to perform CSI-RS measurements at the band edge. The WTRU may report the level of interference observed to estimate the CQI.

[0127] In an example, power boosting for REs may be used. The power of cell-specific reference signals may be adjusted based on the selectivity and quality of the channel, enabling accurate channel estimation. In LTE, the ratio between CRS and data REs may be a cell-specific parameter that may be changed to enable better channel estimation.

[0128] In a system with a mixed parameter configuration, the transmission of a system with a wider subcarrier spacing may have a greater impact on the performance of a system with a smaller subcarrier spacing, thereby causing interference on both the data signal and the reference signal. One way to reduce the interference to the accuracy of the channel estimation may be to introduce an additional power offset setting for the band edge transmission. Therefore, the WTRU may be configured to use a different set of power settings for the demodulation of the reference signals required for channel estimation. The power boost of the reference signal may be applied to all reference REs located at the band edge. Therefore, the WTRU may be configured to use a different set of power settings for demodulation and appropriate use of the reference REs located at the band edge and inner RBs.

[0129] In another example, another way to reduce the impact of interference may be to apply a power offset to all REs at one or more RBs located at the edge of the band. The increased allocated power from the band edge power boost may be supported from the power of the inner RBs that are not interfered with by neighboring services. Therefore, the WTRU may be configured to use a different set of power settings to demodulate all REs located at the edge of the band and at the inner RBs. In the case of additional power boosting for reference signals, the WTRU may need to apply additional power offsets to demodulate the reference REs. The power boosting technique may be applicable to any node (including base stations, WTRUs, etc.) that is transmitting on a band partition with variable quality.

[0130] In an example, downlink synchronization may be used to support hybrid parameter configurations and flexible channel bandwidth. In a cellular system, synchronization signals are generally used by the WTRU to achieve frame, subframe, time slot and symbol synchronization, identify the channel center, and extract the physical (PHY) layer cell identity (ID). In LTE, there may be two types of synchronization signals: the primary synchronization signal (PSS) and the secondary synchronization signal (SSS). The PSS may be used to achieve subframe, time slot and symbol synchronization in the time domain, identify the channel bandwidth center in the frequency domain, and infer a pointer to one of three physical layer cell identifiers (PCIs). The SSS may be used to achieve radio frame synchronization and infer a pointer to one of 168 physical layer cell identifier (PCI) groups. These synchronization signals may be placed in a set of resource elements located at the center of a channel with a certain rate.

[0131] A system capable of deploying different OFDM parameter configurations may need to synchronize with some WTRUs within the network, thus requiring a synchronization signal (SS) and a corresponding synchronization mechanism. Since the SS may be used by WTRUs with mixed parameter configuration capabilities, it may be desirable to use one of the parameter configurations for the SS, which may be referred to as a common parameter configuration. The resources carrying the SS may also carry other signals that need to be broadcast to all WTRUs or groups of WTRUs. The other signals may include, for example, cell-specific reference signals. The common parameter configuration may also carry WTRU-specific signals for stable transmission and reception.

[0132] Fig. 10A and 10B 1000 is a signaling diagram showing an example of arranging synchronization signals within a hybrid parameter configuration time-frequency grid. The example within the signaling diagram 1000 is shown on a grid with the horizontal axis being frequency, the vertical axis being time, and the center frequency of the channel being shown as fc. Specifically, Fig. 10A and 10B The examples shown show two possible ways of allocating resources for signals (including PSS and SSS) using a common parameter configuration and its coexistence with other parameter configurations within a channel. Although only two other parameter configurations with symmetric allocation patterns are shown, in general, many different parameter configurations and patterns may exist.

[0133] like Fig. 10A As shown in the example in FIG. 1 , the first parameter configuration 1010A may be used by the first WTRU group in the first portion of the channel bandwidth, and the second parameter configuration 1030A may be used by the second WTRU group in the second portion of the channel bandwidth. In one example, the first parameter configuration 1010A may be used by the URLLC WTRU, and the second parameter configuration 1030A may be used by the mMTC WTRU. The common parameter configuration 1020A may be used by the SSS 1050A and the PSS 1060A. In one example, the common parameter configuration 1020A may be used in a third portion of the channel bandwidth between the first portion of the channel bandwidth and the second portion of the channel bandwidth. In one example, the common parameter configuration 1020A may be the same parameter configuration as one of the first parameter configuration 1010A and the second parameter configuration 1030A. In another example, the common parameter 1020A may be a third parameter configuration and may be different from the first parameter configuration 1010A and the second parameter configuration 1030A. In one example, the common parameter configuration 1020A may be a fixed parameter configuration. Furthermore, the common parameter configuration 1020A may be independent of the first parameter configuration 1010A and the second parameter configuration 1030A.

[0134] like Fig. 10B As shown in the example in and similar to Fig. 10AIn the example shown, a first parameter configuration 1010B may be used by a first WTRU group within a first portion of a channel bandwidth, and a second parameter configuration 1030B may be used by a second WTRU group within a second portion of a channel bandwidth. In one example, the first parameter configuration 1010B may be used by a URLLC WTRU, and the second parameter configuration 1030B may be used by an mMTC WTRU. A common parameter configuration 1020B may be used by an SSS 1050B and a PSS 1060B. In one example, the common parameter configuration 1020B may be used across a channel bandwidth and in a time resource between the time resources used for the first parameter configuration 1010B and the second parameter configuration 1030B. In one example, the common parameter configuration 1020B may be the same parameter configuration as one of the first parameter configuration 1010B and the second parameter configuration 1030B. In another example, the common parameter 1020B may be a third parameter configuration and may be different from the first parameter configuration 1010B and the second parameter configuration 1030B. In one example, the public parameter configuration 1020B may be a fixed parameter configuration. Further, the public parameter configuration 1020B may be independent of the first parameter configuration 1010B and the second parameter configuration 1030B.

[0135] For some scenarios (such as wide bandwidth scenarios), there may be multiple public configuration parameter areas, for example, to carry one or more system signals. The public configuration parameters can be used in the public configuration parameter area. Examples of system signals may include synchronization signals, broadcast signal lights, etc. The location of the public parameter configuration area may depend on the system bandwidth (e.g., 200 megahertz (MHz), up to 1 gigahertz (GHz) or 2GHz) and / or frequency band (e.g., 28GHz frequency band). In an example, the public parameter configuration area may be equally spaced within the system bandwidth. The number of the intervals and / or public parameter configuration areas may depend on the system bandwidth and / or frequency band.

[0136] When the WTRU searches for a cell, the WTRU may search according to a frequency raster (eg, 200 kHz for LTE). The frequency raster may depend on the frequency band. The location of the common parameter configuration area may depend on the frequency raster.

[0137] Examples of WTRUs that may or may not use multiple parameter configurations may include low-cost IoT devices. If some WTRUs within the network do not use multiple parameter configurations, the base station may transmit a parameter configuration specific synchronization signal that may be in accordance with Fig. 10A and 10B The specific locations of those SSs may be signaled from higher layers in a static or dynamic manner so that the WTRUs know where to find the SSs.

[0138] In an example, uplink control channel mapping for a hybrid parameter configuration system may be used. Since PUCCH resources may be mapped to the edge of the component carrier bandwidth, the use of hybrid parameter configuration may adversely affect PUCCH transmissions. The format of the PUCCH transmission (such as, for example, PUCCH format 1 and PUCCH format 2) may be utilized to determine the robustness given to the transmission.

[0139] For example, PUCCH format 2 (for channel status reporting) may be transmitted closest to the edge of the uplink bandwidth, while PUCCH format 1 (for HARQ reporting and scheduling requests) may be mapped thereafter. Since PUCCH format 2 is mapped to resources closest to the band edge, these transmissions may be more sensitive to interference from neighboring parameter configurations.

[0140] When the WTRU has multiple transmit antennas, one way to improve PUCCH performance may be to exploit multi-antenna transmit diversity. In this case, the WTRU may transmit PUCCH by using multiple frequency resources from different antennas. Thus, the WTRU may improve PUCCH performance, although this is at the expense of using an increased number of resources. In this example, the additional resources used are not limited to the frequency domain, but may also be extended to include additional resources in the time domain.

[0141] Another example of achieving higher robustness may be to reduce the coding rate of control information transmitted in the partition edge region. In one example, the control information may be spread over more subcarriers when transmitted at the band edge or partition edge. In another example, the control information may be repeated when transmitted at the band edge or partition edge.

[0142] Another example may include transmitting control information on resources that are not mapped to the band edge or partition edge. For example, if OFDM is used for uplink transmission, the WTRU may transmit its control information within its resources allocated by the central controller. If the WTRU is not allocated any resources, the control information may be transmitted on a set of reserved resources. If a single carrier waveform (such as DFT-s-OFDM) is used for uplink transmission, a set of resources away from the band edge may be reserved for control channel transmission. An example that may be used to indicate the allocated set of resources may include signaling the allocation to the WTRU.

[0143] Fig.11 1100 is a schematic diagram showing an example of control channel allocation. In the example shown in schematic diagram 1100, the number of subcarriers or the number of subcarrier groups that can be excluded from control information transmission can be signaled. In an example, the size of the subcarrier group can be predetermined or defined.

[0144] like Fig.11As shown, the first partition 1110 can be used for the first parameter configuration, and the second partition 1160 can be used for the second parameter configuration. In the control region, resources 1120 in the first partition 1110 can be used for the first control channel, and resources 1170 in the second partition 1160 can be used for the second control channel. Codeword A 1130 and codeword B 1140 can be transmitted in the data region in the first partition 1110, and codeword C 1180 and codeword D 1190 can be transmitted in the data region in the second partition 1160. Resource 1150 may not be used for the control channel.

[0145] In one example, k1 subcarriers within the first partition 1110 and k2 subcarriers within the second partition 1160 may be excluded from being used for control channels. In other words, k1 subcarriers and k2 subcarriers within the resource 1150 may be excluded from being used for control channels. It will be appreciated by those skilled in the art that in this example, the left and right sides of the partition may not have edges close to other partitions, respectively. Therefore, the subcarriers on these sides may not need to be excluded from being used for control channels. However, in general, subcarriers on both sides of the partition should be excluded.

[0146] The number of subcarriers k1 and k2 may be signaled by the central controller in the established time partition or semi-statically configured. In one example, only k1, k2 or another value may be signaled or configured, and the corresponding other values ​​may be calculated from the signaled values. For example, 180 MHz of spectrum may be excluded from control channel transmission. The WTRU may calculate that 180 MHz corresponds to 12 subcarriers in a partition with a subcarrier spacing of 15 KHz and 36 subcarriers in a partition with a subcarrier spacing of 5 KHz. The excluded subcarriers may be used for the transmission of user data or other less important signals. For example, k1 subcarriers in resource 1120 and k2 subcarriers in resource 1150 may be used for the transmission of user data or other less important signals.

[0147] In an example, a method for alleviating uneven SINR distribution in the time domain across subframes / TTIs may be used. In some scenarios, the SINR may be unevenly distributed within the time domain across subframes or TTIs. These scenarios may include, but are not limited to, operation within a frequency selective channel when there is a transition from DTX (no transmission) to transmitting data or when frequency hopping is used. In these cases, the first (or first few) symbols of the transmission after the interruption may be affected by interference, and the SINR may be lower at the beginning of the subframe / TTI than the rest of the subframe / TTI.

[0148] Fig.12Schematic diagram showing an exemplary method for uneven time domain SINR distribution. In the example shown in schematic diagram 1200, the conversion and / or interruption within TTI1 and TTI3 may cause the SINR in the area 1250 at the beginning of the TTI / subframe to decrease or the SINR to decrease. In an example, the first (or first few) OFDM, DFT-s-OFDM, or unique word (UW) / zero tail (ZT) DFT-s-OFDM symbol 1210 of the subframe / TTI may be configured to use a lower modulation order. This can alleviate the SINR loss of the first OFDM symbol 1210. The remaining OFDM / DFT-s-OFDM symbols 1260 of the subframe / TTI may be configured for a higher modulation order.

[0149] Fig.13 13 is a schematic diagram showing an exemplary method for non-uniform time domain SINR distribution per RB. In the example shown in the schematic diagram 1300, the first (one or several) OFDM symbols 1310 of the subframe may use low-order modulation, such as binary phase shift keying (BPSK) or QPSK, while the remaining symbols 1360 may use 16-QAM, 64-QAM or higher-order modulation. Fig.13 The example shown is for one resource block (RB).

[0150] Fig.14 14 is a schematic diagram showing an exemplary method for uneven time and frequency domain SINR distribution with multiple RBs. In the example shown in schematic diagram 1400, when RBs are allocated closer to the partition edge, REs 1410 in the interrupted RBs that may be closer to the partition edge in the time and frequency domains may be allocated a lower modulation order. Fig.14 As shown, partition edge 1430 may be in the frequency domain, while partition edge 1440 may be in the time domain. In an example, partition edge may be a band edge in the frequency domain. For example, partition edge 1430 may be a band edge. Remaining REs 1460 may be assigned a higher modulation order.

[0151] Although the features and elements are described above in specific combinations, it will be recognized by those skilled in the art that each feature or element can be used alone or in any combination with other features and elements. In addition, the methods described herein can be implemented in a computer program, software, or firmware that is introduced into a computer-readable medium for operation by a computer or processor. Examples of computer-readable media include electrical signals (transmitted via a wired or wireless connection) and computer-readable storage media. Examples of computer-readable storage media include, but are not limited to, read-only memory (ROM), random access memory (RAM), registers, buffer memory, semiconductor storage devices, magnetic media such as internal hard disks and removable disks, magneto-optical media, and optical media such as CD-ROM disks and digital versatile disks (DVDs). A processor associated with the software can be used to implement a radio frequency transceiver used in a WTRU, UE, terminal, base station, RNC, or any computer host.

Claims

1. A wireless transmit / receive unit (WTRU), the WTRU comprising: transceiver; as well as a processor operably coupled to the transceiver; wherein: The transceiver is configured to receive a first signal including a primary synchronization signal (PSS) and a secondary synchronization signal (SSS) in a cell, wherein the PSS and the SSS use a first parameter configuration, wherein the first parameter configuration has a first subcarrier spacing, and wherein other resources of the cell concurrently with the PSS or the SSS use a second parameter configuration having a subcarrier spacing different from the first parameter configuration.

2. The WTRU of claim 1 , wherein the processor and the transceiver are further configured to synchronize timing of the cell based on the PSS and SSS.

3. The WTRU of claim 2, wherein the transceiver is further configured to receive a second signal in the cell.

4. The WTRU of claim 3, wherein the second signal is configured using the second parameter.

5. The WTRU of claim 4, wherein the processor and the transceiver are further configured to transmit user data.

6. The WTRU of claim 1, wherein the transceiver and the processor are further configured to search a frequency grid for the PSS and the SSS.

7. The WTRU of claim 6, wherein the frequency grid varies based on a frequency band being searched.

8. The WTRU of claim 7, wherein the first parameter configuration is based on the frequency band being searched.

9. The WTRU of claim 1, wherein the first signal comprises a reference signal and a broadcast signal for a plurality of WTRUs.

10. The WTRU of claim 1, wherein the second signal is received using one or more of the other resources and is received in a portion of a cell bandwidth configured with the second parameters.

11. The WTRU of claim 1 , wherein the second signal is a control channel signal.

12. The WTRU of claim 1, wherein the PSS and the SSS are received in a set of resource elements (REs).

13. The WTRU of claim 12, wherein the PSS is received in a first symbol in the set of REs.

14. The WTRU of claim 12, wherein the SSS is received in a second symbol in the set of REs.

15. The WTRU of claim 13, wherein the first symbol is a first orthogonal frequency division multiplexing (OFDM) symbol.

16. The WTRU of claim 14, wherein the second symbol is a second OFDM symbol.

17. A method for use in a wireless transmit / receive unit (WTRU), the method comprising: A first signal including a primary synchronization signal (PSS) and a secondary synchronization signal (SSS) is received in a cell, wherein the PSS and the SSS use a first parameter configuration, wherein the first parameter configuration has a first subcarrier spacing, and wherein other resources of the cell concurrently with the PSS or the SSS use a second parameter configuration having a subcarrier spacing different from the first parameter configuration.

18. The method according to claim 17, further comprising: The timing of the cell is synchronized based on the PSS and SSS.

19. The method according to claim 18, further comprising: A second signal is received in the cell, wherein the second signal is configured using the second parameter.

20. The method according to claim 19, further comprising: Transmit user data.

21. A method for use in a wireless transmit / receive unit (WTRU), the method comprising: Receive assignment information for receiving a first codeword using a first modulation and coding scheme (MCS) in a first resource block (RB) set and for receiving a second codeword using a different second MCS in a second RB set, wherein the first RB set and the second RB set are in a first time interval within a first bandwidth portion using a first subcarrier spacing.

22. The method according to claim 21, further comprising: In one or more symbols of the first time interval within the first bandwidth portion using the first subcarrier spacing, the first codeword is received in the first RB set using the first MCS and the second codeword is received in the second RB set using the second different MCS.

23. The method of claim 22, wherein at least a portion of the first codeword and at least a portion of the second codeword are received in at least a first symbol of the one or more symbols within the first time interval.

24. The method of claim 21, wherein the first MCS has a lower order modulation than the second MCS.

25. The method of claim 21, further comprising: A third codeword is received in a third set of RBs in a second time interval within a second bandwidth portion using a second subcarrier spacing.

26. The method according to claim 25, further comprising: A fourth codeword is received in a fourth set of RBs in a second time interval within a second bandwidth portion using a second subcarrier spacing.

27. The method of claim 21, wherein the assignment information is received in downlink control information (DCI).

28. The method of claim 21, wherein the assignment information comprises an overlap of the first set of RBs and the second set of RBs in a time domain.

29. The method of claim 21, wherein the first MCS has quadrature phase shift keying (QPSK) modulation, 16-quadrature amplitude modulation (QAM), or 64-QAM.

30. The method of claim 21, wherein the second MCS has QPSK modulation, 16-QAM, or 64-QAM.

31. The method of claim 21, wherein at least a portion of the first codeword and at least a portion of the second codeword are received in a second symbol of the one or more symbols in the first time interval.

32. A wireless transmit / receive unit (WTRU), the WTRU comprising: transceiver; as well as a processor operably coupled to the transceiver; wherein: The transceiver and the processor are configured to receive assignment information for receiving a first codeword using a first modulation and coding scheme (MCS) in a first resource block (RB) set, and for receiving a second codeword using a different second MCS in a second RB set, wherein the first RB set and the second RB set are in a first time interval within a first bandwidth portion using a first subcarrier spacing.

33. A WTRU according to claim 32, wherein the transceiver and the processor are also configured to receive the first codeword using the first MCS in the first RB set and receive the second codeword using the different second MCS in the second RB set in one or more symbols of the first time interval within the first bandwidth portion using the first subcarrier spacing.

34. The WTRU of claim 33, wherein at least a portion of the first codeword and at least a portion of the second codeword are received in at least a first symbol of the one or more symbols within the first time interval.

35. The WTRU of claim 32, wherein the first MCS has a lower order modulation than the second MCS.

36. The WTRU of claim 32 further comprising: A third codeword is received in a third set of RBs in a second time interval within a second bandwidth portion using a second subcarrier spacing.

37. The WTRU of claim 36 further comprising: A fourth codeword is received in a fourth set of RBs in a second time interval within a second bandwidth portion using a second subcarrier spacing.

38. The WTRU of claim 32, wherein the assignment information is received in downlink control information (DCI).

39. The WTRU of claim 32, wherein the assignment information includes an overlap of the first set of RBs and the second set of RBs in the time domain.

40. The WTRU of claim 32, wherein the first MCS has quadrature phase shift keying (QPSK) modulation, 16-quadrature amplitude modulation (QAM), or 64-QAM.

41. The WTRU of claim 32, wherein the second MCS has QPSK modulation, 16-QAM, or 64-QAM.

42. The WTRU of claim 32, wherein at least a portion of the first codeword and at least a portion of the second codeword are received in a second symbol of the one or more symbols in the first time interval.

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