Patent Description:
The present application relates to wireless devices, and more particularly to apparatus, systems, and methods for providing downlink control for non coherent joint transmission.

Wireless communication systems are rapidly growing in usage. In recent years, wireless devices such as smart phones and tablet computers have become increasingly sophisticated. In addition to supporting telephone calls, many mobile devices now provide access to the internet, email, text messaging, and navigation using the global positioning system (GPS), and are capable of operating sophisticated applications that utilize these functionalities. Additionally, there exist numerous different wireless communication technologies and standards. Some examples of wireless communication standards include GSM, UMTS (associated with, for example, WCDMA or TD-SCDMA air interfaces), LTE, LTE Advanced (LTE-A), HSPA, 3GPP2 CDMA2000 (e.g., 1xRTT, 1xEV-DO, HRPD, eHRPD), IEEE <NUM> (WLAN or Wi-Fi), BLUETOOTH™, etc..

The ever increasing number of features and functionality introduced in wireless communication devices also creates a continuous need for improvement in both wireless communications and in wireless communication devices. To increase coverage and better serve the increasing demand and range of envisioned uses of wireless communication, in addition to the communication standards mentioned above, there are further wireless communication technologies under development, including fifth generation (<NUM>) new radio (NR) communication. Accordingly, improvements in the field in support of such development and design are desired. <CIT> relates to an information acquisition method. A user equipment receives quantity information, transmitted by a transmitting and receiving point (TRP), about control information to be transmitted to the user equipment, wherein the quantity of the control information to be transmitted to the user equipment is N, with N being an integer greater than or equal to <NUM>; the user equipment determines, according to the quantity information, that the quantity of control information needing to be detected is N; and the user equipment detects the N pieces of control information. <NPL>, relates to UL and DL multi-TRP and multi-panel in NR. <NPL>, relates to DL beam indication for PDSCH and PDCCH, UL beam indication, and beam measurement and reporting.

Embodiments relate to apparatuses, systems, and methods to provide downlink control for non coherent joint transmission.

The techniques described herein include various approaches to providing downlink control information for non coherent joint transmission data communications, including multiple possible downlink control information formats for each of non coherent joint transmission downlink data communications and non coherent joint transmission uplink data communications.

The various formats for each of downlink and uplink non coherent joint transmission data communications may include a single downlink control information transmission, a multi-stage downlink control information transmission, and/or multiple downlink control information transmissions. Providing multiple such formats may allow for substantial flexibility when scheduling and configuring non coherent joint transmission communications.

Techniques are also described herein for facilitating determining whether non coherent joint transmission is supported by a wireless device, and for determining when to activate or deactivate non coherent joint transmission, e.g., based on conditions being experienced by the wireless device, among various other techniques described herein.

The techniques described herein may be implemented in and/or used with a number of different types of devices, including but not limited to cellular phones, tablet computers, wearable computing devices, portable media players, and any of various other computing devices.

While the features described herein may be susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the drawings and detailed description thereto are not intended to be limiting to the particular form disclosed, but on the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the scope of the subject matter as defined by the appended claims.

The following is a glossary of terms used in this disclosure:
Memory Medium - Any of various types of non-transitory memory devices or storage devices. The term "memory medium" is intended to include an installation medium, e.g., a CD-ROM, floppy disks, or tape device; a computer system memory or random access memory such as DRAM, DDR RAM, SRAM, EDO RAM, Rambus RAM, etc.; a non-volatile memory such as a Flash, magnetic media, e.g., a hard drive, or optical storage; registers, or other similar types of memory elements, etc. The memory medium may include other types of non-transitory memory as well or combinations thereof. In addition, the memory medium may be located in a first computer system in which the programs are executed, or may be located in a second different computer system which connects to the first computer system over a network, such as the Internet. In the latter instance, the second computer system may provide program instructions to the first computer for execution. The term "memory medium" may include two or more memory mediums which may reside in different locations, e.g., in different computer systems that are connected over a network. The memory medium may store program instructions (e.g., embodied as computer programs) that may be executed by one or more processors.

Computer System - any of various types of computing or processing systems, including a personal computer system (PC), mainframe computer system, workstation, network appliance, Internet appliance, personal digital assistant (PDA), television system, grid computing system, or other device or combinations of devices. In general, the term "computer system" can be broadly defined to encompass any device (or combination of devices) having at least one processor that executes instructions from a memory medium.

User Equipment (UE) (or "UE Device") - any of various types of computer systems or devices that are mobile or portable and that perform wireless communications. Examples of UE devices include mobile telephones or smart phones (e.g., iPhone™, Android™-based phones), portable gaming devices (e.g., Nintendo DS™, PlayStation Portable™, Gameboy Advance™, iPhone™), laptops, wearable devices (e.g. smart watch, smart glasses), PDAs, portable Internet devices, music players, data storage devices, or other handheld devices, etc. In general, the term "UE" or "UE device" can be broadly defined to encompass any electronic, computing, and/or telecommunications device (or combination of devices) which is easily transported by a user and capable of wireless communication.

Processing Element (or Processor) - refers to various elements or combinations of elements that are capable of performing a function in a device, such as a user equipment or a cellular network device. Processing elements may include, for example: processors and associated memory, portions or circuits of individual processor cores, entire processor cores, individual processors, processor arrays, circuits such as an ASIC (Application Specific Integrated Circuit), programmable hardware elements such as a field programmable gate array (FPGA), as well any of various combinations of the above.

The base station (BS) 102A may be a base transceiver station (BTS) or cell site (a "cellular base station"), and may include hardware that enables wireless communication with the UEs 106A through 106N.

The communication area (or coverage area) of the base station may be referred to as a "cell. " The base station 102A and the UEs <NUM> may be configured to communicate over the transmission medium using any of various radio access technologies (RATs), also referred to as wireless communication technologies, or telecommunication standards, such as GSM, UMTS (associated with, for example, WCDMA or TD-SCDMA air interfaces), LTE, LTE-Advanced (LTE-A), <NUM> new radio (<NUM> NR), HSPA, 3GPP2 CDMA2000 (e.g., 1xRTT, 1xEV-DO, HRPD, eHRPD), etc. Note that if the base station 102A is implemented in the context of LTE, it may alternately be referred to as an 'eNodeB' or 'eNB'. Note that if the base station 102A is implemented in the context of <NUM> NR, it may alternately be referred to as a 'gNodeB' or 'gNB'.

In some embodiments, base station 102A may be a next generation base station, e.g., a <NUM> New Radio (<NUM> NR) base station, or "gNB". In some embodiments, a gNB may be connected to a legacy evolved packet core (EPC) network and/or to a NR core (NRC) network. In addition, a gNB cell may include one or more transition and reception points (TRPs). For example, it may be possible that that the base station 102A and one or more other base stations <NUM> support joint transmission, such that UE <NUM> may be able to receive transmissions from multiple base stations (and/or multiple TRPs provided by the same base station).

Note that a UE <NUM> may be capable of communicating using multiple wireless communication standards. For example, the UE <NUM> may be configured to communicate using a wireless networking (e.g., Wi-Fi) and/or peer-to-peer wireless communication protocol (e.g., Bluetooth, Wi-Fi peer-to-peer, etc.) in addition to at least one cellular communication protocol (e.g., GSM, UMTS (associated with, for example, WCDMA or TD-SCDMA air interfaces), LTE, LTE-A, <NUM> NR, HSPA, 3GPP2 CDMA2000 (e.g., 1xRTT, 1xEV-DO, HRPD, eHRPD), etc.). The UE <NUM> may also or alternatively be configured to communicate using one or more global navigational satellite systems (GNSS, e.g., GPS or GLONASS), one or more mobile television broadcasting standards (e.g., ATSC-M/H), and/or any other wireless communication protocol, if desired. Other combinations of wireless communication standards (including more than two wireless communication standards) are also possible.

<FIG> illustrates user equipment <NUM> (e.g., one of the devices 106A through 106N) in communication with a base station <NUM>, according to some embodiments. The UE <NUM> may be a device with cellular communication capability such as a mobile phone, a hand-held device, a computer, a laptop, a tablet, a smart watch or other wearable device, or virtually any type of wireless device.

The UE <NUM> may include a processor (processing element) that is configured to execute program instructions stored in memory. Alternatively, or in addition, the UE <NUM> may include a programmable hardware element such as an FPGA (field-programmable gate array), an integrated circuit, and/or any of various other possible hardware components that are configured to perform (e.g., individually or in combination) any of the method embodiments described herein, or any portion of any of the method embodiments described herein.

The UE <NUM> may include one or more antennas for communicating using one or more wireless communication protocols or technologies. In some embodiments, the UE <NUM> may be configured to communicate using, for example, NR or LTE using at least some shared radio components. As additional possibilities, the UE <NUM> could be configured to communicate using CDMA2000 (<NUM>×RTT / 1xEV-DO / HRPD / eHRPD) or LTE using a single shared radio and/or GSM or LTE using the single shared radio. The shared radio may couple to a single antenna, or may couple to multiple antennas (e.g., for MIMO) for performing wireless communications. In general, a radio may include any combination of a baseband processor, analog RF signal processing circuitry (e.g., including filters, mixers, oscillators, amplifiers, etc.), or digital processing circuitry (e.g., for digital modulation as well as other digital processing). Similarly, the radio may implement one or more receive and transmit chains using the aforementioned hardware. For example, the UE <NUM> may share one or more parts of a receive and/or transmit chain between multiple wireless communication technologies, such as those discussed above.

For example, the UE <NUM> might include a shared radio for communicating using either of LTE or <NUM> NR (or either of LTE or <NUM>×RTT, or either of LTE or GSM, among various possibilities), and separate radios for communicating using each of Wi-Fi and Bluetooth.

<FIG> illustrates an example simplified block diagram of a communication device <NUM>, according to some embodiments. It is noted that the block diagram of the communication device of <FIG> is only one example of a possible communication device. According to embodiments, communication device <NUM> may be a user equipment (UE) device, a mobile device or mobile station, a wireless device or wireless station, a desktop computer or computing device, a mobile computing device (e.g., a laptop, notebook, or portable computing device), a tablet, and/or a combination of devices, among other devices. As shown, the communication device <NUM> may include a set of components <NUM> configured to perform core functions. For example, this set of components may be implemented as a system on chip (SOC), which may include portions for various purposes. Alternatively, this set of components <NUM> may be implemented as separate components or groups of components for the various purposes. The set of components <NUM> may be coupled (e.g., communicatively; directly or indirectly) to various other circuits of the communication device <NUM>.

For example, the communication device <NUM> may include various types of memory (e.g., including NAND flash <NUM>), an input/output interface such as connector I/F <NUM> (e.g., for connecting to a computer system; dock; charging station; input devices, such as a microphone, camera, keyboard; output devices, such as speakers; etc.), the display <NUM>, which may be integrated with or external to the communication device <NUM>, and wireless communication circuitry <NUM> (e.g., for LTE, LTE-A, NR, UMTS, GSM, CDMA2000, Bluetooth, Wi-Fi, NFC, GPS, etc.).

The wireless communication circuitry <NUM> may couple (e.g., communicatively; directly or indirectly) to one or more antennas, such as antenna(s) <NUM> as shown. The wireless communication circuitry <NUM> may include cellular communication circuitry and/or short to medium range wireless communication circuitry, and may include multiple receive chains and/or multiple transmit chains for receiving and/or transmitting multiple spatial streams, such as in a multiple-input multiple output (MIMO) configuration.

In some embodiments, as further described below, cellular communication circuitry <NUM> may include one or more receive chains (including and/or coupled to (e.g., communicatively; directly or indirectly) dedicated processors and/or radios) for multiple RATs (e.g., a first receive chain for LTE and a second receive chain for <NUM> NR). For example, a first radio may be dedicated to a first RAT, e.g., LTE, and may be in communication with a dedicated receive chain and a transmit chain shared with a second radio. The second radio may be dedicated to a second RAT, e.g., <NUM> NR, and may be in communication with a dedicated receive chain and the shared transmit chain.

As shown, the SOC <NUM> may include processor(s) <NUM>, which may execute program instructions for the communication device <NUM> and display circuitry <NUM>, which may perform graphics processing and provide display signals to the display <NUM>. The processor(s) <NUM> may also be coupled to memory management unit (MMU) <NUM>, which may be configured to receive addresses from the processor(s) <NUM> and translate those addresses to locations in memory (e.g., memory <NUM>, read only memory (ROM) <NUM>, NAND flash memory <NUM>) and/or to other circuits or devices, such as the display circuitry <NUM>, wireless communication circuitry <NUM>, connector I/F <NUM>, and/or display <NUM>. The MMU <NUM> may be configured to perform memory protection and page table translation or set up. In some embodiments, the MMU <NUM> may be included as a portion of the processor(s) <NUM>.

As noted above, the communication device <NUM> may be configured to communicate using wireless and/or wired communication circuitry. As described herein, the communication device <NUM> may include hardware and software components for implementing any of the various features and techniques described herein. The processor <NUM> of the communication device <NUM> may be configured to implement part or all of the features described herein, e.g., by executing program instructions stored on a memory medium (e.g., a non-transitory computer-readable memory medium). Alternatively (or in addition), processor <NUM> may be configured as a programmable hardware element, such as an FPGA (Field Programmable Gate Array), or as an ASIC (Application Specific Integrated Circuit). Alternatively (or in addition) the processor <NUM> of the communication device <NUM>, in conjunction with one or more of the other components <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> may be configured to implement part or all of the features described herein.

Further, as described herein, wireless communication circuitry <NUM> may include one or more processing elements. In other words, one or more processing elements may be included in wireless communication circuitry <NUM>. Thus, wireless communication circuitry <NUM> may include one or more integrated circuits (ICs) that are configured to perform the functions of wireless communication circuitry <NUM>. In addition, each integrated circuit may include circuitry (e.g., first circuitry, second circuitry, etc.) configured to perform the functions of wireless communication circuitry <NUM>.

As another possibility, the base station <NUM> may include a multi-mode radio which is capable of performing communications according to any of multiple wireless communication technologies (e.g., <NUM> NR and LTE, <NUM> NR and Wi-Fi, LTE and Wi-Fi, LTE and UMTS, LTE and CDMA2000, UMTS and GSM, etc.).

In addition, as described herein, processor(s) <NUM> may include one or more processing elements.

Further, as described herein, radio <NUM> may include one or more processing elements.

<FIG> illustrates an example simplified block diagram of cellular communication circuitry, according to some embodiments. It is noted that the block diagram of the cellular communication circuitry of <FIG> is only one example of a possible cellular communication circuit; other circuits, such as circuits including or coupled to sufficient antennas for different RATs to perform uplink activities using separate antennas, or circuits including or coupled to fewer antennas, e.g., that may be shared among multiple RATs, are also possible. According to some embodiments, cellular communication circuitry <NUM> may be included in a communication device, such as communication device <NUM> described above. As noted above, communication device <NUM> may be a user equipment (UE) device, a mobile device or mobile station, a wireless device or wireless station, a desktop computer or computing device, a mobile computing device (e.g., a laptop, notebook, or portable computing device), a tablet and/or a combination of devices, among other devices.

The cellular communication circuitry <NUM> may couple (e.g., communicatively; directly or indirectly) to one or more antennas, such as antennas 335a-b and <NUM> as shown. In some embodiments, cellular communication circuitry <NUM> may include dedicated receive chains (including and/or coupled to (e.g., communicatively; directly or indirectly) dedicated processors and/or radios) for multiple RATs (e.g., a first receive chain for LTE and a second receive chain for <NUM> NR). For example, as shown in <FIG>, cellular communication circuitry <NUM> may include a first modem <NUM> and a second modem <NUM>. The first modem <NUM> may be configured for communications according to a first RAT, e.g., such as LTE or LTE-A, and the second modem <NUM> may be configured for communications according to a second RAT, e.g., such as <NUM> NR.

As shown, the first modem <NUM> may include one or more processors <NUM> and a memory <NUM> in communication with processors <NUM>.

Similarly, the second modem <NUM> may include one or more processors <NUM> and a memory <NUM> in communication with processors <NUM>.

Thus, when cellular communication circuitry <NUM> receives instructions to transmit according to the first RAT (e.g., as supported via the first modem <NUM>), switch <NUM> may be switched to a first state that allows the first modem <NUM> to transmit signals according to the first RAT (e.g., via a transmit chain that includes transmit circuitry <NUM> and UL front end <NUM>). Similarly, when cellular communication circuitry <NUM> receives instructions to transmit according to the second RAT (e.g., as supported via the second modem <NUM>), switch <NUM> may be switched to a second state that allows the second modem <NUM> to transmit signals according to the second RAT (e.g., via a transmit chain that includes transmit circuitry <NUM> and UL front end <NUM>).

As described herein, the first modem <NUM> and/or the second modem <NUM> may include hardware and software components for implementing any of the various features and techniques described herein. The processors <NUM>, <NUM> may be configured to implement part or all of the features described herein, e.g., by executing program instructions stored on a memory medium (e.g., a non-transitory computer-readable memory medium). Alternatively (or in addition), processors <NUM>, <NUM> may be configured as a programmable hardware element, such as an FPGA (Field Programmable Gate Array), or as an ASIC (Application Specific Integrated Circuit). Alternatively (or in addition) the processors <NUM>, <NUM>, in conjunction with one or more of the other components <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> and <NUM> may be configured to implement part or all of the features described herein.

In addition, as described herein, processors <NUM>, <NUM> may include one or more processing elements. Thus, processors <NUM>, <NUM> may include one or more integrated circuits (ICs) that are configured to perform the functions of processors <NUM>, <NUM>. In addition, each integrated circuit may include circuitry (e.g., first circuitry, second circuitry, etc.) configured to perform the functions of processors <NUM>, <NUM>.

In some embodiments, the cellular communication circuitry <NUM> may include only one transmit/receive chain. For example, the cellular communication circuitry <NUM> may not include the modem <NUM>, the RF front end <NUM>, the DL front end <NUM>, and/or the antenna 335b. As another example, the cellular communication circuitry <NUM> may not include the modem <NUM>, the RF front end <NUM>, the DL front end <NUM>, and/or the antenna 335a. In some embodiments, the cellular communication circuitry <NUM> may also not include the switch <NUM>, and the RF front end <NUM> or the RF front end <NUM> may be in communication, e.g., directly, with the UL front end <NUM>.

New cellular communication techniques are continually under development, to increase coverage, to better serve the range of demands and use cases, and for a variety of other reasons. One technique that is currently under development may include non coherent joint transmission, in which multiple TRPs can schedule independent data streams to a wireless device without joint precoding. As part of such development, it would be useful to provide a downlink control framework that can support such a technique.

Accordingly, <FIG> is a signal flow diagram illustrating an example of such a method, at least according to some embodiments. Aspects of the method of <FIG> may be implemented by a wireless device such as a UE <NUM> illustrated in various of the Figures herein, a base station such as a BS <NUM> illustrated in various of the Figures herein, and/or more generally in conjunction with any of the computer circuitry, systems, devices, elements, or components shown in the above Figures, among others, as desired. For example, a processor (and/or other hardware) of such a device may be configured to cause the device to perform any combination of the illustrated method elements and/or other method elements.

In various embodiments, some of the elements of the methods shown may be performed concurrently, in a different order than shown, may be substituted for by other method elements, or may be omitted. Additional elements may also be performed as desired. As shown, the method of <FIG> may operate as follows.

At <NUM>, a wireless device may receive downlink control information for non coherent joint transmission. The downlink control information may be provided in any of a variety of possible formats. At least according to some embodiments, the wireless device may receive an indication of which of multiple possible formats is being used to provide the downlink control information. For example, such information may be broadcast by a base station to which the wireless device is attached in a system information broadcast, among various other possibilities.

As one possible format, the downlink control information may be provided as a single downlink control information transmission that includes scheduling information for multiple downlink data streams of the non coherent joint transmission data communication. In such a case, the downlink control information may include separate / independent scheduling information for each downlink data stream, or may include scheduling information that is common to the two downlink data streams and scheduling information that is specific to each of the two downlink data streams, e.g., to more efficiently communicate the scheduling information.

As another possible format, the downlink control information may be provided as a multi-stage downlink control information transmission. In such a case, the wireless device may receive a first portion of the multi-stage downlink control information transmission as well as a second portion of the multi-stage downlink control information transmission. The first portion may include scheduling information for a first downlink data stream of the non coherent joint transmission data communication, while the second portion may include scheduling information for a second downlink data stream of the non coherent joint transmission data communication. According to some embodiments, the first portion may include information indicating the existence of the second portion, and/or may include downlink control information configuration information for the second portion. In some instances, the second portion may omit scheduling information for the second downlink data stream that is in common with the first downlink data stream, e.g., to more efficiently signal the downlink control information. If desired, the time and frequency resources on which the second portion are provided may be predetermined relative to time and frequency resources on which the first portion are provided, e.g., to simplify the decoding process for the wireless device.

As a still further possibility, multiple downlink control information transmissions may be provided to the wireless device in conjunction with the non coherent joint transmission data communication. For example, the downlink control information received by the wireless device may include first downlink control information for a first downlink data stream of the non coherent joint transmission data communication and separate second downlink control information for a second downlink data stream of the non coherent joint transmission data communication. The first downlink control information may include information indicating the existence of the second downlink control information, and the second downlink control information may include information indicating the existence of the first downlink control information. Further, the first downlink control information may include configuration information for the second downlink control information, and the second downlink control information may include configuration information for the first downlink control information, at least according to some embodiments. It may be the case that time and frequency resources on which the second downlink control information is provided are predetermined relative to time and frequency resources on which the first downlink control information is provided, e.g., to simplify the decoding process for the wireless device. In some instances, the second downlink control information may omit scheduling information for the second downlink data stream of the non coherent joint transmission data communication that is in common with the first downlink data stream of the non coherent joint transmission data communication.

As one possible benefit (at least according to some embodiments) of supporting a downlink control information format for non coherent joint transmission in which multiple downlink control information transmissions are provided, such a format may possibly enable support of non coherent joint transmission with TRPs that have a relatively low level of scheduling coordination. In such a case, it may further be beneficial to provide a mechanism for semi-statically partitioning reference signal ports between TRPs associated with a non coherent joint transmission. For example, in a scenario in which a first downlink data stream is associated with a first TRP and a second downlink data stream is associated with a second TRP, reference signal ports may be semi-statically partitioned between the first TRP and the second TRP, and an indication of the partitioning of the reference signal ports between the first TRP and the second TRP may be provided to the wireless device.

It is possible for the downlink control information to be associated with a non coherent joint transmission uplink data communication, according to some embodiments. Similar to downlink control information associated with a non coherent joint transmission downlink data communication, there may be multiple possible formats that can be used for such downlink control information, at least according to some embodiments.

For example, as one possibility, the downlink control information may include a single downlink control information transmission scheduling a single non coherent joint transmission uplink data communication to multiple distributed reception points.

As another possibility, the downlink control information may be a multi-stage downlink control information transmission, e.g., including a first portion that schedules a first uplink data stream to a first TRP and a second portion that schedules a second uplink data stream to a second TRP. In such a scenario, the second portion may include incremental configuration information for the second uplink data stream relative to the first uplink data stream, such that configuration information for the second uplink data stream that is in common with the first uplink data stream may be omitted from the second portion.

As a still further possibility, multiple downlink control information transmissions may be provided for the non coherent joint transmission uplink data communication, e.g., such that the wireless device may receive first downlink control information for a first uplink data stream of the non coherent joint transmission uplink data communication, and may separately receive second downlink control information for a second uplink data stream of the non coherent joint transmission uplink data communication transmission.

In some instances, the downlink control information for the non coherent joint transmission uplink data communication may include beam configuration information for the non coherent joint transmission uplink data communication. For example, the downlink control information may include downlink reference signal index information indicating a downlink beam for a downlink reference signal, which may be considered an indication of a beam configuration to use for at least a portion of the non coherent joint transmission uplink data communication (e.g., for an uplink data stream that is transmitted to a TRP that provides the downlink reference signal via the downlink beam). Thus, the wireless device may use the downlink beam for the downlink reference signal as an uplink beam to transmit at least a portion of the non coherent joint transmission uplink data communication based at least in part on the downlink reference signal index information. In some instances, similar configuration information may be received for each of multiple uplink beams to be used for multiple uplink data streams of the non coherent joint transmission uplink data communication.

In some instances, the downlink control information may potentially support a flexible MIMO layer to codeword mapping scheme. For example, the downlink control information could include any or all of MIMO layer, MIMO codeword, and/or MIMO layer-to-codeword mapping information for the non coherent joint transmission data streams.

According to some embodiments, the downlink control information may include transmission reception point (TRP) index information for the non coherent joint transmission downlink data communication. The TRP index information may indicate which downlink data of the non coherent joint transmission downlink data communication is transmitted by which TRP.

At least according to some embodiments, the wireless device may exchange signaling with the cellular network to determine whether non coherent joint transmission data communication is supported by both the wireless device and the cellular network, and/or to determine whether to activate non coherent joint transmission data communication, e.g., as a precursor to provision of the downlink control information for the non coherent joint transmission data communication. In such a case, the wireless device may provide capability information, such as information indicating whether the wireless device supports simultaneous multiple beam transmission, whether the wireless device can transmit non coherent joint transmission beams associated with different antenna panels of the wireless device or the same antenna panel of the wireless device, whether the wireless device supports non coherent joint transmission uplink communication, and/or whether the wireless device supports non coherent joint transmission downlink communication.

If non coherent joint transmission is supported, and support is further provided for indicating whether to activate or deactivate non coherent joint transmission, it may further be the case that the wireless device provides a request to activate non coherent joint transmission, e.g., if the wireless device determines non coherent joint transmission would be beneficial. In such a scenario, the cellular base station may provide an indication to activate non coherent joint transmission in response to the request, and the non coherent joint transmission communication may be performed based at least in part on the request to activate non coherent joint transmission and the indication to activate non coherent joint transmission. The wireless device may determine to request activation of non coherent joint transmission based on any of a variety of possible considerations, such as if the wireless device determines that a TRP strength difference between two TRPs is within a first threshold, if the wireless device determines that an uplink data buffer of the wireless device exceeds a buffer fullness threshold, and/or for any of various other possible reasons. Note additionally that it may be possible for a wireless device to support either, both, or neither of non coherent joint transmission uplink communication and downlink communication, and/or for each of non coherent joint transmission uplink communication and downlink communication to be activated/deactivated separately/independently or jointly, as desired.

Note that even when non coherent joint transmission is activated, it may be possible for a given data stream to be (e.g., temporarily) disabled. For example, a field of the downlink control information could be set to a reserved value to indicate that a downlink data stream associated with that portion of the downlink control information is disabled, as one possibility. Other techniques for signaling such possible disabling of a data stream of a non coherent joint transmission communication are also possible.

Similarly, the wireless device may be able to request deactivation of non coherent joint transmission, e.g., if the wireless device determines non coherent joint transmission would no longer be sufficiently beneficial. In such a scenario, the wireless device may provide a request to deactivate non coherent joint transmission, and may receive an indication to deactivate non coherent joint transmission in response to the request to deactivate non coherent joint transmission. The request to deactivate non coherent joint transmission may be based on a TRP strength difference between two TRPs exceeding a predetermined threshold, an uplink data buffer of the wireless device being below a buffer fullness threshold, and/or for any of various other possible reasons.

At <NUM>, the wireless device may perform the non coherent joint transmission data communication, e.g., based at least in part on the downlink control information associated with the non coherent joint transmission data communication. For example, performing the non coherent joint transmission data communication may include using scheduling information, configuration information, and/or other parameters/information provided in the downlink control information associated with the non coherent joint transmission data communication.

Thus, the wireless device may receive a non coherent joint transmission downlink data communication, e.g., if the downlink control information is associated with a non coherent joint transmission downlink data communication. Alternatively, the wireless device may transmit a non coherent joint transmission uplink data communication, e.g., if the downlink control information is associated with a non coherent joint transmission uplink data communication.

<FIG> illustrate further aspects that might be used in conjunction with the method of <FIG> if desired. It should be noted, however, that the exemplary details illustrated in and described with respect to <FIG> are not intended to be limiting to the disclosure as a whole: numerous variations and alternatives to the details provided herein below are possible and should be considered within the scope of the disclosure.

Non coherent joint transmission (NCJT) is a topic under consideration at least for 3GPP cellular communication, for example in conjunction with 3GPP release <NUM>. <FIG> illustrates an example NCJT scenario, e.g., in which two TRPs schedule two data streams without joint precoding to a wireless device. Design of a non coherent joint transmission framework may include a variety of considerations, e.g., potentially including downlink control (e.g., physical downlink control channel and DCI) design, uplink feedback (e.g., physical uplink control channel and ACK/NAK) design, channel state information reference signal (CSI-RS) configuration design, and channel state information (CSI) feedback design, among various possibilities.

Each such design area may itself include a variety of considerations. For example, for the downlink control framework, downlink DCI design and uplink DCI design may need to be considered, as well as at least some overall NCJT operation considerations.

For the downlink DCI design, there may be several possible approaches, including a single DCI design, a multi-stage DCI design, and/or a multiple DCI design.

<FIG> illustrates exemplary aspects of a possible single DCI approach. In such an approach, a UE may decode a single DCI transmission (e.g., from just one of the multiple TRPs) with scheduling information for both data streams. As shown, such an approach may include scheduling coordination support between the TRPs, e.g., such that the TRP providing the DCI is able to provide the scheduling information for both data streams in the DCI.

Such a single DCI transmission may be formatted in a variety of ways. As one possibility, a single DCI that includes independent scheduling information for each data stream, potentially including (but not limited to) frequency/time resource allocation, modulation and coding scheme (MCS), new data indicator (NDI), redundancy version (RV), hybrid automatic repeat request (HARQ) process number, antenna port, etc..

As another possibility, a single DCI that includes some information that is in common for the two data streams and some information that is different for the two data streams could be used. For example, the two data streams might have the same frequency/time resource allocation, but different MCS/NDI/RV, HARQ process number, antenna ports, etc. It may be possible for such a format to be more compact than a format in which scheduling information for each data stream is independently provided, though some scheduling flexibility may be lost to achieve such compactness.

As a still further possibility, it may be possible to at least partially reuse an existing DCI format, but with different MIMO layer/codeword mapping to support scheduling the data streams. For example, different layers can be mapped to different TRPs, different codewords can be mapped to different TRPs. Note that to support such mappings between layers/codewords and data streams, it may be useful to provide more options / a more flexible mapping between layers and codewords, e.g., in comparison to a current NR arrangement in which <NUM> codeword is allocated for up to <NUM> MIMO layers and <NUM> codewords are allocated otherwise.

Note that it may be possible for multiple such single DCI formats to be supported, and for support for switching between such DCI formats to be supported, e.g., by way of radio resource control (RRC) signaling, media access control (MAC) control element (CE) signaling, or via DCI itself. As another possibility, a NCJT DCI format used by a cellular base station could be signaled as part of system information (e.g., in one or more system information blocks (SIBs)).

Note that for a single DCI format, the quasi-collocated (QCL) configuration may be independently configured for each TRP. QCL may allow a UE to assume that two RS share the similar channel properties (e.g., delay, doppler, etc.). Thus, since the streams from the different TRPs may generally have different channel properties, each TRP may be configured with different DMRS ports (e.g., a group of DMRS ports), and QCL information regarding DMRS that belong to each TRP, and the corresponding CSI-RS, may be independently configured. This may allow a UE to determine which CSI-RS and PDSCH/DMRS transmissions are QCL, such as illustrated in <FIG>.

It may also be useful to support NCJT operation mode switching, e.g., such that the network is allowed to schedule a single TRP or two TRP to a UE dynamically. The DCI size for single TRP and two TRP scheduling may differ. The network can configure independent DCI for single TRP and two TRP scheduling. The single DCI can contain an explicit field that indicates which TRP is being scheduled. In some instances, a single DCI format may include a mechanism to disable a TRP by setting a selected DCI field (e.g., resource allocation, MCS/RV/NDI, etc.) to a reserved value, thereby implicitly indicating that the TRP indicated as being scheduled is actually being disabled.

As previously noted, a multi stage downlink DCI design for NCJT may also be possible. <FIG> illustrates exemplary aspects of one such possible multi stage downlink DCI design. In such a design, a first (e.g., main) DCI portion of the downlink control information may contain partial information for scheduling the two data streams, while a second (e.g., additional) DCI portion of the downlink control information may provide the remainder of the scheduling information, such that the full scheduling information may be available once both DCI portions have been decoded. The two DCIs may be provided by the same TRP or by different TRPs, which may in either case coordinate scheduling, as shown in <FIG>.

As one possibility, the first DCI may contain all of the scheduling information for the data stream for one of the TRPs, as well as an extra field to indicate the presence of the second TRP and the additional DCI that will provide additional scheduling information for scheduling the data stream for the other of the TRPs. The extra field can also provide further details on the DCI configuration for the second DCI, e.g., regarding the control resource set (CORESET), aggregation level, etc., to assist the UE with decoding the second DCI.

In some instances, the second DCI can have a smaller size, e.g., as common information with the first DCI may be omitted. For example, carrier ID information, bandwidth part (BWP) information, resource allocation, rate matching, virtual resource block (VRB) mapping, physical resource block (PRB) bundling, and/or any of various other parameters could be omitted from the second DCI portion, e.g., if they are the same for the second data stream as indicated in the first DCI portion for the first data stream.

In some instances, it may be possible for the first DCI portion and the second DCI portion to have resource (e.g., frequency and/or time) allocations that are implicitly linked, such that once the first DCI portion has been decoded, a UE can readily determine the resource allocation for the second DCI portion. For example, a time division multiplexing approach in which the two DCI occupy the same frequency resource(s) in adjacent symbols could be used. As another possibility, a frequency division multiplexing approach in which the two DCI occupy adjacent frequency resources in the same symbol(s) could be used. Examples of such possible implicit resource allocation linkages are also illustrated in <FIG>.

As previously noted, a downlink DCI design for NCJT in which multiple DCI are provided is also possible, e.g., such that each DCI schedules the data stream from the corresponding TRP independently. <FIG> illustrate exemplary aspects of one such possible multiple downlink DCI design. As shown, in such a design, a first DCI provided by a first TRP may schedule a first data stream to the UE, while a second DCI provided by a second TRP may schedule a second data stream to the UE.

Such a configuration may be possible when the TRPs are not able to dynamically coordinate scheduling decisions, e.g., due to backhaul delays, and may thus be more practical in such scenarios, at least in some instances. Since the TRPs may not dynamically coordinate scheduling decisions, it may be the case that DMRS (e.g., up to <NUM> ports) and CSI-RS (e.g., up to <NUM> ports) configurations may be semi-statically configured/partitioned between the TRPs, possibly in a manner transparent to the UE. As another possibility, the semi-static partitioned DMRS ports can be signaled to the UE to reduce DCI size.

The CORESET and search space can be independently configured for each DCI. This may facilitate coexistence between NCJT and non-NCJT operation, and reduce required UE complexity. In some instances, the resource allocations for the two DCI can be implicitly linked, e.g., as shown in <FIG>, in a time division multiplexing manner, in a frequency division multiplexing manner, or in any of various other possible ways of implicitly linking the resource allocations for the two DCI.

As shown in <FIG>, in some instances each DCI may include an extra field (E) to indicate the existence of the other DCI. Providing such an indicator may help reduce the DCI decoding complexity e.g., by providing more details on DCI configuration, such as CORESET, aggregation level, etc., for the other DCI. Additionally or alternatively, such an indicator may help facilitate detection of DCI misdetection errors, e.g., by enabling the UE to determine when a DCI is provided but not decoded.

Note that the two DCI may have different sizes. For example, the first DCI may schedule the first TRP, including the common scheduling information between the first TRP and the second TRP. The second DCI may schedule the second TRP with only the incremental information, e.g., such that common information may be omitted. Depending on the configuration, any or all of carrier ID, BWP ID, resource allocation, rate matching, VRB mapping, PRB bundling, etc., may thus be included in the common information provided in the first DCI (e.g., if the same for both data streams) or may be included in both the first DCI and the second DCI (e.g., if different for the different data streams).

For uplink DCI, similar format possibilities may be possible as for downlink DCI, at least according to some embodiments. For example, as one possibility, a single DCI design may be used, in which a single DCI schedules an uplink data stream. <FIG> illustrates exemplary aspects of one such possible single uplink DCI design. In such an arrangement, the multiple TRPs can serve as distributed reception points to enhance PUSCH decoding performance.

As another possibility, a two stage uplink DCI may be used. The first stage DCI may schedule a first uplink data stream, potentially including the common scheduling information between the first uplink data stream and a second uplink data stream. The first stage DCI may also indicate the existence of a second stage DCI. The second stage DCI may schedule the incremental scheduling information for the second uplink data stream.

As still another possibility, two separate uplink DCI may be used. Each DCI may schedule an uplink data stream corresponding to an individual TRP independently.

A new transmission configuration indicator (TCI) is provided for uplink DCI communications. The TCI may indicate a CSI-RS/SSB index. The UE may in turn use the corresponding receive beam associated with the CSI-RS/SSB index to transmit the uplink data stream. Thus, it may be possible for multiple uplink data streams to be configured with different beam configurations, e.g., as uplink streams corresponding to different TRPs may be configured with different TCI or sounding reference symbol (SRS) index (SRI) values. <FIG> illustrates exemplary aspects of such a configuration in which multiple uplink data streams having different beam configurations are transmitted by a UE.

NCJT operation may increase throughput for UE devices, while also generally increasing UE complexity and power consumption. For example, the UE may be expected to monitor multiple DCI and decode multiple physical downlink shared channels (PDSCH) simultaneously, and may need to activate multiple antenna panels in order to receive the multiple PDSCH. It may be the case that only a portion of UEs support NCJT operation, e.g., at least initially. Accordingly, it may be useful to provide a mechanism for indicating whether a UE supports NCJT. <FIG> illustrates exemplary aspects of such an arrangement in which a UE can indicate that it supports NCJT operation.

Additionally, given the increased complexity and power consumption of NCJT operation, a UE that is capable of NCJT operation may not always wish to enable NCJT operation. Thus, it may further be useful to provide a mechanism for a UE to signal a request to activate or deactivate NCJT for any of various reasons, such as the UE uplink buffer status (e.g., if it is lower or higher than a threshold for a certain period of time), UE battery status, UE thermal status, etc. Support for such signaling could be provided by use of temporary capability support signaling, e.g., to indicate whether a UE supports NCJT, and/or simultaneous operation of multiple antenna panels. Such signaling could be interpreted as a request (e.g., to activate NCJT if support is indicated by the UE, or to deactivate NCJT if support is not indicated by the UE) by the network.

The network may also have discretion as to whether to activate or deactivate NCJT dynamically. Such activation/deactivation could be implemented via RRC signaling, MAC-CE signaling, and/or via DCI signaling.

If desired, the network could also configure measurement reports to help with the decision whether to activate or deactivate NCJT. For example, at least according to some embodiments, NCJT operation may be most effective when the difference between signal strength/quality for two TRPs is relatively small at a UE, and may be less effective when the difference between signal strength/quality for two TRPs is relatively large. Thus, a UE could be configured to report when the measurement difference for two TRPs is within a threshold (hysteresis) for a certain period of time (time to trigger), which could be taken under consideration as an indicator in favor of activating (or conversely against deactivating) NCJT by the network. Similarly, a UE could be configured to report when the measurement difference for two TRPs exceeds a threshold (hysteresis) for a certain period of time (time to trigger), which could be taken under consideration as an indicator in favor of deactivating (or conversely against activating) NCJT by the network. <FIG> illustrates how such a reporting mechanism might proceed in an exemplary possible UE mobility scenario, as an example.

The network could also or alternatively configure UE reporting when the UE uplink buffer is lower than a certain threshold, and/or higher than a certain (e.g., same or different) threshold, for a certain period of time, as an indicator regarding whether to activate/deactivate NCJT operation for the UE. The network may also or alternatively consider the downlink buffer status (e.g., similarly whether its size is lower or higher than one or more thresholds for a certain period of time) for a UE as an indicator regarding whether to activate/deactivate NCJT operation for the UE.

Note that activation and deactivation of NCJT can be configured independently for each BWP for a UE, if desired.

When NCJT operation is activated, each TRP may have its own independent HARQ entity (with each HARQ entity containing multiple HARQ processes), at least according to some embodiments. For each data stream scheduling, the DCI may indicate a TRP index, which can be used to schedule cross TRP retransmissions, if desired.

Note that independent receive and transmit beam configurations can be used for the PDSCH/PUSCH corresponding to an individual TRP. Thus, each PDSCH can be configured with its own TCI, and each PUSCH can be configured with its own SRI.

Claim 1:
A method comprising, by a processor (<NUM>) of a wireless device (<NUM>):
receiving (<NUM>) first downlink control information, DCI, scheduling a first data stream of a first non coherent joint transmission uplink data communication,
receiving (<NUM>) second DCI scheduling a second data stream of a second non coherent joint transmission uplink data communication, wherein transmission of the first and second non coherent joint transmission uplink data streams include simultaneous transmission using two transmission beams; and
transmitting (<NUM>) the first and second data streams according the respective scheduling of the first and second DCI using a <NUM>rd Generation Partnership Project, 3GPP, radio access technology, RAT;
wherein respective physical uplink shared channels, PUSCHs, of the first and second data streams are configured with distinct transmitter configuration indices, TCIs, in the respective scheduling of the first and second DCI.