Reference signal parameter modification for improved channel estimation in wireless communication systems

Abstract

Methods, systems and devices for modifying reference signal parameters to improve channel estimation in mobile communication technologies are described. An example method for wireless communication includes transmitting a reference signal by a first communication node to a second communication node, at least one parameter of the reference signal having been modified based on a downlink control information (DCI) format message or a medium access control (MAC) message, and the at least one parameter includes one or more of the following: a number of orthogonal frequency division multiplexing (OFDM) symbols in the reference signal, a number of OFDM symbols in the reference signal in a frequency domain range, a time domain position of a first symbol of the reference signal, and a number of repetition transmissions of the reference signal.

Description

Technical Field

[0001] This document relates generally to wireless communications. Background Art

[0002] Wireless communication technology is driving the world towards an increasingly connected and networked society. The rapid growth of wireless communications and technological advances have led to greater demands for capacity and connectivity. Other aspects such as energy consumption, equipment cost, spectrum efficiency, and latency are also important to meet the needs of various communication scenarios. Compared with existing wireless networks, next-generation systems and wireless communication technologies will provide support for more users and devices, as well as support for higher data rates. Summary of the invention

[0003] This document relates to methods, systems and devices for modifying reference signal parameters to improve channel estimation in mobile communication technologies, including 5th Generation (5G) and New Radio (NR) communication systems.

[0004] In one exemplary aspect, a wireless communication method is disclosed. The method includes transmitting, by a first communication node, a reference signal to a second communication node, wherein at least one parameter of the reference signal has been modified based on a downlink control information (DCI) format message or a medium access control (MAC) message, and wherein the at least one parameter includes one or more of the number of orthogonal frequency division multiplexing (OFDM) symbols in the reference signal, the number of OFDM symbols in the reference signal in a frequency domain range, the time domain position of a first symbol of the reference signal, and the number of repetition transmissions of the reference signal.

[0005] In another exemplary aspect, a wireless communication method is disclosed. The method includes receiving, by a second communication node, a reference signal from a first communication node, wherein at least one parameter of the reference signal has been modified based on a downlink control information (DCI) format message or a medium access control (MAC) message, and wherein the at least one parameter includes one or more of the number of orthogonal frequency division multiplexing (OFDM) symbols in the reference signal, the number of OFDM symbols in the reference signal in a frequency domain range, the time domain position of a first symbol of the reference signal, and the number of repeated transmissions of the reference signal.

[0006] In another exemplary aspect, a wireless communication method is disclosed. The method includes transmitting a first reference signal and a second reference signal by a multiple-input multiple-output (MIMO) first communication node to a second communication node, wherein the first reference signal and the second reference signal are transmitted from a common antenna port, wherein at least one parameter of the second reference signal has been configured based on a radio resource control (RRC) message, a downlink control information (DCI) format message, or a medium access control (MAC) message, and wherein at least one parameter includes a number of repetitions of the second reference signal or a time domain position of a first symbol of the second reference signal with respect to the first reference signal.

[0007] In another exemplary aspect, a wireless communication method is disclosed. The method includes receiving, by a second communication node, a first reference signal and a second reference signal from a multiple-input multiple-output (MIMO) first communication node, wherein the first reference signal and the second reference signal are configured to be transmitted from a common antenna port, wherein at least one parameter of the second reference signal has been configured based on a radio resource control (RRC) message, a downlink control information (DCI) format message, or a medium access control (MAC) message, and wherein at least one parameter includes a number of repetitions of the second reference signal or a time domain position of a first symbol of the second reference signal with respect to the first reference signal.

[0008] In yet another exemplary aspect, the above method is embodied in the form of processor executable code and stored in a computer readable program medium.

[0009] In yet another exemplary embodiment, a device configured or operable to perform the above method is disclosed.

[0010] The above and other aspects and implementations thereof are described in more detail in the drawings, the description and the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 Examples of a base station (BS) and a user equipment (UE) in wireless communications according to some embodiments of the disclosed technology are shown.

[0012] Figure 2 An example of a wireless communication method according to some embodiments of the disclosed technology is shown.

[0013] Figure 3 Another example of a wireless communication method according to some embodiments of the disclosed technology is shown.

[0014] Figure 4 Another example of a wireless communication method according to some embodiments of the disclosed technology is shown.

[0015] Figure 5Another example of a wireless communication method according to some embodiments of the disclosed technology is shown.

[0016] Figure 6 is a block diagram representation of a portion of an apparatus that may be configured to implement embodiments of the disclosed technology. DETAILED DESCRIPTION

[0017] Wireless communication is ubiquitous in daily life and industry. The 5th Generation New Radio (5G NR) wireless communication network is designed based on OFDM technology. The time domain structure of OFDM transmission includes a radio frame consisting of multiple time slots, each of which consists of multiple OFDM symbols. The frequency domain structure of OFDM transmission is divided into resource blocks (RBs), each of which has a certain number of subcarriers.

[0018] In this generation of communication networks, base stations (BSs) and terminals use channel estimation to generate an estimate of a channel, which is used to demodulate and decode received signals. The BS or terminal can estimate the channel by transmitting a reference signal (RS) to estimate the channel.

[0019] Figure 1 An example of a wireless communication system (e.g., an LTE, 5G, or New Radio (NR) cellular network) including a BS 120 and one or more user equipment (UE) 111, 112, and 113 is shown. In some embodiments, downlink transmissions (141, 142, 143) include one or more reference signals. In response, each UE performs channel estimation using the reference signals and then performs subsequent transmissions (131, 132, 133, respectively) to the BS 120 that have taken into account changes in the wireless channel. The UE can be, for example, a smartphone, a tablet, a mobile computer, a machine-to-machine (M2M) device, a terminal, a mobile device, an Internet of Things (IoT) device, etc.

[0020] This document uses examples from the 3GPP New Radio (NR) network architecture and 5G protocols only to facilitate understanding, and the disclosed techniques and embodiments can be practiced in other wireless systems that use communication protocols different from the 3GPP protocols.

[0021] exist Figure 1In the example shown, the transmission parameters of the reference signal (e.g., 141, 142, 143) are configured by the base station, for example, through radio resource control (RRC) signaling. However, the wireless channel between BS 120 and UE (111, 112 and 113) is typically a time-varying channel, which may be susceptible to fading. Therefore, when the wireless channel is in a fading period, the transmitted reference signal has been configured based on the previous channel condition (and using the previous transmission parameters). The signal-to-noise ratio (SNR) of the received reference signal is typically low, resulting in poor channel estimation accuracy, and thus a transmission scheme that matches the current channel condition cannot be generated. Similarly, when data demodulation is performed using a low-accuracy channel estimate, data demodulation performance is also reduced.

[0022] Examples of reference signals include channel state information reference signal (CSI-RS), data demodulation reference signal (DMRS), sounding reference signal (SRS), etc. The received signal-to-noise ratio (SNR) of the reference signal directly affects the estimation accuracy of the channel, thereby affecting the performance of the transmission scheme and the data demodulation performance.

[0023] According to their time domain characteristics, reference signals are divided into three types: periodic, semi-persistent and aperiodic (or irregular). In some embodiments (e.g., periodic scheduling), the base station configures the transmission parameters of the reference signal through radio resource control (RRC) signaling, after which the reference signal is transmitted in a periodic manner using these parameters. In other embodiments (e.g., semi-persistent scheduling), the reference signal is transmitted using the configured transmission parameters after an activation instruction is transmitted through medium access control (MAC) signaling, and its transmission stops when a deactivation instruction is transmitted. In some other embodiments (e.g., irregular scheduling), the reference signal is transmitted using the configured parameters when triggered by information carried in a downlink control information (DCI) format message.

[0024] Embodiments of the disclosed technology are directed to modifying parameters of a reference signal, which is then transmitted and used to improve the accuracy of channel estimation.

[0025] In some embodiments, the first communication node (e.g., Figure 1 BS 120 in the example) sends a signal to a second communication node (eg, Figure 1The first communication node receives the first reference signal transmitted by the second communication node according to the configured transmission parameters.

[0026] Since the wireless channel is a time-varying channel, the transmission parameters of the reference signal configured by RRC signaling may not match the current wireless channel conditions. An exemplary solution to this problem requires the first communication node to modify the transmission parameters of the first reference signal (or add additional transmission parameters to the first reference signal) through signaling. In one example, the transmission parameters of the first reference signal can be modified using downlink control information (DCI) format signaling or medium access control (MAC) signaling. By modifying the transmission parameters of the first reference signal, the transmission of the first reference signal can be matched to the current wireless channel state.

[0027] In some embodiments, the following may be implemented to attempt to match the transmission parameters to the current wireless channel:

[0028] o modifying the number of OFDM symbols used for the first reference signal by increasing or decreasing the number of OFDM symbols,

[0029] o modifying the number of OFDM symbols that the receiving end can use for channel estimation, thereby controlling the SNR of the received reference signal and achieving the desired quality of the control channel estimation,

[0030] o modifying the number of OFDM symbols (eg, the number of subcarriers or RBs) used by the first reference signal in the frequency domain,

[0031] o changing the transmission of reference signals on different OFDM symbols and the frequency domain position of the reference signals in order to estimate the channel performance in a specific frequency domain, since the reference signals use multiple OFDM symbols in the same frequency domain,

[0032] ο modifying the number of OFDM symbols used by the reference signal in a specific frequency domain to avoid degradation of channel estimation performance within a specific frequency range due to changes in the wireless channel, and

[0033] o Modify the time domain starting position of the first OFDM symbol of the first reference signal to avoid interference and avoid interference of the first reference signal on other signals.

[0034] In some embodiments, one of the parameters that can be modified or indicated by signaling includes the number of times the first reference signal is transmitted. The number of times the first reference signal is transmitted can be changed to avoid degradation of channel estimation performance because the reference signal from each transmission can be combined to perform channel estimation.

[0035] In some embodiments, the number of times the first reference signal is transmitted may be indicated by:

[0036] (1) Indicates that the first reference signal is to be transmitted M times within a certain time period, where M is an integer greater than 1.

[0037] (2) When the first reference signal is a periodic reference signal, it indicates that the first reference signal is transmitted K times in each cycle (time period) of N consecutive cycles.

[0038] (3) Indicates that the first reference signal is transmitted M times continuously one by one on the available OFDM symbols.

[0039] (4) Indicates the time interval between adjacent transmissions of the first reference signal.

[0040] (5) Indicates the number of times the first reference signal is transmitted in one time slot.

[0041] In some embodiments, the first communication node modifies the transmission parameters of the first reference signal by signaling, and further includes an identifier indicating the modified first reference signal. The identifier of the first reference signal is used to indicate that the transmission parameters of a specific reference signal have been modified.

[0042] In some embodiments, the first communication node informs the second communication node of the configuration of the second reference signal via radio resource control (RRC) signaling. In one example, the configuration parameters include: an identifier of the second reference signal and an association of the second reference signal with the first reference signal.

[0043] In some embodiments, the first communications node triggers transmission of the second reference signal through downlink control information (DCI) format signaling or medium access control (MAC) signaling, and also indicates transmission parameters of the second reference signal.

[0044] In other embodiments, the first communication node informs the second communication node of the configuration of the second reference signal through radio resource control (RRC) signaling.Herein, the configuration parameters include an identifier of the second reference signal and the second reference signal is associated with the first reference signal.

[0045] In some further embodiments, the first communication node triggers transmission of the second reference signal through downlink control information (DCI) format signaling or medium access control (MAC) signaling, indicates transmission parameters of the second reference signal, and further indicates that the first reference signal is associated with the second reference signal.

[0046] In some further embodiments, the first communication node notifies the second communication node of the configuration of the second reference signal through RRC signaling. Herein, the configuration parameter includes an identifier of the second reference signal.

[0047] In other embodiments, the first communication node triggers transmission of the second reference signal through DCI format signaling or MAC signaling, and the DCI format signaling or MAC signaling indicates transmission parameters of the second reference signal and further indicates that the first reference signal is associated with the second reference signal.

[0048] In the embodiments described herein, the association between the first reference signal and the second reference signal is in a multiple-input multiple-output (MIMO) system, and means that the second reference signal and the first reference signal are transmitted from a common antenna port. Since the second reference signal and the first reference signal are transmitted through a common antenna port, they belong to the same wireless channel. Therefore, the receiving end can perform a joint channel estimation operation on the second reference signal and the first reference signal, thereby improving the channel estimation performance.

[0049] In some embodiments, the first communication node notifies the second communication node of the configuration of the second reference signal via RRC signaling, and the configuration parameters also include an indication that the second reference signal is being repeated with respect to the first reference signal (i.e., associated with the first reference signal). Among other benefits, configuring the repetition factor (R>1) for the second reference signal advantageously ensures that the transmission parameters of the second reference signal and the second reference signal itself are robustly and accurately received.

[0050] In some embodiments, the first communication node indicates the transmission parameters of the second reference signal through DCI format signaling or MAC signaling. The indicated transmission parameters of the second reference signal include an indication of whether the associated first reference signal is repeated and an indication of the OFDM symbol where the reference signal is located.

[0051] In some embodiments, the second reference signal is configured to repeat a portion of the first reference signal, and the repeated portion of the first reference signal may be indicated by indicating an OFDM symbol at which the first reference signal is repeated.

[0052] In some embodiments, the indicated transmission parameter of the second reference signal includes the number of times the second reference signal is repeated with respect to the associated first reference signal. In one example, it may be necessary to repeat the second reference signal multiple times to avoid degradation of channel estimation performance. Therefore, providing an indication of the number of times the second reference signal is repeated can improve channel estimation and subsequently achieve better data demodulation performance.

[0053] In some embodiments, the indicated transmission parameters of the second reference signal also include the starting OFDM symbol where the second reference signal is located. The starting OFDM symbol where the second reference signal is located is determined by the starting OFDM symbol where the associated first reference signal is located. In one example, the starting OFDM symbol of the second reference signal may be located in the same time slot as the starting OFDM symbol of the first reference signal. In another example, the starting OFDM symbol of the second reference signal may be located at the next available time slot of the time slot of the starting OFDM symbol of the first reference signal. The obtainable time slot refers to a time slot that can be used to transmit a reference signal. In another example, the starting OFDM symbol of the second reference signal is located next to an OFDM symbol that can be obtained from the starting OFDM symbol of the first reference signal. In another example, the position of the starting OFDM symbol of the first reference signal is used as a reference, and the second reference signal is transmitted every K OFDM symbols on the available OFDM symbol. In another example, the position of the time slot of the first reference signal is used as a reference, and the second reference signal is transmitted every K time slots on the available time slot. In yet another example, the first reference signal is divided into two parts - a second reference signal part repeating the first part of the first reference signal is transmitted before the first reference signal, and a second reference signal part repeating the second part of the first reference signal is transmitted after the first reference signal.

[0054] Based on the described embodiments of the technology disclosed in this disclosure, the following exemplary technical solutions can be implemented:

[0055] (1) The first communication node modifies the transmission parameters of the first reference signal (or adds / indicates new or previously unused transmission parameters) through signaling.

[0056] (2) Modify the number of OFDM symbols used by the first reference signal.

[0057] (3) Modifying the number of OFDM symbols (eg, the number of subcarriers or RBs) used by the first reference signal in the frequency domain.

[0058] (4) Modify the time domain position of the starting OFDM symbol of the first reference signal.

[0059] (5) Modify or add the number of times the first reference signal is transmitted.

[0060] (6) The indication of the number of times the first reference signal is transmitted may be:

[0061] (a) An indication that the first reference signal is transmitted M times within a certain period of time, where M is an integer greater than 1.

[0062] (b) Assuming the first reference signal is a periodic reference signal, an indication that the first reference signal is transmitted K times in each of N consecutive time periods.

[0063] (c) An indication that the first reference signal is transmitted M times consecutively one after another on the available OFDM symbols.

[0064] (d) An indication of the time interval between adjacent transmissions of the first reference signal.

[0065] (e) An indication of the number of times the first reference signal is transmitted in a time slot.

[0066] (7) The first communication node modifies or adds transmission parameters of the first reference signal through signaling, and also includes (eg, as part of the signaling) an identifier indicating the modified first reference signal.

[0067] (8) The first communication node notifies the second communication node of the configuration of the second reference signal through RRC signaling, and the configuration parameters include an identifier of the second reference signal, and the second reference signal is associated with the first reference signal.

[0068] (9) The first communication node notifies the second communication node of the configuration of the second reference signal through RRC signaling, and the configuration parameters also include an indication that the second reference signal is being repeated with respect to the associated first reference signal.

[0069] (10) The first communication node indicates transmission parameters of the second reference signal through DCI format signaling or MAC signaling, and the indicated transmission parameters of the second reference signal include an indication of whether the associated first reference signal is repeated and an indication of the OFDM symbol where the reference signal is located.

[0070] (11) The indicated transmission parameter of the second reference signal includes the number of times the second reference signal repeats the associated first reference signal.

[0071] (12) The indicated transmission parameters of the second reference signal also include a starting OFDM symbol where the second reference signal is located.

[0072] (13) The starting OFDM symbol where the second reference signal is located is determined by the starting OFDM symbol where the associated first reference signal is located.

[0073] Figure 2An example of a wireless communication method 200 for modifying reference signal parameters to improve channel estimation is shown. The method 200 includes: at operation 210, a reference signal is transmitted by a first communication node to a second communication node, at least one parameter of the reference signal has been modified based on a downlink control information (DCI) format message or a medium access control (MAC) message, and the at least one parameter includes one or more of the number of orthogonal frequency division multiplexing (OFDM) symbols in the reference signal, the number of OFDM symbols in the reference signal in the frequency domain range, the time domain position of the first symbol of the reference signal, and the number of repeated transmissions of the reference signal.

[0074] Figure 3 An example of a wireless communication method 300 for modifying reference signal parameters to improve channel estimation is shown. The method 300 includes: at operation 310, a reference signal is received by a second communication node from a first communication node, at least one parameter of the reference signal has been modified based on a downlink control information (DCI) format message or a medium access control (MAC) message, and the at least one parameter includes one or more of the number of orthogonal frequency division multiplexing (OFDM) symbols in the reference signal, the number of OFDM symbols in the reference signal in the frequency domain range, the time domain position of the first symbol of the reference signal, and the number of repeated transmissions of the reference signal.

[0075] Figure 4 An example of a wireless communication method 400 for modifying reference signal parameters to improve channel estimation is shown. The method 400 includes: at operation 410, a first reference signal and a second reference signal are transmitted from a first communication node of a multiple-input multiple-output (MIMO) to a second communication node, the first reference signal and the second reference signal are transmitted from a common antenna port, at least one parameter of the second reference signal has been configured based on a radio resource control (RRC) message, a downlink control information (DCI) format message, or a medium access control (MAC) message, and the at least one parameter includes a number of repetitions of the second reference signal or a time domain position of a first symbol of the second reference signal with respect to the first reference signal.

[0076] Figure 5 An example of a wireless communication method 500 for modifying reference signal parameters to improve channel estimation is shown. The method 500 includes: at operation 510, a first reference signal and a second reference signal are received by a second communication node from a multiple-input multiple-output (MIMO) first communication node, the first reference signal and the second reference signal are configured to be transmitted from a common antenna port, at least one parameter of the second reference signal has been configured based on a radio resource control (RRC) message, a downlink control information (DCI) format message, or a medium access control (MAC) message, and the at least one parameter includes a number of repetitions of the second reference signal or a time domain position of a first symbol of the second reference signal with respect to the first reference signal.

[0077] In some embodiments, the following technical solutions can be implemented:

[0078] A1. A method for wireless communication, comprising: transmitting a reference signal by a first communication node to a second communication node, wherein at least one parameter of the reference signal has been modified based on a downlink control information (DCI) format message or a medium access control (MAC) message, and wherein at least one parameter includes one or more of the number of orthogonal frequency division multiplexing (OFDM) symbols in the reference signal, the number of OFDM symbols in the reference signal in a frequency domain range, the time domain position of a first symbol of the reference signal, and the number of repeated transmissions of the reference signal.

[0079] A2. A method for wireless communication, comprising: receiving a reference signal from a first communication node by a second communication node, wherein at least one parameter of the reference signal has been modified based on a downlink control information (DCI) format message or a medium access control (MAC) message, and wherein at least one parameter includes one or more of the following: the number of orthogonal frequency division multiplexing (OFDM) symbols in the reference signal, the number of OFDM symbols in the reference signal in a frequency domain range, the time domain position of the first symbol of the reference signal, and the number of repeated transmissions of the reference signal.

[0080] A3. The method according to scheme A2 also includes: performing a channel estimation operation based on a reference signal.

[0081] A4. A method according to any one of schemes A1 to A3, wherein an indication corresponding to the number of repeated transmissions is signaled in a DCI message or a MAC message.

[0082] A5. A method according to scheme A4, wherein the indication includes a number of times (M) the reference signal is repeated within a predetermined time period, wherein M is an integer greater than 1.

[0083] A6. A method according to scheme A4, wherein the reference signal comprises a periodic reference signal, wherein the indication comprises the number of times (K) the reference signal is repeated in each of N consecutive time periods, and wherein K and N are positive integers.

[0084] A7. A method according to scheme A4, wherein the indication includes the number of times (M) the reference signal is repeated consecutively over the available OFDM symbols.

[0085] A8. A method according to scheme A4, wherein the indication includes a time interval between adjacent transmissions of the reference signal.

[0086] A9. A method according to scheme A4, wherein the indication includes the number of times (K) the reference signal is repeated in the time slot.

[0087] A10. A method according to any one of schemes A1 to A3, wherein the DCI message or the MAC message further includes an identifier corresponding to the reference signal.

[0088] A11. A method according to any one of schemes A1 to A10, wherein the first communication node is a network node and the second communication node is a wireless device.

[0089] A12. A method according to scheme A11, wherein the reference signal is a channel state information reference signal (CSI-RS), a demodulation reference signal (DMRS) or a phase tracking reference signal (PTRS).

[0090] A13. A method according to any one of schemes A1 to A10, wherein the first communication node is a wireless device and the second communication node is a network node.

[0091] A14. A method according to scheme A13, wherein the reference signal is a sounding reference signal (SRS), a demodulation reference signal (DMRS) or a phase tracking reference signal (PTRS).

[0092] A15. A method for wireless communication, comprising: transmitting a first reference signal and a second reference signal by a multiple-input multiple-output (MIMO) first communication node to a second communication node, wherein the first reference signal and the second reference signal are transmitted from a common antenna port, wherein at least one parameter of the second reference signal has been configured based on: a radio resource control (RRC) message, a downlink control information (DCI) format message, or a medium access control (MAC) message, and wherein at least one parameter includes the number of repetitions of the second reference signal or the time domain position of the first symbol of the second reference signal relative to the first reference signal.

[0093] A16. A method for wireless communication, comprising: receiving, by a second communication node, a first reference signal and a second reference signal from a multiple-input multiple-output (MIMO) first communication node, wherein the first reference signal and the second reference signal are configured to be transmitted from a common antenna port, wherein at least one parameter of the second reference signal has been configured based on: a radio resource control (RRC) message, a downlink control information (DCI) format message, or a medium access control (MAC) message, and wherein at least one parameter includes the number of repetitions of the second reference signal or the time domain position of a first symbol of the second reference signal relative to the first reference signal.

[0094] A17. The method according to scheme A16 also includes: performing a joint channel estimation operation based on the first reference signal and the second reference signal.

[0095] A18. A method according to any one of schemes A15 to A17, wherein the first communication node is a network node and the second communication node is a wireless device.

[0096] A19. A method according to scheme A18, wherein the first reference signal is a channel state information reference signal (CSI-RS), a demodulation reference signal (DMRS) or a phase tracking reference signal (PTRS).

[0097] A20. A method according to any one of schemes A15 to A17, wherein the first communication node is a wireless device and the second communication node is a network node.

[0098] A21. A method according to scheme A20, wherein the first reference signal is a sounding reference signal (SRS), a demodulation reference signal (DMRS) or a phase tracking reference signal (PTRS).

[0099] A22. A wireless communication device, comprising a processor and a memory, wherein the processor is configured to read a code from the memory and implement a method according to any one of schemes A1 to A21.

[0100] A23. A computer program product, comprising a computer-readable program medium code stored thereon, which, when executed by a processor, causes the processor to implement the method according to any one of schemes A1 to A21.

[0101] Figure 6 605 is a block diagram representation of a portion of an apparatus according to some embodiments of the disclosed technology. An apparatus 605, such as a base station or a wireless device (or UE), may include a processor electronic device 610, such as a microprocessor, which implements one or more of the technologies presented in this document. The apparatus 605 may include a transceiver electronic device 615 for sending and / or receiving wireless signals through one or more communication interfaces such as (multiple) antennas 620. The apparatus 605 may include other communication interfaces for transmitting and receiving data. The device 605 may include one or more memories (not explicitly shown) configured to store information such as data and / or instructions. In some implementations, the processor electronic device 610 may include at least a portion of the transceiver electronic device 615. In some embodiments, at least some of the disclosed techniques, modules, or functions are implemented using the apparatus 605.

[0102] Some of the embodiments described herein are described in the general context of a method or process, which in one embodiment can be implemented by a computer program product embodied in a computer-readable medium, which includes computer-executable instructions, such as program code, executed by a computer in a network environment. Computer-readable media may include removable and non-removable storage devices, including but not limited to read-only memory (ROM), random access memory (RAM), compact disk (CD), digital versatile disk (DVD), etc. Therefore, computer-readable media may include non-transitory storage media. Typically, program modules may include routines, programs, objects, components, data structures, etc. that perform specific tasks or implement specific abstract data types. Computer or processor executable instructions, related data structures, and program modules represent examples of program codes for executing the steps of the methods disclosed herein. A specific sequence of such executable instructions or related data structures represents an example of corresponding actions for implementing the functions described in such steps or processes.

[0103] Some of the disclosed embodiments can be implemented as a device or module using hardware circuits, software, or a combination thereof. For example, a hardware circuit implementation can include discrete analog and / or digital components, such as integrated as a part of a printed circuit board. Alternatively or additionally, the disclosed components or modules can be implemented as application specific integrated circuits (ASICs) and / or field programmable gate arrays (FPGAs) devices. Some implementations can additionally or alternatively include a digital signal processor (DSP), which is a dedicated microprocessor with an architecture optimized for the operational needs of digital signal processing associated with the disclosed functions of the present application. Similarly, various components or subcomponents within each module can be implemented with software, hardware, or firmware. The connection between the modules and / or the components within the modules can be provided using any of the connection methods and media known in the art, including but not limited to using appropriate protocols.

[0104] Although this document contains many details, these should not be interpreted as limitations on the scope of the claimed invention or what may be claimed, but rather as descriptions of specific features of specific embodiments. Certain features described in this document in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, the various features described in the context of a single embodiment may also be implemented in multiple embodiments individually or in any suitable sub-combination. In addition, although features may be described above as working in certain combinations and even initially claimed as such, one or more features may be removed from the claimed combination in some cases, and the claimed combination may involve a sub-combination or a variant of a sub-combination. Similarly, although operations are depicted in a particular order in the accompanying drawings, this should not be understood as requiring that these operations be performed in the particular order shown or in sequence, or that all of the operations shown be performed to obtain the desired result.

[0105] Only a few implementations and examples are described, and other implementations, enhancements, and variations can be made based on what is described and illustrated in this disclosure.

Claims

1. A method for wireless communication, comprising: The first communication node receives a downlink control information DCI format message or a medium access control MAC message from the second communication node; The first communication node transmits a reference signal to the second communication node, wherein at least one parameter of the reference signal has been modified based on the DCI format message or the MAC message, and The at least one parameter includes a time domain position of a first symbol of the reference signal and a number of repeated transmissions of the reference signal.

2. A method for wireless communication, comprising: The second communication node transmits a downlink control information DCI format message or a medium access control MAC message to the first communication node; receiving, by the second communication node, a reference signal from the first communication node, wherein at least one parameter of the reference signal has been modified based on the DCI format message or the MAC message, and The at least one parameter includes a time domain position of a first symbol of the reference signal and a number of repeated transmissions of the reference signal.

3. The method according to claim 2, further comprising: A channel estimation operation is performed based on the reference signal.

4. The method according to any one of claims 1 to 3, wherein an indication corresponding to the number of repeated transmissions is signaled in the DCI message or the MAC message. The method according to claim 4 , wherein the indication comprises a number M of times the reference signal is repeated within a predetermined time period, wherein M is an integer greater than 1.

6. The method of claim 4, wherein the reference signal comprises a periodic reference signal, wherein the indication comprises a number K of times the reference signal is repeated in each of N consecutive time periods, and wherein K and N are positive integers.

7. The method of claim 4, wherein the indication comprises a number of times M that the reference signal is repeated consecutively over available OFDM symbols.

8. The method of claim 4, wherein the indication comprises a time interval between adjacent transmissions of the reference signal.

9. The method of claim 4, wherein the indication comprises a number K of times the reference signal is repeated in a time slot.

10. The method according to any one of claims 1 to 3, wherein the DCI message or the MAC message further includes an identifier corresponding to the reference signal.

11. The method according to any one of claims 1 to 10, wherein the first communication node is a network node and the second communication node is a wireless device. 12 . The method according to claim 11 , wherein the reference signal is a channel state information reference signal (CSI-RS), a demodulation reference signal (DMRS), or a phase tracking reference signal (PTRS).

13. The method according to any one of claims 1 to 10, wherein the first communication node is a wireless device and the second communication node is a network node. The method according to claim 13 , wherein the reference signal is a sounding reference signal (SRS), a demodulation reference signal (DMRS), or a phase tracking reference signal (PTRS).

15. A method for wireless communication, comprising: Receiving, by a multiple-input multiple-output MIMO first communication node, a radio resource control RRC message, a downlink control information DCI format message, or a medium access control MAC message from a second communication node; The MIMO first communication node transmits a first reference signal and a second reference signal to the second communication node, The first reference signal and the second reference signal are transmitted from a common antenna port, wherein at least one parameter of the second reference signal has been configured based on: the RRC message, the DCI format message or the MAC message, and The at least one parameter comprises an indication of whether the second reference signal is being repeated with respect to the first reference signal, a number of repetitions of the second reference signal, and a time domain position of a first symbol of the second reference signal with respect to the first reference signal.

16. A method for wireless communication, comprising: The second communication node transmits a radio resource control RRC message, a downlink control information DCI format message, or a medium access control MAC message to the multiple-input multiple-output MIMO first communication node; receiving, by the second communication node, a first reference signal and a second reference signal from the MIMO first communication node, wherein the first reference signal and the second reference signal are configured to be transmitted from a common antenna port, wherein at least one parameter of the second reference signal has been configured based on: the RRC message, the DCI format message or the MAC message, and The at least one parameter comprises an indication of whether the second reference signal is being repeated with respect to the first reference signal, a number of repetitions of the second reference signal, and a time domain position of a first symbol of the second reference signal with respect to the first reference signal.

17. The method according to claim 16, further comprising: A joint channel estimation operation is performed based on the first reference signal and the second reference signal.

18. The method according to any one of claims 15 to 17, wherein the first communication node is a network node and the second communication node is a wireless device. 19 . The method according to claim 18 , wherein the first reference signal is a channel state information reference signal (CSI-RS), a demodulation reference signal (DMRS), or a phase tracking reference signal (PTRS).

20. The method according to any one of claims 15 to 17, wherein the first communication node is a wireless device and the second communication node is a network node. 21 . The method according to claim 20 , wherein the first reference signal is a sounding reference signal (SRS), a demodulation reference signal (DMRS), or a phase tracking reference signal (PTRS).

22. A wireless communication device comprising a processor and a memory, wherein the processor is configured to read a code from the memory and implement the method according to any one of claims 1 to 21.

23. A computer program product comprising computer readable program medium code stored thereon, which, when executed by a processor, causes the processor to implement the method according to any one of claims 1 to 21.

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