Reference signals with different resource densities

Abstract

A method of wireless communication includes transmitting an indication of N regions in a resource grid defined by transmission resources in a frequency domain and / or time resources in a time domain from a first communication device to a second communication device, and communicating a reference signal between the first communication device and the second communication device according to density information. Here, each of the N regions has a corresponding resource density indicating a density of time-frequency resources configured for reference signal transmission, and N is an integer greater than 1.

Description

[Technical Field]

[0001] This document relates to systems, devices, and techniques for wireless communications. [Background technology]

[0002] Efforts are currently underway to define next generation wireless communication networks that will provide greater deployment flexibility, support a greater number of devices and services, and offer a variety of techniques for efficient bandwidth utilization. Summary of the Invention [Means for solving the problem]

[0003] Various methods and apparatus are described for achieving different reference signal densities in a wireless communication system.

[0004] In one exemplary aspect, a method of wireless communication is disclosed. The method includes transmitting, from a first communication device to a second communication device, an indication of N regions in a resource grid defined by transmission resources in the frequency domain and / or time resources in the time domain, and communicating a reference signal between the first communication device and the second communication device according to the density information, where each of the N regions has a corresponding resource density indicating a density of time-frequency resources configured for reference signal transmission, and N is an integer greater than 1.

[0005] In another example aspect, a method of wireless communication is disclosed. The method includes receiving, by a second communication device from a first communication device, an indication of N regions in a resource grid defined by transmission resources in the frequency domain and / or time resources in the time domain, and communicating a reference signal between the first communication device and the second communication device according to the density information, where each of the N regions has a corresponding resource density indicating a density of time-frequency resources configured for reference signal transmission, and N is an integer greater than 1.

[0006] In yet another exemplary aspect, a wireless communication apparatus is disclosed comprising a processor configured to perform the methods described herein.

[0007] In other exemplary aspects, the various techniques described herein may be embodied as processor-executable code and stored on a computer-readable program medium.

[0008] The details of one or more implementations are set forth in the accompanying drawings and the description below. Other features will be apparent from the description and drawings, and from the claims. The present invention provides, for example, the following. (Item 1) 1. A method of wireless communication, comprising: transmitting from a first communication device to a second communication device an indication of N regions within a resource grid defined by transmission resources in the frequency domain and / or time resources in the time domain, each of the N regions has a corresponding resource density indicating a density of time-frequency resources configured for reference signal transmission; N is an integer greater than 1; and communicating a reference signal between the first communication device and the second communication device according to density information; A method comprising: (Item 2) further comprising configuring frequency resources in the frequency domain for each of the N regions; The frequency resource in the frequency domain is defined in units of resource blocks or resource block groups. The method according to item 1. (Item 3) Item 2. The method of item 1, wherein the density information signals the value of N. (Item 4) 4. The method according to items 2 to 3, wherein if the time resource is not indicated for a particular region, the resource density is interpreted as being applicable to all time units of the particular region. (Item 5) The method according to items 2 to 3, wherein if the time resource is not indicated with respect to a specific region, all time units transmitted by the first communication device or the second communication device are interpreted as being applicable to all time units of the specific region. (Item 6) and configuring, for each of the N regions, a time resource in the time domain, the time resource being defined for each region in units of transmission symbols or time slots. The method according to items 2 and 3. (Item 7) 7. The method according to any one of items 1 to 6, wherein the resource densities of the N regions are indicated using a scaling factor relative to the resource density of a reference region. (Item 8) 8. The method according to any one of items 1 to 7, wherein the resource density is indicated in a Medium Access Control (MAC) Control Element (CE). (Item 9) transmitting a reference signal using transmission resources in one or more of the N regions, wherein in each region, the reference signal is transmitted using a density determined according to a rule; The method according to any one of items 1 to 8. (Item 10) 10. The method of claim 9, wherein the rules define the use of resource density in each region for the reference signal. (Item 11) Transmitting a reference signal by multiplexing it with a data channel along the frequency domain and / or the time domain. 11. The method according to any one of items 1 to 10, further comprising: (Item 12) transmitting, by the first communication device to the second communication device, an indication message of resources used for data channel transmission and reference signal transmission, whereby: If the data channel falls entirely within a particular region among the N regions, the indication message indicates a resource density of the reference signal transmission for the particular region; or If the data channel occupies two or more of the N regions, the indication message indicates a resource density of the reference signal for the two or more regions; or If a reference signal is not transmitted on the data channel, the indication message indicates the absence of a reference signal transmission. The method according to item 1. (Item 13) Item 13. The method of item 12, wherein, upon determining that estimated interference on a wireless channel between the first communication device and the second communication device is below a threshold, the indication message indicates that there is no reference signal transmission. (Item 14) 14. The method according to items 12-13, wherein in one area, the data channel transmission and reference signal transmission are configured such that resources allocated to reference channel transmission are made unavailable for the data channel transmission. (Item 15) Item 15. The method of item 14, wherein the data channel transmission includes a physical downlink shared channel (PDSCH) transmission or a physical uplink shared channel (PUSCH) transmission. (Item 16) 16. The method according to any one of items 12 to 15, wherein the indication message is carried in downlink control information (DCI). (Item 17) 17. The method according to any one of items 12 to 16, wherein the indication indicates a configuration previously configured by a higher layer message. (Item 18) Item 18. The method of item 17, wherein the higher layer message is a radio resource control (RRC) message that configures the N regions and / or resource densities for the N regions. (Item 19) Item 13. The method of item 12, wherein the indication message and the indication are communicated in a Downlink Control Indicator (DCI) message. (Item 20) Item 10. The method of item 1, wherein the N regions are adjacent to a DMRS transmission in the time domain. (Item 21) Item 10. The method of item 1, wherein the N regions are located in the next symbol after the last DMRS symbol. (Item 22) Item 10. The method of item 1, wherein the N regions are located in previous symbols adjacent to a first DMRS symbol. (Item 23) Item 10. The method of item 1, wherein the resource density corresponds to a density along the time domain. (Item 24) The N regions are comprised of different time densities of a reference signal, and the method comprises: transmitting a reference signal using transmission resources in one or more of the N regions, wherein in each region, the reference signal is transmitted using a density determined according to a rule; Item 24. The method according to item 23. (Item 25) 25. The method of claim 24, wherein the rule specifies that if the reference signal uses transmission resources of a single region among the N regions, the reference signal is transmitted using a time-domain resource density associated with the single region. (Item 26) 25. The method of claim 24, wherein the rule specifies that if the reference signal uses transmission resources of multiple regions of the N regions, the reference signal is transmitted using a time domain resource density associated with each of the multiple regions when the reference signal is transmitted in that region. (Item 27) 25. The method of claim 24, wherein the rule specifies that when the reference signal uses transmission resources of multiple regions of the N regions, the reference signal is transmitted using a time-domain resource density that corresponds to a time-domain resource density of a first region that includes a first symbol used for the transmission of the reference signal. (Item 28) 28. The method according to any one of items 23 to 27, wherein the time density is configured using an index that represents different values ​​in a radio resource control (RRC) message and is indicated by a medium access control control element (MAC CE) or downlink control information (DCI). (Item 29) 29. The method of item 28, wherein one index indicates that no reference signal transmission is performed. (Item 30) 30. The method according to any one of items 1 to 29, wherein the reference signal comprises a pseudo-random sequence or a low peak-to-average power ratio sequence, or the same sequence as a demodulation reference signal or a sounding reference signal or a channel state information reference signal. (Item 31) 30. The method according to any one of items 1 to 29, wherein the reference signal comprises a zero power transmission, in which no signal is transmitted. (Item 32) 1. A method of wireless communication, comprising: receiving, by a second communication device from a first communication device, an indication of N regions within a resource grid defined by transmission resources in the frequency domain and / or time resources in the time domain; each of the N regions has a corresponding resource density indicating a density of time-frequency resources configured for reference signal transmission; N is an integer greater than 1; and communicating the reference signal between the first communication device and the second communication device according to density information; A method comprising: (Item 33) Item 33. The method according to item 32, wherein for each of the N regions, a frequency resource in the frequency domain is configured, and the frequency resource in the frequency domain is defined in units of resource blocks or resource block groups. (Item 34) Item 33. The method of item 32, wherein the density information signals the value of N. (Item 35) 35. The method according to items 33 to 34, wherein if the time resource is not indicated for a particular region, the resource density is interpreted as being applicable to all time units of the particular region. (Item 36) 35. The method according to claim 33, wherein if the time resource is not indicated with respect to a specific region, all time units transmitted by the first communication device or the second communication device are interpreted as being applicable to all time units of the specific region. (Item 37) 35. The method according to items 33 to 34, wherein a time resource in the time domain is configured for each of the N regions, and the time resource is defined for each region in units of transmission symbols or time slots. (Item 38) 38. The method according to any one of items 32 to 37, wherein the resource densities of the N regions are indicated using a scaling factor relative to the resource density of a reference region. (Item 39) 39. The method according to any one of items 32 to 38, wherein the resource density is indicated in a Medium Access Control (MAC) Control Element (CE). (Item 40) receiving a reference signal using transmission resources in one or more of the N regions, wherein in each region, the reference signal is transmitted using a density determined according to a rule; 40. The method according to any one of Items 32 to 39. (Item 41) Item 41. The method according to item 40, wherein the rules define the use of resource density in each region for the reference signal. (Item 42) receiving a reference signal by multiplexing it with a data channel along the frequency domain and / or the time domain; 42. The method according to any one of Items 32 to 41, further comprising: (Item 43) receiving, by the second communication device, from the first communication device, an indication message indicating resources to be used for data channel transmission and reference signal transmission, whereby: If the data channel falls entirely within a particular region among the N regions, the indication message indicates a resource density of the reference signal transmission for the particular region; or If the data channel occupies two or more of the N regions, the indication message indicates a resource density of the reference signal for the two or more regions; or If a reference signal is not transmitted on the data channel, the indication message indicates the absence of a reference signal transmission. Item 33. The method according to item 32. (Item 44) Item 44. The method of item 43, wherein, upon determining that estimated interference on a wireless channel between the first communication device and the second communication device is below a threshold, the indication message indicates that there is no reference signal transmission. (Item 45) 45. The method of claim 43, wherein in one area, the data channel transmission and reference signal transmission are configured such that resources allocated to reference channel transmission are made unavailable for the data channel transmission. (Item 46) Item 46. The method of item 45, wherein the data channel transmission includes a physical downlink shared channel (PDSCH) transmission or a physical uplink shared channel (PUSCH) transmission. (Item 47) 47. The method according to any one of items 43 to 46, wherein the indication message is carried in downlink control information (DCI). (Item 48) 48. The method of any one of items 43 to 47, wherein the indication indicates a configuration previously configured by a higher layer message. (Item 49) Item 49. The method of item 48, wherein the higher layer message is a radio resource control (RRC) message that configures the N regions and / or resource densities for the N regions. (Item 50) Item 44. The method of item 43, wherein the indication message and the indication are communicated in a downlink control indicator (DCI) message. (Item 51) Item 33. The method of item 32, wherein the N regions are adjacent to a DMRS transmission in the time domain. (Item 52) Item 33. The method of item 32, wherein the N regions are located in the next symbol after the last DMRS symbol. (Item 53) Item 33. The method of item 32, wherein the N regions are located in previous symbols adjacent to a first DMRS symbol. (Item 54) 33. The method of claim 32, wherein the resource density corresponds to a density along the time domain. (Item 55) The N regions are comprised of different time densities of a reference signal, and the method comprises: receiving a reference signal using transmission resources in one or more of the N regions, wherein in each region, the reference signal is transmitted using a density determined according to a rule; Item 55. The method according to item 54. (Item 56) Item 56. The method of item 55, wherein the rule specifies that if the reference signal uses transmission resources of a single region among the N regions, the reference signal is transmitted using a time domain resource density associated with the single region. (Item 57) Item 56. The method of item 55, wherein the rule specifies that if the reference signal uses transmission resources of multiple regions of the N regions, the reference signal is transmitted using a time domain resource density associated with each of the multiple regions when the reference signal is transmitted in that region. (Item 58) Item 56. The method of item 55, wherein the rule specifies that when the reference signal uses transmission resources of multiple regions of the N regions, the reference signal is transmitted using a time domain resource density corresponding to a time domain resource density of a first region that includes a first symbol used for the transmission of the reference signal. (Item 59) 59. The method according to any one of items 54 to 58, wherein the time density is configured using an index that represents different values ​​in a radio resource control (RRC) message and is indicated by a medium access control control element (MAC CE) or downlink control information (DCI). (Item 60) Item 59. The method of item 59, wherein one index indicates that no reference signal transmission is performed. (Item 61) Item 61. The method according to any one of items 32 to 60, wherein the reference signal comprises a pseudo-random sequence or a low peak-to-average power ratio sequence, or the same sequence as a demodulation reference signal, a sounding reference signal, or a channel state information reference signal. (Item 62) 61. The method according to any one of items 32 to 60, wherein the reference signal includes a zero power transmission, in which no signal is transmitted. (Item 63) Item 63. The method according to any one of items 1 to 62, wherein the first communication device corresponds to a base station and the second communication device corresponds to a user equipment. (Item 64) Item 63. The method according to any one of items 1 to 62, wherein the first communication device corresponds to a user equipment and the second communication device corresponds to a base station. (Item 65) 65. A wireless communication device comprising a processor configured to implement the method of any one of items 1 to 64. (Item 66) 65. A computer readable medium having stored thereon processor executable code, said code, when executed by said processor, causing said processor to perform the method of any one of items 1 to 64. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 shows an example of a typical frequency spectrum of a wireless signal.

[0010] [Figure 2]FIG. 2 shows an example of a configuration in which downlink to uplink interference may be experienced on the network side.

[0011] [Figure 3] FIG. 3 shows an example of a configuration in which downlink to uplink interference may be experienced on the network side.

[0012] [Figure 4] FIG. 4 illustrates an example configuration in which uplink to downlink interference may be experienced at a wireless device.

[0013] [Figure 5] FIG. 5 illustrates an example configuration in which uplink to downlink interference may be experienced at a wireless device.

[0014] [Figure 6] FIG. 6 shows an example of transmission resources configured for reference signal transmission.

[0015] [Figure 7] FIG. 7 shows an example of transmission resources configured for reference signal transmission.

[0016] [Figure 8] FIG. 8 shows an example of transmission resources configured for reference signal transmission.

[0017] [Figure 9] FIG. 9 shows an example of transmission resources configured for reference signal transmission.

[0018] [Figure 10] FIG. 10 shows an example of transmission resources configured for reference signal transmission.

[0019] [Figure 11A] 11A-11B are flowcharts of exemplary wireless communication methods performed by network devices. [Figure 11B] 11A-11B are flowcharts of exemplary wireless communication methods performed by network devices.

[0020] [Figure 12] FIG. 12 is a block diagram of an example wireless communication device.

[0021] [Figure 13] FIG. 13 illustrates an example of a wireless communication network. DETAILED DESCRIPTION OF THE INVENTION

[0022] Section headings are used in this document solely to improve readability and are not intended to limit the scope of the disclosed embodiments and techniques in each section. Additionally, while some embodiments are described in the context of the 3rd Generation Partnership Project (3GPP®) New Radio (NR) standard ("5G") for ease of understanding, the described techniques may be implemented in different wireless systems implementing protocols other than 5G protocols.

[0023] In existing NR systems, various reference signals, such as Demodulation Reference Signals (DM-RS), Channel State Information Reference Signals (CSI-RS), and Sounding Reference Signals (SRS), are defined to measure interference in wireless communications. A typical reference signal is a signal whose characteristics are predefined so that a receiver of the reference signal knows what to expect. Existing reference signals are typically configured to have the same frequency density across the frequency domain. For example, frequency density may be measured in terms of the number of subcarriers or resource blocks allocated to the reference signal across a unit of frequency.

[0024] However, in scenarios with different interference across the frequency domain, such as subband full duplex and dynamic time division duplex (TDD), configuring reference signals with the same frequency density across the entire frequency bandwidth may cause undesirable resource overhead. For example, in a frequency spectrum with strong or dynamic interference, it may be better to have a high frequency density allocated to reference signal transmission so that that portion of the frequency spectrum can be characterized and calibrated more accurately and quickly. Conversely, in a frequency spectrum region with low and stable interference, it may be more appropriate to have a low frequency density of reference signals to conserve transmission resources for other transmissions, such as data transmission. Similar problems exist in the time domain when interference varies across the time domain. However, current systems fail to recognize such a need and, as a result, do not provide a method by which reference signal transmission with various resource densities, e.g., time or frequency densities, can be configured and used by a wireless communication system.

[0025] This document discloses, among other things, various techniques that may be used by embodiments to configure and use reference signals with different frequency or time resource densities.

[0026] 1. Initial discussions

[0027] In wireless communications, signals must be filtered before transmission over a medium so that the transmitted signal power can be limited within a desired frequency range. Ideally, after filtering, there should be no leakage signals outside the desired frequency range. However, due to limitations in technology and implementation complexity, non-zero signal power, sometimes referred to as leakage signals, typically exists outside the desired frequency range. Figure 1 shows an example of a typical output signal after filtering. In Figure 1, the horizontal axis represents frequency and the vertical axis represents signal power. For a desired signal with a center frequency of f and a bandwidth of B, leakage signals within bandwidth B adjacent to the desired signal (i.e., f-3B / 2 to fB / 2 and f+B / 2 to f+3B / 2) are stronger than leakage signals with bandwidths B further away from the desired signal (e.g., f-5B / 2 to f-3B / 2 and f+3B / 2 to f+5B / 2). Meanwhile, leakage signals within bandwidth B adjacent to the desired signal are more dynamic. The leakage signal acts as interference to the desired signal in the frequency resources f-5B / 2 to fB / 2 and f+B / 2 to f+5B / 2. This is also known as a "roll-off filter."

[0028] To help demodulate the desired signal and ensure optimal operation of the channel between the transmitter and the receiver, the receiver typically measures interference. A reference signal is transmitted to aid in interference measurement. However, reference signal transmission takes bandwidth away from other traffic, such as user data. Therefore, reference signal transmission is typically performed only at a few frequencies and a few time occasions, and channel estimates obtained by receiving reference signals at these times or frequencies are interpolated to obtain channel estimates across the entire frequency band of interest and over the entire period. The receiver can more accurately measure interference and therefore more accurately demodulate the desired signal if the reference signals are transmitted frequently in the time domain or close to each other in the frequency domain. However, transmitting more reference signals results in more resource overhead. To address this situation, the transmitter may transmit more reference signals on frequency resources with strong dynamic interference (e.g., f-3B / 2 to fB / 2 and f+B / 2 to f+3B / 2) and transmit fewer reference signals on frequency resources with low stable interference (e.g., f-5B / 2 to f-3B / 2 and f+3B / 2 to f+5B / 2).

[0029] In some embodiments, available transmission resources may be defined across a grid o in the time and frequency domains, for example, using an Orthogonal Frequency Division Multiple Access (OFDMA) scheme defined by 3GPP for Long Term Evolution or NR technology. In such a system, a transmitter transmits a reference signal to a receiver on one or more resource elements. Each resource element is uniquely identified by an index in the frequency domain and an index in the time domain, where the index in the time domain refers to a symbol position in the time domain relative to some reference point.

[0030] The reference signals have different frequency densities across the frequency domain, and the receiver measures the reference signals to aid in demodulating the desired signal or to monitor interference conditions.

[0031] In various embodiments, the techniques described herein may be implemented in a transmitter-receiver configuration as follows.

[0032] The transmitter is a base station and the receiver is a UE (User Equipment), where the reference signal is used by the UE to demodulate the DL (Downlink) signal.

[0033] The transmitter is the UE and the receiver is the base station, where the reference signal is used by the base station to demodulate the UL (uplink) signal.

[0034] The transmitter is a base station and the receiver is also a base station, in which case the reference signal is used for interference measurement between the base stations.

[0035] The transmitter is a UE and the receiver is also a UE, in which case the reference signal is used for interference measurement between the UEs.

[0036] 2. Examples of different regions with different resource densities

[0037] In a subband full-duplex system, a base station can simultaneously transmit and receive. Figure 2 shows an example of a subband full-duplex system on the base station side. Figure 2 shows an example of a two-dimensional resource grid in which the horizontal axis represents time (in slots) and the vertical axis represents the frequency domain. A similar visual rendering scheme is used with Figures 3 to 6, with additional reference signal resources indicated by diagonal hatching. The area allocated to uplink transmission is indicated by horizontal hatching, and the area allocated to downlink transmission is indicated by vertical hatching. In this example, the bandwidth of the uplink frequency resources in slots 1, 2, and 3 is approximately twice that of the downlink. In slots 1, 2, and 3, there is a guard band between the downlink and uplink resources. The guard band can be several resource blocks (RBs) or even zero RBs. During slots 1, 2, and 3, the base station needs to transmit and receive simultaneously. However, in slot 0, only downlink resources are allocated, so the base station only needs to transmit. Similarly, in slot 4, only uplink resources are allocated, so the base station only needs to receive.

[0038] The transmitted signal has much higher power than the received signal from the base station. Because leakage signals from the transmitted signal enter the received signal, interference from the downlink to the uplink may occur. Due to the "roll-off filter," the interference from the downlink to the uplink may be stronger and more dynamic in the area closer to the downlink resource, i.e., the first area. The interference may also decrease and become flatter in the second area. Therefore, the reference signal in the first area may have a higher frequency density across the frequency domain, and the reference signal in the second area may have a lower frequency density.

[0039] Figure 3 shows another example of a subband full-duplex system on the base station side. Downlink resources are configured on both sides of the uplink resources. In this example, the bandwidth of the uplink frequency resources in slots 1, 2, and 3 is approximately three times the bandwidth of the downlink on each side. Due to the "roll-off filter," interference from the downlink to the uplink may be stronger and more dynamic in areas closer to the downlink resources, i.e., the first and third areas. Also, the interference may decrease and become flatter in the second area. Therefore, the reference signals in the first and third areas may have a higher frequency density across the frequency domain, and the reference signal in the second area may have a lower frequency density.

[0040] Figure 4 shows an example of a subband full-duplex system on the UE side. UE #1 and UE #2 operate on the same carrier, e.g., both at 2.6 GHz with a 60 MHz bandwidth. The UEs operate in half-duplex mode, meaning that they cannot transmit and receive simultaneously. In slots 1, 2, and 3, UE #1 receives the downlink and UE #2 transmits the uplink. Similarly, UE #2's transmit signal has much higher power than UE #1's receive signal. If UE #1 is physically located close to UE #2, interference from the uplink to the downlink may exist due to leakage signals from UE #2's transmit signal entering UE #1's receive signal.

[0041] In this example, the bandwidth of the downlink frequency resource in slots 1 / 2 / 3 is approximately twice that of the uplink. Due to the "roll-off filter," interference from the uplink to the downlink may be stronger and more dynamic in the area closer to the uplink resource, i.e., the first area. The interference may decrease and become flatter in the second area. Therefore, the reference signal in the first area may have a higher frequency density across the frequency domain, and the reference signal in the second area may have a lower frequency density.

[0042] Figure 5 shows another example of a subband full-duplex system on the UE side. The UE can transmit and receive simultaneously in slots 1, 2, and 3. Similarly, the transmit signal has much higher power than the receive signal. Because leakage signals from the transmit signal enter the receive signal, interference from the uplink to the downlink may exist. Due to the "roll-off filter," the uplink to downlink interference may be stronger and more dynamic in the area closer to the uplink resource, i.e., the first area. The interference may decrease and become flatter in the second area. Therefore, the reference signal in the first area may have a higher frequency density across the frequency domain, and the reference signal in the second area may have a lower frequency density.

[0043] Although only a subband full duplex example is described here, reference signals with different frequency densities can be applied to any scenario where the characteristics (e.g., strength and rate of change) of the interference are different across different frequency resources, such as full duplex systems, dynamic TDD systems, TDD systems with different slot formats between cells, and cells with co-channel or adjacent channel interference.

[0044] Although only two or three areas are described here as examples, the number of areas may be more than three. In practice, the number of areas should be determined based on the interference and the implementation algorithm. For example, if the interference characteristics are significantly different among four areas, four areas can be configured.

[0045] The base station configures and indicates to the UE or base station N areas, each area being associated with one frequency density for the reference signal, where N is an integer greater than 1. If the areas are configured for the downlink, the base station transmits the reference signal with the corresponding frequency density associated with each area. If the areas are configured for the uplink, the UE transmits the reference signal with the corresponding frequency density associated with each area.

[0046] Each area may be determined by frequency domain resources (or frequency resources for simplicity) and time domain resources. The frequency domain resources of an area may be determined by one of the following options:

[0047] Option 1. The base station configures frequency resources associated with each area. Each area can have one or more RBs or PRGs (resource block groups).

[0048] Option 2. The base station configures the number of areas. The base station and / or UE determines the frequency resources for each area based on the number of downlink or uplink areas and the total number of RBs / PRGs. For example, if the total number of uplink RBs is 90 RBs and the number of areas is 3, each area contains 30 RBs. If the total number of RBs is not divisible by the number of areas, a specific rule can be used to determine the number of RBs for each area. For example, the first (or last) area can have fewer RBs, and all other areas can have the same number of RBs. If the total number of RBs for the uplink is 86 RBs and the number of areas is 3, the first area and the second area are [ka] the third area has 86-29*2=28 RBs, and the third area has 86-29*2=28 RBs. where: [ka] represents the ceiling function.

[0049] The time domain resources of an area may be determined by one of the following options:

[0050] Option 1. The base station does not configure any time domain resources for each area. In this case, all slots / symbols are associated with each area. For example, if two areas are configured for uplink, all uplink slots / symbols are associated with these two areas.

[0051] Option 2. The base station does not configure any time domain resources for each area. In this case, for a subband full-duplex system, all slots / symbols that the base station or UE can simultaneously transmit and receive are associated with each area. Taking FIG. 2 as an example, if the base station does not configure time domain resources for the first area and the second area, it means that all three slots (slot 1, slot 2, and slot 3) are associated with the first area and the second area. This is because the base station can simultaneously transmit and receive in these three slots.

[0052] Option 3: The base station configures time domain resources for the area. The time domain resources can be configured in units of frames, subframes, slots, subslots, symbols, seconds, or milliseconds. For example, slot 2 is configured as the time domain resource for the first area and the second area.

[0053] The frequency density for the reference signal indicates the density of the reference signal in the frequency domain. The frequency density for each area can be determined by one of the following options:

[0054] Option 1. The base station configures the frequency density associated with each area. Taking FIG. 2 as an example, the base station can configure the frequency density for the first area as "4," meaning that there are four REs transmitting reference signals per RB. The base station can configure the frequency density for the second area as "2," meaning that there are only two REs transmitting reference signals per RB. Here, the densities "4" and "2" are merely example values. The base station can use other values / parameters to indicate the density as long as the base station and the UE can have the same understanding.

[0055] Option 2. The base station configures a frequency density associated with the reference area and configures other scaling factors for other areas. Taking Figure 2 as an example, the base station can configure the frequency density for the first area as "4" and the scaling factor for the second area as "1 / 2". Therefore, the frequency density for the second area can be derived to be "2".

[0056] Option 3. The frequency density for each area is defined herein.

[0057] Option 4. The frequency density for each area is indicated or updated by the MAC-CE.

[0058] Below are some examples of frequency densities: 1. A reference signal is transmitted in each RE of each RB in the area. 2. A reference signal is transmitted in each odd RE (or even RE) of each RB in the area. 3. The reference signal is transmitted in the sixth RE of the odd-numbered RB in the area. 4. A reference signal is transmitted in the second RE and the eighth RE of every six RBs in an area, such as the RB with RB index m and m mod 6=1.

[0059] The transmitter transmits a reference signal with a specific frequency density, and the receiver determines a frequency resource of the reference signal based on the frequency density, and then the receiver can measure the reference signal within the corresponding determined frequency resource.

[0060] If the frequency resource of the reference signal is entirely within one area, the frequency density of the reference is the frequency density associated with this area.

[0061] If the frequency resource of the reference signal spans two or more areas, one of the following options can be applied:

[0062] Option 1: The frequency density of the relevant area is used for the frequency resources of the reference signal in the relevant area. Therefore, there may be multiple frequency densities for one reference signal.

[0063] Option 2. The frequency density of the reference signal is determined by the frequency density associated with the area overlapping with the lowest RB of the reference signal.

[0064] Option 3. The frequency density of the reference signal is determined by the frequency density associated with the area overlapping with the highest RB of the reference signal.

[0065] Option 4. The frequency density of the reference signal is determined by the frequency density associated with the area with the lowest index that overlaps with the reference signal.

[0066] Option 5. The frequency density of the reference signal is determined by the frequency density associated with the area with the highest index that overlaps with the reference signal.

[0067] Option 6. The frequency density of the reference signal is determined by the frequency density associated with the area with the highest frequency that overlaps with the reference signal.

[0068] Option 7. The frequency density of the reference signal is determined by the frequency density associated with the area with the lowest frequency that overlaps with the reference signal.

[0069] Taking Figure 6 as an example, there are a total of eight RBs in the frequency domain, which are divided into two areas: the first area and the second area. Reference signals are transmitted in eight RBs. The frequency density of the first area is higher than that of the second area. In the first area, reference signals are transmitted in odd REs of all four RBs. In the second area, reference signals are transmitted in the first, fifth, and ninth REs of all four RBs.

[0070] Figure 7 shows another example. Similarly, there are a total of eight RBs in the frequency domain, which are divided into two areas, namely, a first area and a second area. A reference signal is transmitted in every RE of all four RBs in the first area. A reference signal is transmitted in every RE of even-numbered RBs in the second area.

[0071] The reference signals may be transmitted along with data channels such as PDSCH and PUSCH, which may be similar to existing DMRS for PDSCH and PUSCH. The resources for the reference signals are not available for the data channels. In other words, when the data channels are subsequently mapped to REs, the data channels are not mapped to those REs used for the reference signals.

[0072] In this case, the reference signal is transmitted within the frequency resources of the data channel. The reference signal is transmitted in one or more symbols of the data channel. If the data channel is transmitted entirely within one area, the frequency density of the reference signal is the frequency density associated with that area. If the data channel is transmitted across two or more areas, the frequency density of the associated area is used for the frequency resources of the reference signal within the associated area. Therefore, there can be multiple frequency densities for one reference signal.

[0073] Taking Figure 8 as an example, there are a total of eight RBs. Each RB has 12 REs. The bottom four RBs are in the first area, and the remaining four RBs are in the second area. The PUSCH is scheduled in the bottom six RBs and transmitted in all 14 symbols in the time domain. The third symbol is used for DMRS transmission, and the fourth symbol transmits a reference signal for interference measurement. Because the PUSCH is transmitted across two areas, the frequency density for the reference signal differs for each area. In the first area, the frequency density is higher, i.e., the reference signal is transmitted in the odd-numbered REs of all four RBs. In the second area, the reference is transmitted in the first, fifth, and ninth REs of the fifth and sixth RBs.

[0074] 3. Example of dynamic indication of frequency density

[0075] Method #1: Dynamic indication of frequency density.

[0076] The base station configures N areas and indicates them to the UE, where N is an integer greater than 1. The DCI indicates the frequency density for the data channel.

[0077] When a data channel is fully transmitted within an area, the DCI indicates the corresponding frequency density for the reference signal transmitted along with the data channel. The frequency density may be transmitted directly by the DCI or may be configured by RRC signaling and indicated by the DCI. The DCI may also indicate that no reference signal is transmitted along with the data channel when interference is low or absent. This may be determined by an interference threshold configured by RRC signaling, such as an RSRP (Reference Signal Received Power) or RSSI (Received Signal Strength Indicator) threshold. If the interference is less than the threshold, no reference signal is required. For example, if RRC configures four frequency densities {4, 2, 1, 0}, "4," "2," or "1" means that there are four REs, two REs, or one RE in each RB for the reference signal, respectively. "0" means that no reference signal is transmitted along with the data channel.

[0078] When a data channel is transmitted across two or more areas, the DCI indicates the corresponding frequency density of the reference signal for each area. RRC signaling configures an association between an index and the corresponding frequency density for each area. The DCI indicates the index, so that the UE can determine the corresponding frequency density for each area.

[0079] Taking Figure 8 as an example, the RRC signaling configures the following association between indexes and corresponding frequency densities for each area: Similarly, "0" means there is no reference signal for the corresponding area. In Figure 8, the DCI indicates index 0 for the UE. Therefore, the UE transmits PUSCH according to the frequency density associated with index 0, i.e., 6 for the first area and 3 for the second area. This is shown in Table 1. [Table 1] Method #2: Dynamic indication of area frequency resources and frequency density.

[0080] The DCI indicates the frequency resources and frequency density of an area for data channels. One of the following options can be used to indicate the frequency resources and frequency density of an area:

[0081] Option 1. RRC signaling configures a first index associated with a frequency resource partition and a second index associated with a frequency density for each area. The DCI indicates the first index and the second index to the UE, so that the UE can determine the frequency density for the corresponding frequency resource. The frequency resource partition for each area is configured according to one of the options of embodiment 2.

[0082] For example, each area may be determined by a frequency domain resource (or frequency resource for simplicity) and a time domain resource. The frequency domain resource of an area may be determined by one of the following options:

[0083] Option 1. The base station configures frequency resources associated with each area. Each area can have one or more RBs or PRGs (resource block groups).

[0084] Option 2. The base station configures the number of areas. The base station and / or UE determines the frequency resource for each area based on the number of downlink or uplink areas and the total number of RBs / PRGs. For example, if the total number of uplink RBs is 90 RBs and the number of areas is 3, each area contains 30 RBs. If the total number of RBs is not divisible by the number of areas, a specific rule can be used to determine the number of RBs for each area. For example, the first (or last) area can have fewer RBs, and all other areas can have the same number of RBs. If the total number of RBs for the uplink is 86 RBs and the number of areas is 3, the first area and the second area can be [ka] the third area has 86-29*2=28 RBs, and the third area has 86-29*2=28 RBs.

[0085] Alternative 2. RRC signaling configures an index associated with a frequency resource partition for each area and corresponding frequency density. The DCI indicates the index to the UE, and the UE can determine the frequency density for the corresponding frequency resource. The frequency resource partition for each area is configured according to one of the alternatives of embodiment 2.

[0086] Taking Figure 8 as an example, the RRC signaling configures an index associated with a frequency resource partition for each area and corresponding frequency density, as shown below. In this example, the DCI indicates index 0 to the UE. Thus, the frequency resource is partitioned into two areas, and the frequency resource for each area can be determined, e.g., each area has the same number of RBs. Table 2 shows an example of resource density in this case. [Table 2]

[0087] Method #3: Another exemplary method

[0088] The following method can also be used to indicate frequency density.

[0089] Method 3-1: DCI indicates the number of frequency densities. If the DCI indicates M as the number of frequency densities, where M is an integer greater than 1, the frequency resources of the scheduled data channel are divided into M areas. For example, if the total number of RBs for scheduled data is 90 RBs and the number of areas is 3, each area includes 30 RBs. If the total number of RBs is not divisible by the number of areas, a specific rule can be used to determine the number of RBs for each area. For example, the first (or last) area can have fewer RBs, and all other areas can have the same number of RBs. If the total number of RBs for the uplink is 86 RBs and the number of areas is 3, the first area and the second area can be divided into M areas. [ka] The first area has 86-29*2=28 RBs, and the third area has 86-29*2=28 RBs. The frequency density per area is configured by RRC signaling or specified in the specifications.

[0090] Method 3-2: DCI indicates the number of frequency densities. If the DCI indicates M frequency densities, where M is an integer greater than 1, the frequency resources of the scheduled data channel are partitioned into M areas.

[0091] 4. Example of a Time Domain Resource

[0092] The reference signal may be transmitted in one or more symbols in the scheduled data channel. The DMRS is used to measure channel conditions. To facilitate PDSCH demodulation, the DMRS symbol or at least some of the DMRS symbols precede the scheduled PDSCH / PUSCH. For Type A PDSCH / PUSCH scheduling, the DMRS is typically in the third or fourth symbol of a slot (counting from the first symbol). For Type B PDSCH / PUSCH scheduling, the DMRS is typically in the first symbol of the scheduled PDSCH / PUSCH.

[0093] The reference signal is used to measure interference and thus helps demodulate the data channel. To facilitate demodulation of the data channel (e.g., obtain interference measurement results faster) and ensure interference measurement accuracy, the reference signal is placed next to the DMRS with the following options:

[0094] Option 1: The reference signal is placed in the symbol following the DMRS. If two consecutive symbols are used as DMRS, the reference signal is placed in the symbol following the last DMRS symbol.

[0095] Option 2: Reference signal is placed in the symbol before the DMRS If two consecutive symbols are used as DMRS, the reference signal is placed in the symbol before the first DMRS symbol.

[0096] The DMRS symbols may also be transmitted in the center or at the edge of the scheduled data channel, depending on the configuration. The reference signal may be configured in the symbol next to or before one or more DMRS symbols.

[0097] Taking FIG. 8 as an example, only one symbol DMRS is transmitted, and the reference signal is transmitted in the symbol following the DMRS.

[0098] Taking Figure 9 as an example, a total of four symbols are transmitted, divided into two sets. The first set of DMRS symbols is at the beginning and occupies two consecutive symbols. The second set of DMRS symbols is at the end and also occupies two consecutive symbols. In this example, the reference signal is transmitted in the symbol following the last DMRS symbol in each set of DMRS symbols.

[0099] 5. Example of a sequence transmitted via a reference signal

[0100] The transmitter does not transmit any signal on these resources for the reference signal, which the receiver can then use to measure the interference situation.

[0101] Alternatively, the transmitter may transmit the following sequence over these resources for the reference signal:

[0102] Option 1. Pseudorandom sequence;

[0103] Option 2. Low PAPR (Peak-to-Average Power) sequences, e.g., Zadoff-Chu sequences;

[0104] Option 3. Sequence reuse for DMRS;

[0105] Option 4. Reuse of sequences for SRS;

[0106] Option 5. Sequence reuse for CSI-RS.

[0107] 6. Examples of different time densities with respect to the reference signal

[0108] Interference may also vary between different symbols / slots. Taking Figure 2 as an example, there is downlink-to-uplink interference at the base station side and uplink-to-downlink interference at the UE side, so the interference in slot 0 or slot 4 is lower than that in slot 1, slot 2, or slot 3. Therefore, the reference signal also has different time density in the time domain. For example, in slot 0 and slot 4, the reference signal is transmitted with two symbols in each slot. In slot 1, slot 2, and slot 3, the reference signal is transmitted with four symbols in each slot.

[0109] Different methods can be applied to configure or indicate different time densities for the reference signal.

[0110] Method #1: The base station configures different time domains and time densities associated with the time domains.

[0111] The time domain may encompass one or more symbols / slots and may be defined as a time-domain pattern. For example, in Figure 10, a first time-domain pattern may be slot 0 and slot 4 in each period, and the period is 5 slots. A second time-domain pattern may be slot 1, slot 2, and slot 3 in each period.

[0112] When the reference signal is transmitted in one time domain, the time density of the reference signal is determined by the time domain in which the reference signal is transmitted.

[0113] If the reference signal is transmitted over more than one time domain, the time density of the reference signal is determined by the following options:

[0114] Option 1. The time density of the reference signal is determined by the time domain over which the reference signal is transmitted.

[0115] Option 2. The time density of the reference signal is determined by the time region that overlaps with the first symbol of the reference signal.

[0116] Option 3. The time density of the reference signal is determined by the time region that overlaps with the last symbol of the reference signal.

[0117] Method #2: The base station indicates the time density for the reference signal via DCI or MAC-CE.

[0118] The RRC signaling comprises a set of configurations including an index to the UE and a corresponding time density associated with the index. The DCI or MAC-CE indicates the index to the UE. The UE determines the time density of the reference signal based on the indication. One of the indices indicates that the reference signal is not transmitted.

[0119] For example, RRC signaling may configure the following association to a UE: Index 0 refers to time density "4", meaning that the reference signal is transmitted with four symbols in each slot. There are many general solutions for determining which four symbols are used, e.g., the RRC signaling, the symbols formed by the first and second symbols of the scheduled data channel plus the last and second-last symbols. Index 3 refers to time density 0, meaning that no reference signal is transmitted. Table 3 shows an example of such a configuration. [Table 3]

[0120] The DCI or MAC-CE may also indicate more than one time densities to the UE. If the DCI schedules the PDSCH / PUSCH with N-1 repetitions (thus, a total of N PDSCH / PUSCH transmissions), or if the DCI schedules N PDSCH / PUSCH transmissions in different transport blocks, the DCI indicates M time densities for the PDSCH / PUSCH via the following options: N is an integer greater than 1; M is an integer greater than 1 and M is less than or equal to N; Typically, M is equal to 2.

[0121] Option 1. First [ka] The reference signal transmitted along with the PDSCH / PUSCH transmission is transmitted at the first time density indicated by the DCI. [ka] The reference signal transmitted along with the PDSCH / PUSCH transmission is transmitted at a second time density indicated by the DCI, and so on.

[0122] Option 2. The reference signal transmitted along with the ((i mod M)+1)-th PDSCH / PUSCH is transmitted at the ((i mod M)+1)-th time density indicated by the DCI, where i is the PDSCH / PUSCH index starting from 0. For example, if the DCI schedules four PDSCH transmissions and indicates two time densities, the time density for the reference signal transmitted along with the first PDSCH (i.e., the PDSCH with index 0) is the first time density indicated by the DCI. Similarly, the time density for the reference signal transmitted along with the third PDSCH (i.e., the PDSCH with index 2) is the first time density indicated by the DCI. The time density for the reference signal transmitted along with the second PDSCH (i.e., the PDSCH with index 1) is the second time density indicated by the DCI. The time density for the reference signal transmitted along with the fourth PDSCH (i.e., the PDSCH with index 3) is the second time density indicated by the DCI.

[0123] 7. Examples of different frequency densities for DMRS

[0124] Interference may be dynamic across the time domain. Taking Figure 2 as an example, in slots 0 and 4, interference may be small compared to interference in slots 1, 2, and 3. Therefore, two DMRSs may be defined. The first DMRS involves one frequency density, and the second DMRS involves another frequency density. The DCI indicates the frequency density of the transmitted DMRS for the scheduled data channel.

[0125] In summary, M sets of DMRSs can be defined, with each set of DMRSs associated with one frequency density. The DCI indicates one of the M sets of DMRSs for the scheduled data channel. In other words, the DCI indicates one of the M frequency densities of the DMRS transmitted for the scheduled data channel.

[0126] For example, in this embodiment, the base station does not need to configure or indicate any area, but only indicates the corresponding frequency density to the receiver.

[0127] 8. Example of a reference signal transmitted overlapping with a guard interval

[0128] For a sub-band full-duplex system, one or more symbols are reserved for transitioning communication directions. Taking Figure 10 as an example, in slot 1, the third and fourth symbols are reserved as guard periods (GPs) for transitioning from downlink to uplink. Similarly, in slot 3, the eleventh and twelfth symbols are reserved as guard periods.

[0129] It should be noted that the reference signal here is not limited to a reference signal with a different frequency density, it can be any reference signal.

[0130] The base station and the UE do not transmit any signals during the guard period. Therefore, in a subband full-duplex system, a reference signal can be transmitted using DL symbols overlapping with the guard period and UL symbols overlapping with the guard period. Because the base station and the UE do not transmit any signals during the guard period, the reference signal transmitted in the DL symbols (or UL symbols) overlapping with the guard period can be protected with less interference.

[0131] The reference signal transmitted in the DL symbol that overlaps the guard period can be either:

[0132] Option 1. DMRS. If a UE receives DMRS in a DL symbol that overlaps with a guard period, there are no other UEs transmitting uplink.

[0133] Option 2. CSI-RS. When the UE or another base station receives the DMRS in a DL symbol that overlaps with the guard period, there are no other UEs transmitting uplink.

[0134] The reference signal transmitted in the UL symbol that overlaps the guard period can be either:

[0135] Option 1. DMRS. If a base station receives DMRS in an UL symbol that overlaps with a guard period, there is no interference from its own downlink.

[0136] Option 2. SRS. If the base station receives the SRS in a UL symbol that overlaps with the guard period, there is no interference from its own downlink.

[0137] The guard period can be configured as a flexible symbol, so that the base station and the UE do not transmit any signals on the guard period.

[0138] Some preferred embodiments may incorporate the following solution features:

[0139] Referring to Sections 1-6, some exemplary solutions implemented on the transmitter side may be as follows:

[0140] 1. A method of wireless communication (e.g., method 1100 depicted in FIG. 11A ) comprising: transmitting 1102 from a first communication device to a second communication device an indication of N regions within a resource grid defined by transmission resources in the frequency domain and / or time resources in the time domain, where each of the N regions has a corresponding resource density indicating a density of time-frequency resources configured for reference signal transmission, where N is an integer greater than 1; and communicating 1104 a reference signal between the first communication device and the second communication device in accordance with the density information. Various configurations and examples of regions (also referred to as “areas”) are described with reference to FIGS.

[0141] Referring to Section 2, some example solutions may be as follows:

[0142] 2. The method of Solution 1, further comprising configuring frequency resources in the frequency domain for each of the N regions, the frequency resources in the frequency domain being defined in units of resource blocks or resource block groups.

[0143] 3. The method of solution 1, where density information signals the value of N.

[0144] 4. Solutions 2-3, where if time resources are not indicated for a particular area, the resource density is interpreted as applicable to all time units in the particular area.

[0145] 5. The method of solutions 2 to 3, wherein if the time resource is not indicated with respect to a specific region, all time units transmitted by the first communication device or the second communication device are interpreted as being applicable to all time units of the specific region.

[0146] 6. The method of solutions 2-3, further comprising configuring time resources in the time domain for each of the N regions, the time resources being defined for each region in units of transmission symbols or time slots.

[0147] 7.Any of Solutions 1-6, where the resource density of N regions is indicated using a scaling factor with respect to the resource density of the reference region.

[0148] 8. The method of any of solutions 1 to 7, wherein resource density is indicated in a medium access control (MAC) control element (CE).

[0149] 9. The method of any of solutions 1 to 8, further comprising transmitting a reference signal using transmission resources in one or more of the N regions, wherein in each region, the reference signal is transmitted using a density determined according to a rule.

[0150] 10. The method of solution 9, wherein the rules stipulate that the resource density of each region is used for the reference signal.

[0151] 11. The method of any of solutions 1 to 10, further comprising transmitting the reference signal by multiplexing it with the data channel along the frequency domain and / or the time domain.

[0152] Referring to Section 3, some example solutions may be as follows:

[0153] 12. The method of Solution 1, including transmitting an indication message by the first communication device to the second communication device indicating resources used for data channel transmission and reference signal transmission, whereby if the data channel falls entirely within a particular region of the N regions, the indication message indicates the resource density of reference signal transmission for the particular region, or if the data channel occupies two or more regions of the N regions, the indication message indicates the resource density of reference signals for two or more regions, or if a reference signal is not transmitted on the data channel, the indication message indicates no reference signal transmission.

[0154] 13. The method of solution 12, wherein, upon determining that the estimated interference on the wireless channel between the first communication device and the second communication device is below a threshold, the indication message indicates that there is no reference signal transmission. The threshold may be a predefined number or may be implementation specific.

[0155] 14. The method of solutions 12-13, wherein in one area, the data channel transmission and the reference signal transmission are configured such that resources allocated to the reference channel transmission are made unavailable for the data channel transmission.

[0156] 15. The method of solution 14, wherein the data channel transmission comprises a physical downlink shared channel (PDSCH) transmission or a physical uplink shared channel (PUSCH) transmission.

[0157] 16. The method of solutions 12-15, wherein the indication message is carried in downlink control information (DCI).

[0158] 17. The method of solutions 12-16, wherein the indication indicates a configuration previously configured by a higher layer message.

[0159] 18. The method of solution 17, wherein the higher layer message is a radio resource control (RRC) message that configures the N regions and / or resource density for the N regions.

[0160] 19. The method of solution 12, wherein the indication message and the indication are communicated in a Downlink Control Indicator (DCI) message.

[0161] Referring to Section 4, some example solutions may be as follows:

[0162] 20. The method of Solution 1, wherein N regions are adjacent to the DMRS transmission in the time domain.

[0163] 21. The method of Solution 1, wherein the N regions are placed in the next symbol after the last DMRS symbol.

[0164] 22. The method of Solution 1, wherein the N regions are located in a previous symbol adjacent to the first DMRS symbol.

[0165] Referring to Section 6, some example solutions may be as follows:

[0166] 23. Solution 1 method, where resource density corresponds to density along the time domain.

[0167] 24. The method of Solution 23, wherein the N regions are configured with different time densities of the reference signal, and the method further comprises transmitting the reference signal using transmission resources in one or more of the N regions, wherein in each region the reference signal is transmitted using a density determined according to a rule.

[0168] 25. The method of solution 24, wherein the rule provides that if the reference signal uses the transmission resources of a single region of the N regions, the reference signal is transmitted using the time domain resource density associated with the single region.

[0169] 26. The method of Solution 24, wherein the rule provides that if a reference signal uses transmission resources of multiple regions of N regions, the reference signal is transmitted using the time domain resource density associated with each of the multiple regions when the reference signal is transmitted in that region.

[0170] 27. The method of solution 24, wherein the rule specifies that when the reference signal uses transmission resources of multiple regions of N regions, the reference signal is transmitted using a time-domain resource density that corresponds to the time-domain resource density of a first region that encompasses a first symbol used for transmission of the reference signal.

[0171] 28. The method of any of Solutions 23 to 27, wherein the time density is configured using an index that represents different values ​​in a radio resource control (RRC) message and is indicated by a medium access control control element (MAC CE) or downlink control information (DCI).

[0172] 29. The method of solution 28, wherein one index indicates that no reference signal transmission is performed.

[0173] 30. The method of any of Solutions 1 to 29, wherein the reference signal comprises a pseudorandom sequence or a low peak-to-average power ratio sequence, or the same sequence as the demodulation reference signal, the sounding reference signal, or the channel state information reference signal.

[0174] 31. The method of any of Solutions 1 to 29, wherein the reference signal includes a zero-power transmission, where no signal is transmitted.

[0175] Referring to Sections 1-6, some exemplary solutions implemented at the receiver side may be as follows:

[0176] 32. A method of wireless communication (e.g., method 1150 depicted in FIG. 11B ) including receiving, by a second communication device from a first communication device, an indication of N regions within a resource grid defined by transmission resources in the frequency domain and / or time resources in the time domain (1152), where each of the N regions has a corresponding resource density indicating a density of time-frequency resources configured for reference signal transmission, where N is an integer greater than 1; and communicating a reference signal between the first communication device and the second communication device (1154) in accordance with the density information. Various configurations and examples of regions (also referred to as "areas") are described with reference to FIGS. 2-10.

[0177] Referring to Section 2, some example solutions may be as follows:

[0178] 33. The method of solution 32, wherein for each of the N regions, frequency resources in the frequency domain are configured, and the frequency resources in the frequency domain are defined in units of resource blocks or resource block groups.

[0179] 34. A method of solution 32 in which density information signals the value of N.

[0180] 35. The method of solutions 33-34, in which if time resources are not indicated for a particular area, the resource density is interpreted as applicable to all time units in the particular area.

[0181] 36. The method of solutions 33-34, wherein if the time resource is not indicated with respect to a specific region, all time units transmitted by the first communication device or the second communication device are interpreted as being applicable to all time units of the specific region.

[0182] 37. The method of solutions 33-34, wherein for each of the N regions, a time resource in the time domain is configured, and the time resource is defined for each region in units of transmission symbols or time slots.

[0183] 38.Any of Solutions 32-37, in which the resource density of N regions is indicated using a scaling factor with respect to the resource density of a reference region.

[0184] 39. The method of any of solutions 32-38, wherein resource density is indicated in a medium access control (MAC) control element (CE).

[0185] 40. The method of any of solutions 32 to 39, further comprising receiving a reference signal using transmission resources in one or more of the N regions, wherein in each region the reference signal is transmitted using a density determined according to a rule.

[0186] 41. The method of solution 40, wherein the rules stipulate that the resource density of each region is used for the reference signal.

[0187] 42. The method of any of solutions 32-41, further comprising receiving a reference signal by multiplexing it with the data channel along the frequency domain and / or the time domain.

[0188] Referring to Section 3, some example solutions may be as follows:

[0189] 43. The method of Solution 32, including receiving, by a second communication device, an indication message from the first communication device indicating resources used for data channel transmission and reference signal transmission, whereby if the data channel falls entirely within a particular region of the N regions, the indication message indicates a resource density of reference signal transmission for the particular region, or if the data channel occupies two or more regions of the N regions, the indication message indicates a resource density of reference signals for two or more regions, or if a reference signal is not transmitted on the data channel, the indication message indicates no reference signal transmission.

[0190] 44. The method of solution 43, wherein upon determining that the estimated interference on the wireless channel between the first communication device and the second communication device is below a threshold, the indication message indicates that there is no reference signal transmission. The threshold may be a predefined number or may be implementation specific.

[0191] 45. The method of solutions 43-44, wherein in one area, the data channel transmission and the reference signal transmission are configured such that resources allocated to the reference channel transmission are made unavailable for the data channel transmission.

[0192] 46. ​​The method of solution 45, wherein the data channel transmission includes a physical downlink shared channel (PDSCH) transmission or a physical uplink shared channel (PUSCH) transmission.

[0193] 47. The method of solutions 43-46, wherein the indication message is carried in downlink control information (DCI).

[0194] 48. The method of solutions 43-47, wherein the indication indicates a configuration previously configured by an upper layer message.

[0195] 49. The method of solution 48, wherein the higher layer message is a radio resource control (RRC) message that configures the N regions and / or resource density for the N regions.

[0196] 50. The method of solution 43, wherein the indication message and the indication are communicated in a Downlink Control Indicator (DCI) message.

[0197] Referring to Section 4, some example solutions may be as follows:

[0198] 51. The method of Solution 32, wherein the N regions are adjacent to the DMRS transmission in the time domain.

[0199] 52. The method of Solution 32, wherein the N regions are placed in the next symbol after the last DMRS symbol.

[0200] 53. The method of Solution 32, wherein the N regions are located in a previous symbol adjacent to the first DMRS symbol.

[0201] Referring to Section 6, some example solutions may be as follows:

[0202] 54. Solution 32 method, where resource density corresponds to density along the time domain.

[0203] 55. The method of Solution 54, wherein the N regions are configured with different time densities of the reference signal, and the method further comprises receiving the reference signal using transmission resources in one or more of the N regions, and in each region, the reference signal is transmitted using a density determined according to a rule.

[0204] 56. The method of solution 55, wherein the rule provides that if the reference signal uses the transmission resources of a single region of the N regions, the reference signal is transmitted using the time domain resource density associated with the single region.

[0205] 57. The method of Solution 55, wherein the rule provides that if a reference signal uses transmission resources of multiple regions of N regions, the reference signal is transmitted using the time domain resource density associated with each of the multiple regions when the reference signal is transmitted in that region.

[0206] 58. The method of solution 55, wherein the rule specifies that when the reference signal uses transmission resources of multiple regions of N regions, the reference signal is transmitted using a time-domain resource density that corresponds to the time-domain resource density of a first region that encompasses a first symbol used for transmission of the reference signal.

[0207] 59. The method of any of solutions 54-58, wherein the time density is configured using an index that represents different values ​​in a radio resource control (RRC) message and is indicated by a medium access control control element (MAC CE) or downlink control information (DCI).

[0208] 60. The method of solution 59, wherein one index indicates that no reference signal transmission is performed.

[0209] 61. The method of any of Solutions 32 to 60, wherein the reference signal comprises a pseudorandom sequence or a low peak-to-average power ratio sequence, or the same sequence as the demodulation reference signal, the sounding reference signal, or the channel state information reference signal.

[0210] 62. The method of any of Solutions 32-60, wherein the reference signal includes a zero-power transmission where no signal is transmitted.

[0211] The above solution may preferably be implemented as follows.

[0212] 63. The method of any of solutions 1 to 62, wherein the first communication device corresponds to a base station and the second communication device corresponds to user equipment.

[0213] 64. The method of any of solutions 1 to 62, wherein the first communication device corresponds to a user equipment and the second communication device corresponds to a base station.

[0214] 65. A wireless communication device comprising a processor configured to implement a method according to any one of solutions 1 to 64.

[0215] 66. A computer-readable medium having stored thereon processor-executable code, the code, when executed by a processor, causing the processor to perform a method according to any one of solutions 1 to 64.

[0216] 12 is a block diagram of an exemplary implementation of a wireless communication device 1200. Methods 1100 and 1150 may be performed by device 1200. In some embodiments, for example, when performing method 1100, device 1200 may be a first communication device, such as a base station or network device of a wireless network, and the second communication device may be a UE. In some embodiments, for example, when performing method 1150, device 1200 may be a second communication device, such as a UE. Apparatus 1200 includes one or more processors, e.g., processor electronics 1210, transceiver circuitry 1215, and one or more antennas 1220, for transmission and reception of wireless signals. Apparatus 1200 may include memory 1205, which may be used to store data and instructions used by processor electronics 1210. Apparatus 1200 may also include additional network interfaces to additional equipment of one or more core networks or network operators. This additional network interface, not explicitly shown in FIG. 12, may be wired (eg, fiber or Ethernet) or wireless.

[0217] 13 illustrates an example of a wireless communication system 1300 in which various technologies described herein may be implemented. The system 1300 includes a base station 1302 that may have a communication connection with a core network (1312) and a wireless communication medium 1304 for communicating with one or more user devices 1306. The user devices 1306 may be smartphones, tablets, machine-to-machine communication devices, Internet of Things (IoT) devices, etc.

[0218] It can be understood that techniques for achieving different reference signal resource densities in the time and / or frequency domains can be implemented. In one advantageous aspect, the disclosed techniques can be used by a transmitter (e.g., a base station) to schedule a denser resource grid for reference signals in time-frequency regions where the potential for interference is higher, e.g., in time-frequency regions where uplink and downlink transmissions occupy adjacent or nearby time slots of subcarriers. Those skilled in the art can further understand that the disclosed techniques can be used to reserve specific resource elements as zero-power transmission resources (e.g., reference signal transmissions that do not include signal transmissions). Furthermore, embodiments may be able to divide all available time-frequency resources into multiple regions (also referred to herein as areas), and resource densities may be defined for each region. Data and reference signal transmissions may fall entirely within a single region or occupy multiple regions, thereby providing flexible resource density organization.

[0219] The disclosed and other embodiments, modules, and functional operations described in this document may be implemented in digital electronic circuitry, or in computer software, firmware, or hardware, including the structures disclosed herein and their structural equivalents, or in one or more combinations thereof. The disclosed and other embodiments may be implemented as one or more computer program products, i.e., one or more modules of computer program instructions encoded on a computer-readable medium for execution by or controlling the operation of a data processing apparatus. The computer-readable medium may be a machine-readable storage device, a machine-readable storage substrate, a memory device, a composition of matter providing a machine-readable propagated signal, or one or more combinations thereof. The term "data processing apparatus" encompasses all apparatuses, devices, and machines for processing data, including, by way of example, a programmable processor, a computer, or multiple processors or computers. In addition to hardware, an apparatus may include code that creates an execution environment for the computer program in question, such as code constituting processor firmware, a protocol stack, a database management system, an operating system, or one or more combinations thereof. A propagated signal is an artificially generated signal, such as a mechanically generated electrical, optical, or electromagnetic signal, that is generated to encode information for transmission to an appropriate receiving device.

[0220] A computer program (also known as a program, software, software application, script, or code) can be written in any form of programming language, including compiled or interpreted languages, and can be deployed in any form, including as a stand-alone program or as modules, components, subroutines, or other units suitable for use in a computing environment. A computer program does not necessarily correspond to a file in a file system. A program can be stored as part of a file that holds other programs or data (e.g., one or more scripts stored in a markup language document), in a single file dedicated to the program in question, or in multiple cooperating files (e.g., files that store one or more modules, subprograms, or portions of code). A computer program can be deployed to be executed on one computer, on multiple computers located at one site, or on multiple computers distributed across multiple sites and interconnected by a communications network.

[0221] The processes and logic flows described in this document may be performed by one or more programmable processors executing one or more computer programs to perform functions by manipulating input data and generating output. The processes and logic flows may also be performed by, or an apparatus may be implemented as, special purpose logic circuitry, such as an FPGA (Field Programmable Gate Array) or an ASIC (Application Specific Integrated Circuit).

[0222] Processors suitable for executing a computer program include, by way of example, both general-purpose and special-purpose microprocessors, and any one or more processors of any kind of digital computer. Typically, a processor receives instructions and data from a read-only memory or a random-access memory, or both. The essential elements of a computer are a processor for executing instructions and one or more memory devices for storing instructions and data. Typically, a computer also includes one or more mass storage devices for storing data, such as magnetic, magneto-optical, or optical disks, or is operatively coupled to receive data from or transfer data to them, or both. However, a computer need not have such devices. Computer-readable media suitable for storing computer program instructions and data include, by way of example, semiconductor memory devices such as EPROMs, EEPROMs, and flash memory devices; magnetic disks, such as internal or removable disks; magneto-optical disks; and all forms of non-volatile memory, media, and memory devices, including, by way of example, CD-ROM and DVD-ROM disks. The processor and memory can be supplemented by, or incorporated in, special-purpose logic circuitry.

[0223] While this document contains many details, these should not be construed as limitations on the scope of the claimed invention or the inventions that may be claimed, but rather as descriptions of features specific to particular embodiments. Certain features described in this document in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment may also be implemented in multiple embodiments separately or in any suitable subcombination. Furthermore, while features may be described above as acting in a particular combination and initially claimed as such, one or more features from a claimed combination may, in some cases, be cut from the combination, and the claimed combination may be directed to a subcombination or a variation of the subcombination. Similarly, although operations are depicted in the figures in a particular order, this should not be understood as requiring such operations to be performed in the particular order shown, or in the sequential order shown, or that all of the operations shown be performed, to achieve desirable results.

[0224] Only a few examples and embodiments are disclosed. Variations, modifications, and enhancements to the examples and embodiments described, as well as other embodiments, can be made based on what is disclosed.

Claims

1. 1. A method of wireless communication, comprising: transmitting, by a first communication device to a second communication device, an indication of N regions within a resource grid defined by transmission resources in the frequency domain and / or time resources in the time domain, each of the N regions has a corresponding resource density indicating a density of time-frequency resources configured for reference signal transmission; N is an integer greater than 1; and communicating with the second communication device by the first communication device using a reference signal according to the corresponding resource density; transmitting, by the first communication device to the second communication device, an indication message indicating resources used for data channel transmission and reference signal transmission; If the data channel falls entirely within a specific region among the N regions, the indication message indicates a resource density of reference signal transmission for the specific region; and If the data channel occupies two or more regions among the N regions, the indication message indicates a resource density of reference signal transmission for the two or more regions; If a reference signal is not transmitted on the data channel, the indication message indicates the absence of reference signal transmission. It has become like this, A method comprising:

2. further comprising configuring frequency resources in the frequency domain for each of the N regions; The frequency resource in the frequency domain is defined in units of resource blocks or resource block groups. The method of claim 1.

3. The method of claim 2 , wherein if the time resource is not indicated for a particular region, the resource density corresponds to all time units of the particular region.

4. and further comprising: configuring, by the first communication device, time resources in the time domain for each of the N regions, the time resources being defined for each region in units of transmission symbols or time slots. The method of claim 2.

5. The method of claim 1 , wherein the resource densities of the N regions are indicated using a scaling factor relative to the resource density of a reference region.

6. 1. A method of wireless communication, comprising: receiving, by a second communication device from a first communication device, an indication of N regions within a resource grid defined by transmission resources in the frequency domain and / or time resources in the time domain, each of the N regions has a corresponding resource density indicating a density of time-frequency resources configured for reference signal transmission; N is an integer greater than 1; and communicating with the first communication device by the second communication device using a reference signal according to the corresponding resource density; receiving, by the second communication device, from the first communication device, an indication message indicating resources to be used for data channel transmission and reference signal transmission; If the data channel falls entirely within a specific region among the N regions, the indication message indicates a resource density of reference signal transmission for the specific region; and If the data channel occupies two or more regions among the N regions, the indication message indicates a resource density of reference signal transmission for the two or more regions; If a reference signal is not transmitted on the data channel, the indication message indicates the absence of reference signal transmission. It has become like this, A method comprising:

7. 7. The method of claim 6, further comprising: configuring, for each of the N regions, frequency resources in the frequency domain, wherein the frequency resources in the frequency domain are defined in units of resource blocks or resource block groups.

8. The method of claim 7 , wherein if the time resource is not indicated for a particular region, the resource density corresponds to all time units of the particular region.

9. 8. The method of claim 7, further comprising: configuring time resources in the time domain for each of the N regions, the time resources being defined for each region in units of transmission symbols or time slots.

10. The method of claim 6 , wherein the resource densities of the N regions are indicated using a scaling factor relative to the resource density of a reference region.

11. The method according to any one of claims 1 to 10, wherein the first communication device corresponds to a base station and the second communication device corresponds to a user equipment.

12. The method according to any one of claims 1 to 10, wherein the first communication device corresponds to a user equipment and the second communication device corresponds to a base station.

13. A wireless communication device comprising a processor configured to perform the method of any one of claims 1 to 10.

Images