Communication techniques based on adaptive numerology
11101954 · 2021-08-24
Assignee
Inventors
- Ali Ramadan (Munich, DE)
- Karthikeyan Ganesan (Munich, DE)
- Malte Schellmann (Munich, DE)
- Mohamed Gharba (Munich, DE)
- Tapisha Soni (Munich, DE)
Cpc classification
H04L27/2695
ELECTRICITY
H04L27/26025
ELECTRICITY
H04L27/26134
ELECTRICITY
H04L5/0048
ELECTRICITY
International classification
Abstract
A mobile communication device has a receiver configured to receive a radio signal over a radio channel. The radio signal has a predetermined pilot preamble. The mobile communication device has a processor configured to determine mobility information, in particular a Doppler and/or a Delay Spread, based on the pilot preamble. The processor is further configured to signal the mobility information to a second communication device. A base station is also provided, having: a receiver configured to receive mobility information, in particular a Doppler and/or a Delay Spread, signaled by a mobile communication device; and a processor, configured to select a numerology based on the mobility information and to generate a radio signal for transmission to the communication device based on the numerology.
Claims
1. A mobile communication device comprising: a receiver configured to receive a radio signal over a radio channel, the radio signal comprising a predetermined pilot preamble; and a processor configured to determine mobility information based on the pilot preamble, the mobility information comprising a Doppler spread and/or a delay spread, wherein the processor is further configured to signal the mobility information to a second communication device, and wherein the mobility information comprises the Doppler spread and the delay spread, wherein the Doppler spread and/or the delay spread are based on outer loop processing, and wherein the outer loop processing is configured to be performed at a lower rate than a rate used for link adaptation between the mobile communication device and the second communication device.
2. The mobile communication device of claim 1, wherein the processor is configured to determine a pilot of a first type of pilots, which is configured to be used for channel estimation, and a pilot of a second type of pilots, wherein the pilot of the second type of pilots is configured to be used for the determination of the mobility information.
3. The mobile communication device of claim 2, wherein the first type of pilots are periodic with a radio subframe and the second type of pilots are periodic with at least multiples of a radioframe of multiple subframes.
4. The mobile communication device of claim 1, wherein the processor is configured to signal the mobility information to the second communication device that comprises: a base station in a cellular vehicle-to-anything scenario; or a mobile communication device in a vehicle-to-vehicle scenario for a sidelink.
5. A base station comprising: a receiver configured to receive mobility information signaled by a mobile communication device, the mobility information comprising a Doppler spread and/or a delay spread; and a processor configured to: select a numerology based on the mobility information and to generate a radio signal for transmission to the mobile communication device based on the numerology, and wherein the selecting the numerology based on the mobility information comprises selecting the numerology based on the mobility information and a quality-of-service requirement.
6. The base station of claim 5, wherein the numerology is based on at least one of the following parameters based on the mobility information: a subcarrier spacing, a length of cyclic prefix, a pilot distribution, or a transmission time interval.
7. The base station of claim 5, wherein the processor is configured: to select a numerology for a sidelink communication of the mobile communication device based on mobility information received for the sidelink, and to select a numerology for a central communication link of the mobile communication device with the base station based on mobility information received for the central communication link.
8. The base station of claim 5, wherein the processor is configured to perform an outer loop processing comprising the numerology selection and/or a numerology configuration, and wherein the outer loop processing is performed at a lower rate than a rate used for link adaptation between the base station and the mobile communication device.
9. The base station of claim 8, wherein the processor is configured to re-configure a radio bearer to different time-frequency resources having a numerology based on the mobility information.
10. The base station of claim 5, comprising a shared hybrid automatic repeat request (HARQ) entity across different numerologies, wherein the processor is configured to trigger each HARQ redundancy versions based on the mobility information to a different numerology of the different numerologies.
11. The base station of claim 5, wherein the processor is configured to select the numerology for at least one component carrier transmitting the radio signal.
12. The base station of claim 5, wherein the processor is configured to insert a predetermined pilot preamble into the radio signal, wherein the pilot preamble is configured to determine channel conditions, in particular the Doppler spread and/or the delay spread.
13. A mobility information sending method for a communication device, the method comprising: receiving a radio signal over a radio channel, the radio signal comprising a predetermined pilot preamble; determining mobility information based on the pilot preamble, the mobility information comprising a Doppler spread and/or a delay spread; and sending the mobility information to a second communication device, and wherein the mobility information comprises the Doppler spread and the delay spread, wherein the Doppler spread and/or the delay spread are provided based on outer loop processing, and wherein the outer loop processing is performed at a lower rate than a rate used for link adaptation between the communication device and the second communication device.
14. The method of claim 13, the method further comprising determining a pilot of a first type of pilots, which is used for channel estimation, and a pilot of a second type of pilots for the determination of the mobility information.
15. The method of claim 14, wherein the first type of pilots are periodic with a radio subframe and the second type of pilots are periodic with at least multiples of a radioframe of multiple subframes.
16. The method of claim 13, wherein the second communication device comprises: a base station in a cellular vehicle-to-anything scenario; or a mobile communication device in a vehicle-to-vehicle scenario for a sidelink.
17. A mobility information receiving method for a base station, the method comprising: receiving mobility information signaled by a mobile communication device, the mobility information comprising a Doppler spread and/or a delay spread; selecting a numerology based on the mobility information; and generating a radio signal for transmission to the mobile communication device based on the numerology, and wherein the selecting the numerology based on the mobility information comprises selecting the numerology based on the mobility information and a quality-of-service requirement.
18. The method of claim 17, wherein the numerology is based on at least one of the following parameters based on the mobility information: a subcarrier spacing, a length of cyclic prefix, a pilot distribution, or a transmission time interval.
19. The method of claim 17, the method further comprising: selecting a numerology for a sidelink communication of the mobile communication device based on mobility information received for the sidelink; and selecting a numerology for a central communication link of the mobile communication device with the base station based on mobility information received for the central communication link.
20. The method of claim 17, the method further comprising performing an outer loop processing comprising the numerology selection and/or a numerology configuration, wherein the outer loop processing is performed at a lower rate than a rate used for link adaptation between the base station and the mobile communication device.
21. The method of claim 20, the method further comprising re-configuring a radio bearer to different time-frequency resources having a numerology based on the mobility information.
22. The method of claim 17, the method further comprising triggering each of a shared hybrid automatic repeat request (HARQ) redundancy versions based on the mobility information to a different numerology.
23. The method of claim 17, the method further comprising selecting the numerology for at least one component carrier transmitting the radio signal.
24. The method of claim 17, the method further comprising inserting a predetermined pilot preamble into the radio signal, wherein the pilot preamble is configured to determine channel conditions, in particular the Doppler spread and/or the delay spread.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) Further embodiments of the present invention will be described with respect to the following figures, in which:
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DETAILED DESCRIPTION OF THE EMBODIMENTS
(14) In the following detailed description, reference is made to the accompanying drawings, which form a part thereof, and in which is shown by way of illustration exemplary aspects in which the disclosure may be practiced. It is understood that other aspects may be utilized and structural or logical changes may be made without departing from the scope of the present disclosure. The following detailed description, therefore, is not to be taken in a limiting sense, and the scope of the present disclosure is defined by the appended claims.
(15) It is understood that comments made in connection with a described method may also hold true for a corresponding device or system configured to perform the method and vice versa. For example, if a specific method step is described, a corresponding device may include a unit to perform the described method step, even if such unit is not explicitly described or illustrated in the figures. Further, it is understood that the features of the various exemplary aspects described herein may be combined with each other, unless specifically noted otherwise.
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(17) The base station 100 includes a second plurality of HARQ (Hybrid Automatic Repeat Request) entities 122, 123, 124 for transmission control of radio signals to be transmitted to UE2. An exemplary number of three such HARQ entities are depicted in
(18) In the following, an exemplary implementation of the numerology configuration management module 101 is described. The numerology configuration management module 101 can be used for dynamic configuration of resource for C-V2x. Numerology configuration management in the Base station's 100 RRM 101 can have the following functionalities:
(19) Base station 100 can dynamically adapt L1 configuration (i.e. numerology, time/frequency resource etc.) for each user based on the radio channel measurement to achieve certain QoS target in case of ultra-reliable low latency communication based on the MI (mobility information or mobility indicator) feedback.
(20) Every UE may have one primary numerology and one or more secondary numerology based on the capability of the UE, where each numerology may act as a separate carrier (CA, carrier aggregation), and aggregation of carrier with different numerology may be supported. Base station 100 can decide the primary numerology during initial access and/or connected mode based on the radio measurement information like mobility indicator (e.g. Doppler/delay spread estimate from UE) and/or Timing advance, SINR from UE.
(21) Base station 100 can move the primary numerology of the UE context from existing time/frequency resource with X numerology settings to different time/frequency resource with Y numerology settings. The numerology settings already supported by the Base station 100 may be based on the MI feedback.
(22) Base station 100 can support cross-carrier HARQ scheduling with different numerology based on the mobility indicator and SNR as described with respect to the below Figures.
(23) Base station 100 may reconfigure existing time/frequency resources for a sidelink communication (e.g. based on the assigned resource pools) via explicit signaling via DCI (downlink control information) or RRC (radio resource control) sidelink dedicated signaling to different numerology based on the feedback of mobility information from UE.
(24) Numerology configuration management can take care of numerology reconfiguration of radio bearer to suitable numerology based on the MI feedback, which may be present in the base station 100. RRM 101 may collect the physical layer measurement result from all UE tiles (or also named resource elements) and may keep record of the QoS requirement for every UE service.
(25) Numerology configuration management 101 can have an interface with RRC layer (using RRC dedicated signaling) for updating UE numerology reconfiguration depending on the service and physical layer parameter estimates.
(26) To achieve reliable retransmission scheme for HARQ in DL for variant channel conditions, each retransmission may be triggered by the base station 100 with different numerologies based on the decoded MI information, as described hereinafter with respect to the following figures.
(27) The different retransmission may be allocated to different FDM/TDM data regions with different numerologies as described below.
(28) During RRC dedicated bearer establishment procedure after the connected mode, the request can choose the numerology based on the priority of the request and the MI feedback at the time.
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(30) The BS 210 includes a base station RRM module 212 that may correspond to the RRM module 101 described above with respect to
(31) The UE 220 can transmit Delay and/or Doppler estimates 223 to the BS 210. These Delay and/or Doppler estimates 223 may be generated in a UE PHY measurement module, e.g. a UE PHY measurement module from V2N tiles 221 or a UE PHY measurement module from V2V tiles 222. In one example, the UE PHY measurement module from V2N tiles 221 can provide the measurements for a central link to BS 210 and the UE PHY measurement module from V2V tiles 222 can provide the measurements for a sidelink with another UE 220.
(32) In the following, an exemplary implementation of the Tile Configuration management module 213 in the BS 210 is described. Tile configuration management 213 in the Base station's RRM 212 may have the following functionality: Dynamic adaptation of L1 configuration of Users for each RAN slice based on the radio channel measurement to achieve certain QoS target; Base station 210 can move the UE context from existing tile with X numerology settings to different tile with Y numerology settings—provided the different tile settings already supported by the BS; Base station 210 can reconfigure existing tiles to different numerology based on the feedback of mobility information from UE 220. Tile configuration management 213 takes care of tiles reconfiguration, collects the physical layer measurement result from all UE tiles and keeps record of the QoS requirement for every UE service, e.g. indicated by the QoS module 214. Tile configuration management 213 has an interface with RRC layer (using RRC dedicated signaling 211) for updating UE tile reconfiguration depending on the service and physical layer parameter estimates.
(33) The UE 220 can generate UE centric estimates of quantized normalized Doppler and delay spread estimates with respect to subcarrier spacing/sampling frequency or CP length (referred to as mobility indicator) measured from Uu plane and Pc5 interface and can transmit these estimates to the Base station 210. The Base station RRM module 212 can decide numerology adaptation of a certain radio bearer in-case of Uu plane and Pc5 interface based on the UE centric estimates and can change the configuration of the radio bearer numerology settings with RRC reconfiguration message. In case of RRC dedicated bearer establishment in connected mode (UE connected in default mode), Base station 210 can assign the numerology configuration of the dedicated radio bearer based on the UE centric estimates received in connected mode (with default bearer). The base station 210 can change the primary numerology configuration of the UE 220 from setting x that was assigned during the connected mode to setting y based on the mobility indicator with help of RRC reconfiguration message in order to enable service continuity to provide certain reliability. Mobility indicator may include the Delay and/or Doppler estimates 223 measured by UE 220. To achieve reliable retransmission scheme for HARQ in DL for variant channel conditions, each retransmission can be triggered by the base station 210 with different numerologies based on the decoded MI information, e.g. the Delay and/or Doppler estimates 223 measured by UE 220. A unified Pilot sequence based on preamble across different numerologies, e.g. as described below with respect to
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(36) To achieve reliable retransmission scheme for HARQ in DL (e.g. from BS 210 to UE 220) for variant channel conditions, each retransmission 401, 402 can be triggered by the base station 210 with different numerologies 411, 412 based on the decoded MI information 403, 404. The different retransmission can be allocated to different FDM/TDM data regions with different numerologies as described above with respect to
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(39) In the BS 620, a processor implements outer loop processing 621 with adaptive numerology selection 623 that may correspond to the tile configuration management module 213 described above with respect to
(40) The functionality of the communication system 600 may correspond to the functionality described above for the communications system 200 of
(41) The communication system 600 allows implementation of hierarchical link adaptation (LA) with fast inner 622 and slow outer 621 loop, where the outer loop 621 is dedicated to the numerology adaptation for a particular tile.
(42) As shown in
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(44) In one exemplary implementation, the pilot pattern 700 may implement a DL (downlink) unified preamble based pilot design 701 (e.g. as Broadcast) for RRM measurement and adaptive pilot design 702 for channel estimation. The Pilot preambles 701 are arranged in time and Frequency for RRM measurement as follows: a unified Pilot 701 is arranged across different numerologies to estimate the Doppler Delay Spreads. The periodicity of the sub-frames carrying pilot preambles can be dynamically decided by the base station. In one implementation the preamble is not required every sub-frame, since the estimation is needed only for Doppler and delay spread which do not vary much. Uniform Doppler-delay spread estimates due to RRM measurement signal helps in adaptive pilot distribution for estimating the channel conditions: This can be achieved by using Scattered Pilots 702 as shown in
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(46) In a C-V2x scenario the method 800 can be implemented as follows: Mobility indicator content is reported via UE measurement reporting to BS's tile configuration management. Base station Tile configuration management is responsible for mapping the mobility indicator value to the particular numerology system settings. Re-configuration of numerology settings for that user (e.g. based on the measurement report) may be done via RRC dedicated signaling (e.g. by RRC re-configuration message).
(47) In a V2V scenario for sidelink, the method 800 can be implemented as follows: UE can decide to change the numerology based on its own measurements and threshold, then informs the BS via RRC measurement report. Then the BS can re-configure to D2D UEs (or UEs involved in cooperative communication) to a selected numerology via RRC re-configuration.
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(49) Tile configuration management 911 in base station's 910 RRM knows the UE PHY measurement 913 which includes MI feedback information 914 from different tiles and their corresponding QoS service requirements 912.
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(51) In the following, an exemplary implementation to compute mobility information is described. A table according to Table 1 illustrated below may be used to map mobility index to mobility information, which includes estimates about coherence time and bandwidth.
(52) TABLE-US-00001 TABLE 1 exemplary implementation to determine the mobility information Mobility Index Mobility information includes estimates about coherence time and bandwidth Relative speed From the Doppler shift, subcarrier model can be from Sensor adapted for line of sight communication Sub-band CQI report: Averaging CQI over time for a longer duration require more signaling provides useful information about Doppler; resource + Relative Precision depends on the CQI periodicity. In speed from sensor general if the coherence time of the channel is smaller than the CQI periodicity then the estimate is not accurate. Also to know about the coherence BW, estimates from the entire band are required for a longer duration. Sub-band CQI estimate together with relative speed from sensor can provide information about Doppler. Delay and Provides second order accurate statistical Doppler spread information about the Doppler and delay spread estimates + SNR Doppler and delay spread together with estimated SNR could be used to adapt the numerology model effectively.
(53) The UE can use Mobility Information (MI) to provide the base station with feedback regarding channel condition. The Mobility indicator (MI) enables signaling of UE specific information on the experienced time-varying channel conditions, e.g. in terms of Doppler and multipath to BS. This facilitates numerology adaptation, i.e., subcarrier spacing, cyclic prefix to maintain certain QoS target.
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(55) The receiver 1001 is configured to receive a radio signal 1002 over a radio channel. The radio signal 1002 includes a predetermined pilot preamble, e.g. a pilot pattern 700 as described above with respect to
(56) The processor 1003 may be configured to provide the mobility information 1004 as a combined value of Delay Spread and Doppler Spread estimate to the second communication device 1100.
(57) The mobility information 1004 may further include a channel quality information (CQI) indicator 612 and a hybrid automatic repeat request (HARQ) indicator 614, e.g. as described above with respect to
(58) The pilot preamble 700 may include a first part 702 (i.e. a pilot of a first type) configured to estimate the radio channel and a second part 701 (i.e. a pilot of a second type) configured to estimate the Doppler and/or Delay Spread, e.g. as described above with respect to
(59) The communication device 1000 may include a user equipment, e.g. a UE 610 as described above with respect to
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(61) The processor 1103 may be configured to select the numerology 301, 302, 303, 304 based on a metric used to evaluate the mobility information 1004 with respect to a Quality-of-Service requirement. The processor 1103 may be configured: to select a numerology 301, 302, 303, 304 for a sidelink communication of the communication device based on mobility information received for the sidelink, and to select a numerology for a central communication link, e.g. a central communication link 914 as shown in
(62) The processor 1103 may be configured: to process an outer loop 621 including the numerology selection 623 and numerology configuration, e.g. as described above with respect to
(63) As shown in
(64) The processor 1103 may be configured to select the numerology 115, 116, 117, 125, 126, 127 for at least one component carrier transmitting the radio signal, e.g. as described above with respect to
(65) The processor 1103 may be configured to insert a predetermined pilot preamble 701 into the radio signal 1104, e.g. as described above with respect to
(66) The processor 1103 may be configured: to receive a request for a new dedicated radio bearer from the communication device 1000, in particular a user equipment 922 in connected mode, and to configure a numerology 301, 302, 303, 304 of the new dedicated radio bearer based on a QoS priority of the requested radio bearer with prior measurement knowledge about Doppler and delay spread estimates obtained when the communication device 1000, 922 is connected to the base station 1100, 910, e.g. as shown in
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(68) The method 1200 includes receiving 1201 mobility information, in particular a Doppler and/or a Delay Spread, signaled by a mobile communication device, e.g. a mobile communication device 1000 described above with respect to
(69) The present disclosure also supports a computer program product including computer executable code or computer executable instructions that, when executed, causes at least one computer to execute the performing and computing steps described herein, in particular the steps of the methods described above. Such a computer program product may include a readable non-transitory storage medium storing program code thereon for use by a computer. The program code may perform the processing and computing steps described herein, in particular the method 1200 described above with respect to
(70) While a particular feature or aspect of the disclosure may have been disclosed with respect to only one of several implementations, such feature or aspect may be combined with one or more other features or aspects of the other implementations as may be desired and advantageous for any given or particular application. Furthermore, to the extent that the terms “include”, “have”, “with”, or other variants thereof are used in either the detailed description or the claims, such terms are intended to be inclusive in a manner similar to the term “comprise”. Also, the terms “exemplary”, “for example” and “e.g.” are merely meant as an example, rather than the best or optimal. The terms “coupled” and “connected”, along with derivatives may have been used. It should be understood that these terms may have been used to indicate that two elements cooperate or interact with each other regardless whether they are in direct physical or electrical contact, or they are not in direct contact with each other.
(71) Although specific aspects have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that a variety of alternate and/or equivalent implementations may be substituted for the specific aspects shown and described without departing from the scope of the present disclosure. This application is intended to cover any adaptations or variations of the specific aspects discussed herein.
(72) Although the elements in the following claims are recited in a particular sequence with corresponding labeling, unless the claim recitations otherwise imply a particular sequence for implementing some or all of those elements, those elements are not necessarily intended to be limited to being implemented in that particular sequence.
(73) Many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the above teachings. Of course, those skilled in the art readily recognize that there are numerous applications of the invention beyond those described herein. While the present invention has been described with reference to one or more particular embodiments, those skilled in the art recognize that many changes may be made thereto without departing from the scope of the present invention. It is therefore to be understood that within the scope of the appended claims and their equivalents, the invention may be practiced otherwise than as specifically described herein.