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EP-4738960-A2 - COMMUNICATION DEVICES, COMMUNICATION COORDINATING DEVICES, AND COMMUNICATION METHODS

EP4738960A2EP 4738960 A2EP4738960 A2EP 4738960A2EP-4738960-A2

Abstract

There is disclosed a communication device (e.g. 204, 252-254) for communicating with one or more other communication devices using a multiple-input-multiple-output, MIMO, communication, configured to: - (e.g. 102) select one or more preferred beams (e.g. 302); and - (e.g. 104) find one or more other beams (e.g. 301b, 305, 305b) which have a comparatively high spatial correlation with the one or more preferred beams (e.g. 302) or which have a comparatively high probability of interference with the one or more preferred beams (e.g. 302).

Inventors

  • KURRAS, Martin
  • THIELE, LARS
  • Grossmann, Marcus
  • HADASCHIK, Niels
  • HAUSTEIN, THOMAS
  • NAM, JUNYOUNG

Assignees

  • Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V.

Dates

Publication Date
20260506
Application Date
20190409

Claims (16)

  1. A communication device (204, 252-254) for communicating with one or more other communication devices using a multiple-input-multiple-output, MIMO, communication, wherein the communication device (204, 252-254) is configured to: • select one or more preferred beams (302); and • find one or more other beams (301b, 305, 305b) which have a comparatively high correlation with the one or more preferred beams (302), wherein the communication device (204, 252-254) is configured to provide, to a coordinating communication device (204, 251): • first information (210) identifying the one or more preferred beams (302); and • second information (212) identifying the one or more found other beams (301b, 305, 305b).
  2. The communication device (204, 252-254) of claim 1, wherein the one or more preferred beams (302) and/or the one or more other beams (301b, 305, 305b) are beams received from multiple coordinating communication devices (204, 251).
  3. The communication device (204, 252-254) of any of the preceding claims, configured to: • evaluate or estimate channel information associated to beams (301, 301b, 305) different from the one or more preferred beams (302); • on the basis of the evaluated or estimated channel information, provide the one or more found other beams (301b, 305, 305b) as the second information (212).
  4. The communication device (204, 252-254) of any of the preceding claims, configured to: • evaluate or estimate channel information associated to beams (301, 301b, 305) different from the one or more preferred beams (302) to find the one or more other beams (301b, 305, 305b).
  5. The communication device (204, 252-254) of claim 4, configured to: • verify whether the channel information is greater than a first threshold to find the one or more other beams (301b, 305, 305b).
  6. The communication device (204, 252-254) of any of the preceding claims, configured to: • evaluate or estimate channel information for beams (305) which are not the preferred beams (302); • retrieve highly correlated beams (305) which maximize an interference condition with the preferred beams (302); • provide information of the highly correlated beams (305) as the second information (212).
  7. The communication device (204, 252-254) of any of claims 3-6, wherein the channel information includes an Interference to Noise Ratio, INR.
  8. The communication device (204, 252-254) of any of claims 3-7, wherein the channel information is derived from a signal to noise ratio, SNR, and/or an Interference to Noise Ratio, INR.
  9. The communication device (204, 252-254) of any of claims 3-8, configured to calculate the channel information based on received reference symbols (CSI-RS).
  10. The communication device (204, 252-254) of any of the preceding claims, configured to create an ordered list of best beam candidates and to provide them to the coordinating communication device (204, 251).
  11. The communication device (204, 252-254) of any of the preceding claims, wherein the found one or more other beams (301b, 305, 305b) are beams which, if transmitted simultaneously to the one or more preferred beams (302), would cause interference.
  12. The communication device (204, 252-254) of any of the preceding claims, wherein the one or more other beams (301b, 305, 305b) which have a comparatively high correlation with the one or more preferred beams (302) have high spatial correlation.
  13. The communication device (204, 252-254) of any of the preceding claims, wherein the one or more other beams (301b, 305, 305b) which have a comparatively high correlation with the one or more preferred beams (302) have high receive correlation.
  14. The communication device (204, 252-254) of any of the preceding claims, configured to perform channel measurement on the basis of an unprecoded Channel State Information reference symbol, CSI-RS, received from the coordinating communication device (204, 251).
  15. A method comprising: • selecting (102) one or more preferred beams (302); and • finding (104) one or more other beams (301b, 305, 305b) which have a comparatively high correlation with the one or more preferred beams (302), • retrieving: ∘ first information (210) identifying the one or more preferred beams (302); and ∘ second information (212) identifying the one or more found other beams (301b, 305, 305b) or a region in a map of beams (300) comprising the one or more found other beams (301b, 305, 305b).
  16. A non-transitory storage unit storing instructions which, when executed by a computer, cause the computer to perform the method of claim 15.

Description

1. Technical field The present document relates to examples of communication devices (e.g., user equipment s, US), e.g., for communicating with one or more other communication devices, e.g., using a multiple-input-multiple-output, MIMO, communication, e.g., a multi-user MIMO, MU-MIMO, communication. The present document also relates to coordinating communication devices (BS, gNBs) for communicating with one or more other communication devices using a multiple-input-multiple-output, MIMO, communication, e.g., a multi-user MIMO, MU-MIMO, communication. The communications may be carried out, for example, using devices which have multi-antenna arrays and/or which may perform uplink (UL) and/or downlink (DL) beamed transmissions using spatial codes (e.g., obtained from a known codebook). 1.1 Prior art The prior art comprises the following disclosures: [1] 3GPP TR 36.897 V13.0.0, "3rd Generation Partnership Project; Technical Specification Group Radio Access Network; Study on elevation beamforming / Full-Dimension (FD) Multiple Input Multiple Output (MIMO) for LTE (Release 13)," June 2015.[2] J. Nam et. al, "Method for multi-input multi-output communication in large-scale antenna system," KR/EP/US patent (US 14/200,557, EP 2775634A3). Multi-user (MU) MIMO has been a main driver to improve the spectral efficiency of wireless communication systems including LTE and WiFi. However, the current MU-MIMO in LTE still does not provide a significant performance improvement compared to the performance of single-user MIMO. Main reasons for the poor MU-MIMO performance in LTE can be characterized as follows: 1. Coarse limited CSI feedback ∘ Only a small amount of CSI quantization bits is allowed due to feedback overhead2. Scheduling loss ∘ difficult to find a good subset of users because there is no actual information on mutual inter-user interference3. Link adaptation losses ∘ Link adaptation implies that, according to the estimated SINR, a user k selects a CQI which corresponds to a desired MCS. This selection usually aims for a certain block error rate (BLER). The smaller the difference between the estimated and true SINR, the smaller the link-adaptation loss. There are two types of link-adaptation loss. ▪ First, if the estimated SINR is larger than the true SINR the BLER increases and reduces the realized data-rate.▪ Second, if the estimated SINR is lower, than a lower data-rate is realized than possible by the channel link capacity.∘ In LTE, users report their CQI based on the estimated SNR resulting to average realized data rates much lower than theoretically possible. While the above first two factors are well understood in both academy and industry, the third aspect has not been properly addressed and has been actually ignored. 2. The present invention According to an aspect, there is provided a communication device for communicating with one or more other communication devices using a multiple-input-multiple-output, MIMO, communication, wherein the communication device is configured to: select one or more preferred beams; andfind one or more other beams which have a comparatively high spatial correlation with the one or more preferred beams or which have a comparatively high probability of interference with the one or more preferred beams,wherein the communication device is configured to provide, to a coordinating communication device: first information identifying the one or more preferred beams; andsecond information identifying the one or more found other beams or a region in a map of beams comprising the one or more found other beams. According to an aspect, there is provided a communication device for communicating with one or more other communication devices using a multiple-input-multiple-output, MIMO, communication, wherein the communication device is configured to obtain, from a coordinating communication device: first signalling information identifying the one or more requested beams in the region; andsecond signalling information identifying a region in a map of beams comprising the one or more requested beam,wherein the communication device is configured to perform the following operations in the region identified by the second signalling information: evaluate or estimate interference information associated to beams; and: ∘ on the basis of the evaluated or estimated interference information, retrieve at least the highest interfering beam and signal the at least the highest interfering beam to the coordinating communication device; and/or∘ on the basis of the evaluated or estimated interference information, retrieve information on the interference within the region identified by the second signalling information and provide it to the coordinating communication device. The communication device may be as above. The communication device may be configured to: evaluate or estimate interference information associated to beams different from the one or more preferred beams;on the basis of the evaluated or estima