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US-20260128824-A1 - SOUNDING FEEDBACK UTILIZING SHORTENED FRAME STRUCTURES

US20260128824A1US 20260128824 A1US20260128824 A1US 20260128824A1US-20260128824-A1

Abstract

Embodiments provide a transceiver, wherein the transceiver is configured to transmit or receive data in at least one transmission time interval on certain allocated resource elements of a wireless communication system, wherein the transceiver is configured to at least partially blank a transmission time interval for a data block to be transmitted or received by the transmitter, wherein the transceiver is configured (a) to signal to another transceiver a transmission grant in a blanked part of the at least partially blanked transmission time interval or (b) to at least partially blank the transmission time interval based on a blanking pattern received from another transceiver.

Inventors

  • Thomas Fehrenbach
  • Baris GOEKTEPE
  • Thomas Haustein
  • Thomas Wirth
  • Lars Thiele

Assignees

  • FRAUNHOFER-GESELLSCHAFT ZUR FOERDERUNG DER ANGEWANDTEN FORSCHUNG E.V.

Dates

Publication Date
20260507
Application Date
20250723
Priority Date
20160811

Claims (20)

  1. 1 . A transceiver, wherein the transceiver is configured to receive data in at least one slot on certain allocated resource elements of a wireless communication system; wherein the transceiver is configured to receive a blanking pattern from another transceiver; wherein the transceiver is configured to receive data in the slot using the blanking pattern, wherein the transceiver is configured to receive data using a data signal, the data signal comprising a plurality of frames, each frame comprising a plurality of subframes, and each subframe comprising a number of symbols in the time domain and a number of sub-carriers in the frequency domain, wherein the slot is defined by a predefined number of symbols in the time domain, wherein the slot is shorter than one subframe.
  2. 2 . (canceled)
  3. 3 . (canceled)
  4. 4 . The transceiver of claim 1 , configured to at least partially blank the slot by one or more of the following: by blanking at least a subset of symbols in the time domain of the slot, by blanking at least a subset of sub-carriers in the frequency domain of the slot, by blanking at least a subset of resource elements of the slot in at least one out of time domain and frequency domain.
  5. 5 . (canceled)
  6. 6 . (canceled)
  7. 7 . The transceiver of claim 1 , configured to signal to another transceiver a transmission grant for transmitting a reference signal in a blanked part of the at least partially blanked slot.
  8. 8 . (canceled)
  9. 9 . The transceiver of claim 1 , configured to blank at least one out of demodulation reference symbols and data symbols in the at least partially blanked slot.
  10. 10 . (canceled)
  11. 11 . The transceiver of claim 1 , configured to only transmit at least one out of reference symbols and demodulation reference symbols in the at least partially blanked slot.
  12. 12 . (canceled)
  13. 13 . The transceiver of claim 1 , configured to partially blank parts of the slot in at least one part out of time domain and frequency domain.
  14. 14 . The transceiver of claim 1 , configured to use a blanked part of the at least partially blanked slot for transmitting or receiving a reference signal.
  15. 15 . (canceled)
  16. 16 . (canceled)
  17. 17 . (canceled)
  18. 18 . (canceled)
  19. 19 . (canceled)
  20. 20 . (canceled)

Description

CROSS-REFERENCES TO RELATED APPLICATIONS This application is a continuation of copending U.S. patent application Ser. No. 18/511,755 filed Nov. 16, 2023, which is a continuation of U.S. patent application Ser. No. 17/879,558 filed Aug. 2, 2022 (U.S. Pat. No. 11,848,877 issued Dec. 19, 2023), which is a continuation of U.S. patent application Ser. No. 16/271,438, filed Feb. 8, 2019 (U.S. Pat. No. 11,463,224 issued Oct. 4, 2022), which in turn is a continuation of International Application No. PCT/EP 2017/069815, filed Aug. 4, 2017, which is incorporated herein by reference in its entirety, and additionally claims priority from European Application No. EP 16 183 898.2, filed Aug. 11, 2016, which is incorporated herein by reference in its entirety. BACKGROUND OF THE INVENTION The present invention concerns the field of wireless communication systems, for example wireless mobile communication systems, in which data is transmitted from a transmitter to one or more receivers, like mobile terminals. The transmitters may be base stations of the wireless communication system or other mobile terminals. The receiver may be base stations of the wireless communication system or other mobile terminals. If transmitter and receiver is a mobile terminal, the communication link is referred to as sidelink. Advanced MIMO systems with many antenna ports, such as Full Dimension (FD)-MIMO or massive MIMO systems, need fast and efficient feedback mechanisms to characterize the radio channel between base station (eNB) and user equipment (UE or uE). So-called channel state information (CSI) is used for choosing the best transmission strategy. Special sounding reference signals (SRS) can be used to estimate link (uplink, downlink, sidelink) channel quality over a wider bandwidth. With a high number of antenna ports, e.g. [16, 32, 64, >100] antenna ports, the number of resource elements (RE) used for transmitting feedback symbols increases, which results in a large overhead of symbols transmitted for control traffic, when compared to symbols available for transmitting data symbols. Thus, the overhead-to-data ratio becomes worse with an increasing number of antenna ports. Furthermore, accurate beamforming needs fast feedback in the reverse link, e.g. uplink (UL) or sidelink of the communication system, such that the collected channel state information from the particular UE is still “valid”, implying that the signaling can be performed within the coherence time of the fading radio channel. In current frequency division duplex (FDD) systems, channel reciprocity (using the same frequency band also in UL direction and deriving CSI from the reciprocal link) cannot be utilized to derive CSI for the downlink (DL). Thus, the UE has to calculate CSI from the DL transmission and feed this information back in the UL direction. This needs the UE to store this feedback information (memory requirements), as well as waiting for an uplink slot (uplink grant) for transmitting CSI feedback in the UL. In TDD system, DL and UL subframe configuration is limited to the specified modes, including subframes used for switching(S) between DL and UL. The current TDD configurations limit channel feedback to the available reverse link (e.g. UL) time slot, which can lead to outdated CSI at the transmitter, which is waiting for this CSI to be used for precoding. In summary, in both FDD and TDD systems, the current mechanisms may cause a feedback delay, resulting in outdated feedback at the transmitter, e.g. base station in the DL or terminal in a sidelink communication, if the channel has changed in the meantime, e.g. the feedback cannot be utilized at the transmitter within the coherence bandwidth of the fading channel. A resulting transmission with outdated CSI precoding will lead to inefficient or even loss of data packets in the data transmission and might cause an increased overhead, e.g. caused by resource elements used for retransmission protocols (such as hybrid automatic repeat request (HARQ)). LTE sounding reference symbols (SRS) is a reference signal sent by the UE, which is used by the corresponding base station (eNB) to evaluate the channel quality of uplink path and uplink timing transmission, see 3GPP TS 36.211-§ 5.5.3 [1 ]. The UE sounding procedure is defined in 3GPP TS 36.213-§ 8.2 [2 ]. A UE shall transmit sounding reference symbol (SRS) on per serving cell SRS resources based on two different trigger types: higher layer signaling or based on specific DCI formats for FDD or TDD systems. SRS may be transmitted as ‘single’ or ‘periodic’ information. The periodicity ranges from 2 ms to 320 ms. In addition, the used SRS bandwidth, hopping bandwidth, the frequency domain position of SRS, a cyclic shift to generate up to 8 different, orthogonal SRS sequences. Furthermore, a ‘transmissionComb’ can be specified which allows to multiplex two UEs with the same cyclic shift in alternating frequency and time resources. The sequence of SRS's use same sequence