Method and apparatus for receiving downlink data in wireless communication system

Patent metadata

Field	Value
Publication number	US-9955487-B2
Application number	US-201514668212-A
Country	US
Kind code	B2
Filing date	Mar 25, 2015
Priority date	Mar 28, 2014
Publication date	Apr 24, 2018
Grant date	Apr 24, 2018

Abstract

A method for receiving downlink data by a User Equipment (UE) in a wireless communication system is provided. The method includes checking a transmission parameter related to data transmitted from an interfering cell, determining presence/absence of an interference signal based on the transmission parameter, determining whether to apply Network Assisted Interference Cancellation and Suppression (NAICS) technology based on at least one of the transmission parameter or the presence/absence of the interference signal, and decoding the downlink data depending on whether to apply the NAICS technology.

First claim

What is claimed is:

1. A method for receiving downlink data in a wireless communication system, the method comprising:
checking, by a user equipment (UE), a transmission parameter related to data transmitted from an interfering cell;
determining, by the UE, whether a demodulation reference signal (DMRS)-based interference signal is present or not based on the transmission parameter;
determining, by the UE, whether a cell specific reference signal (CRS)-based interference signal is present or not based on the transmission parameter, if the DMRS-based interference signal is not present;
determining, by the UE, whether to apply network assisted interference cancellation and suppression (NAICS) technology based on at least one of the transmission parameter or whether the interference signal is present or not;
decoding, by the UE, the downlink data depending on whether to apply the NAICS technology;
generating a DMRS sequence using the transmission parameter; and
calculating a log likelihood ratio (LLR) by applying the NAICS to remove the interference signal, or calculating a LLR by considering the interference signal,
wherein the DMRS-based interference signal is determined to be present or not with respect to an antenna port whose port number p is 7 or 8, and
wherein the downlink data is decoded using the calculated LLR.

2. The method of claim 1 , wherein the checking of the transmission parameter comprises:
receiving information including the transmission parameter from a serving cell through signaling, or blind-detecting the information including the transmission parameter.

3. The method of claim 1 ,
wherein the transmission parameter includes enhanced physical downlink control channel (ePDCCH) information of the interfering cell, and
wherein the determining of whether to apply the NAICS based on the transmission parameter comprises determining not to apply the NAICS, if the ePDCCH information of the interfering cell indicates that a control channel of the interference signal is set as an ePDCCH.

4. The method of claim 1 ,
wherein the transmission parameter includes a physical downlink shared channel (PDSCH) transmission mode of the interfering cell, and
wherein the determining of whether to apply the NAICS based on the transmission parameter comprises determining not to apply the NAICS, if the PDSCH transmission mode of the interfering cell includes a specific transmission mode.

5. The method of claim 1 ,
wherein the transmission parameter includes a physical downlink shared channel (PDSCH) transmission mode of the interfering cell,
wherein the determining of whether to apply the NAICS based on the transmission parameter comprises determining to apply the NAICS, if the PDSCH transmission mode of the interfering cell includes a specific transmission mode, and
wherein the specific transmission mode is a CRS-based transmission mode or a DMRS-based transmission mode.

6. The method of claim 1 , wherein the determining of whether the DMRS-based interference signal is present or not comprises:
determining whether the DMRS-based interference signal is present or not, if the checked transmission parameter does not include a PDSCH transmission mode of the interfering cell.

7. The method of claim 1 , wherein the determining of whether to apply the NAICS based on whether the interference signal is present or not comprises determining to apply the NAICS, if the DMRS-based interference signal is present.

8. The method of claim 1 , further comprising:
estimating a channel of the DMRS-based interference signal using the generated DMRS sequence,
wherein the DMRS-based interference signal is determined to be present or not with respect to the antenna port whose port number p is 7 or 8 based on the estimated channel.

9. The method of claim 1 , wherein the LLR is calculated by a conditional probability density function in which statistical characteristics of the interference signal are reflected.

10. The method of claim 1 , wherein the transmission parameter includes at least one of port number information of the interfering cell, a physical cell identifier (ID), a virtual cell ID, a scrambling ID, a transmission mode of a physical downlink shared channel (PDSCH), enhanced physical downlink control channel (ePDCCH) information, slot number information, or information about a number of antenna ports.

11. A user equipment (UE) for receiving downlink data in a wireless communication system, the UE comprising:
a controller configured to:
check a transmission parameter related to data transmitted from an interfering cell,
determine whether a demodulation reference signal (DMRS)-based interference signal is present or not based on the transmission parameter,
determine whether a cell specific reference signal (CRS)-based interference signal is present or not based on the transmission parameter, if the DMRS-based interference signal is not present,
determine whether to apply network assisted interference cancellation and suppression (NAICS) technology based on at least one of the transmission parameter or whether the interference signal is present or not,
decode the downlink data depending on whether to apply the NAICS technology,
generate a DMRS sequence using the transmission parameter, and
calculate a log likelihood ratio (LLR) by applying the NAICS to remove the interference signal, or calculate a LLR by considering the interference signal; and

a receiver configured to receive the downlink data under control of the controller,
wherein the DMRS-based interference signal is determined to be present or not with respect to an antenna port whose port number p is 7 or 8, and
wherein the downlink data is decoded using the calculated LLR.

12. The UE of claim 11 , wherein the controller is further configured to receive information including the transmission parameter from a serving cell through signaling, or blind-detect the information including the transmission parameter.

13. The UE of claim 11 ,
wherein the transmission parameter includes enhanced physical downlink control channel (ePDCCH) information of the interfering cell, and
wherein the controller is further configured to determine not to apply the NAICS, if the ePDCCH information of the interfering cell indicates that a control channel of the interference signal is set as an ePDCCH.

14. The UE of claim 11 ,
wherein the transmission parameter includes a physical downlink shared channel (PDSCH) transmission mode of the interfering cell, and
wherein the controller is further configured to determine not to apply the NAICS, if the PDSCH transmission mode of the interfering cell includes a specific transmission mode.

15. The UE of claim 11 ,
wherein the transmission parameter includes a physical downlink shared channel (PDSCH) transmission mode of the interfering cell,
wherein the controller is further configured to determine to apply the NAICS, if the PDSCH transmission mode of the interfering cell includes a specific transmission mode, and
wherein the specific transmission mode is a CRS-based transmission mode or a DMRS-based transmission mode.

16. The UE of claim 11 , wherein the controller is further configured to determine whether the DMRS-based interference signal is present or not, if the checked transmission parameter does not include a PDSCH transmission mode of the interfering cell.

17. The UE of claim 11 , wherein the controller is further configured to apply the NAICS, if the DMRS-based interference signal is present.

18. The UE of claim 11 ,
wherein the controller

Assignees

• Samsung Electronics Co Ltd

Inventors

• Shin Cheol-Kyu
• Lee Hyo-Jin
• Lee Heun-Chul
• Kim Young-Bum
• Kim Youn-Sun

Classifications

• H04L1/0047

  Decoding adapted to other signal detection operation (in conjunction with sequence estimation or equalization H04L25/03286) · CPC title

• H04J11/0023 Primary

  Interference mitigation or co-ordination (direct sequence spread spectrum [DSSS] systems H04B1/7097; frequency hopping H04B1/713; allocation criteria for ingress interference avoidance H04L5/0062; frequency allocation criteria for requirements on out-of-channel emissions H04L5/0066; arrangements for removing intersymbol interference or baseband equalisers H04L25/03006; peak power aspects in multicarrier modulation H04L27/2614; power management H04W52/00; traffic scheduling H04W72/54, H04W72/541) · CPC title

• H04W72/541 Primary

  using the level of interference · CPC title

• H04L5/0023

  Time-frequency-space · CPC title

• H04L5/0048

  Allocation of pilot signals, i.e. of signals known to the receiver (allocation of control signalling H04L5/0053; use of control signalling H04L5/0091) · CPC title