R1-1701161.zip_5G Communications_其他下载-pudn.com

<html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta charset="utf-8"> <meta name="generator" content="pdf2htmlEX"> <meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1"> <link rel="stylesheet" href="https://static.pudn.com/base/css/base.min.css"> <link rel="stylesheet" href="https://static.pudn.com/base/css/fancy.min.css"> <link rel="stylesheet" href="https://static.pudn.com/prod/directory_preview_static/627554489221806f9d32de80/raw.css"> <script src="https://static.pudn.com/base/js/compatibility.min.js"></script> <script src="https://static.pudn.com/base/js/pdf2htmlEX.min.js"></script> <script> try{ pdf2htmlEX.defaultViewer = new pdf2htmlEX.Viewer({}); }catch(e){} </script> <title></title> </head> <body> <div id="sidebar" style="display: none"> <div id="outline"> </div> </div> <div id="pf1" class="pf w0 h0" data-page-no="1"><div class="pc pc1 w0 h0"><img class="bi x0 y0 w1 h1" alt="" src="https://static.pudn.com/prod/directory_preview_static/627554489221806f9d32de80/bg1.jpg"><div class="c x0 y1 w2 h2"><div class="t m0 x1 h3 y2 ff1 fs0 fc0 sc0 ls0 ws0">3GPP TSG-RAN WG1 #87ah-NR R1-1701161</div><div class="t m0 x1 h3 y3 ff1 fs0 fc0 sc0 ls0 ws0">Spokane, WA, USA, 16</div><div class="t m0 x2 h4 y4 ff1 fs1 fc0 sc0 ls0 ws0">th</div><div class="t m0 x3 h3 y3 ff1 fs0 fc0 sc0 ls0 ws0"> – 20</div><div class="t m0 x4 h4 y4 ff1 fs1 fc0 sc0 ls0 ws0">th</div><div class="t m0 x5 h3 y3 ff1 fs0 fc0 sc0 ls0 ws0"> January, 2017</div><div class="t m0 x1 h3 y5 ff1 fs0 fc0 sc0 ls0 ws0">Source: Ericsson</div><div class="t m0 x1 h3 y6 ff1 fs0 fc0 sc0 ls0 ws0">Title: SRS design</div><div class="t m0 x1 h3 y7 ff1 fs0 fc0 sc0 ls0 ws0">Title: On DL and UL phase noise tracking RS (PTRS)</div><div class="t m0 x1 h3 y8 ff1 fs0 fc0 sc0 ls0 ws0">Agenda Item: 5.1.2.3.3</div><div class="t m0 x1 h3 y9 ff1 fs0 fc0 sc0 ls0 ws0">Document for: Discussion and Decision</div><div class="t m0 x1 h5 ya ff2 fs2 fc0 sc0 ls0 ws0">1 Introduction</div><div class="t m0 x1 h3 yb ff2 fs0 fc0 sc0 ls0 ws0">In RAN1#87, the following agreement was made regarding a PT-RS:</div><div class="t m0 x1 h5 yc ff2 fs2 fc0 sc0 ls0 ws0">2 Introduction</div><div class="t m0 x1 h3 yd ff2 fs0 fc0 sc0 ls0 ws0">Phase noise is present in any practical communication system, and impact the system by introducing</div><div class="t m0 x1 h3 ye ff2 fs0 fc0 sc0 ls0 ws0">random phase variations of the received signal. For an OFDM system, this will lead to inter-carrier</div><div class="t m0 x1 h3 yf ff2 fs0 fc0 sc0 ls0 ws0">interference as well as to a common phase error (CPE) on all subcarriers. With increasing carrier frequency,</div><div class="t m0 x1 h3 y10 ff2 fs0 fc0 sc0 ls0 ws0">the variance of the phase noise increases, leading more pronounced problems. For NR, targeting carrier</div><div class="t m0 x1 h3 y11 ff2 fs0 fc0 sc0 ls0 ws0">frequencies of 6 GHz and above, measures need to be taken to reduce phase noise induced degradation of</div><div class="t m0 x1 h3 y12 ff2 fs0 fc0 sc0 ls0 ws0">system performance. </div><div class="t m0 x6 h6 y13 ff3 fs3 fc0 sc0 ls0 ws0">1/10</div></div><div class="t m0 x7 h3 y14 ff1 fs0 fc0 sc0 ls0 ws0">Agreements:</div><div class="t m0 x8 h3 y15 ff2 fs0 fc0 sc0 ls0 ws0">• RS for Phase tracking is denoted as PT-RS</div><div class="t m0 x9 h3 y16 ff2 fs0 fc0 sc0 ls0 ws0">• FFS: Naming of RS</div><div class="t m0 x8 h3 y17 ff2 fs0 fc0 sc0 ls0 ws0">• PT-RS supports the following for CP-OFDM: </div><div class="t m0 x9 h3 y18 ff2 fs0 fc0 sc0 ls0 ws0">• Time-domain density of mapped on every other symbol and/or every symbol and/or </div><div class="t m0 xa h3 y19 ff2 fs0 fc0 sc0 ls0 ws0">every 4-th symbol</div><div class="t m0 xb h3 y1a ff2 fs0 fc0 sc0 ls0 ws0">• FFS: Whether/how to down-select the time-domain density</div><div class="t m0 xb h3 y1b ff2 fs0 fc0 sc0 ls0 ws0">• Note: Other time-domain densities of PT-RS are not precluded</div><div class="t m0 x9 h3 y1c ff2 fs0 fc0 sc0 ls0 ws0">• At least for UL </div><div class="t m0 xb h3 y1d ff2 fs0 fc0 sc0 ls0 ws0">• The presence of PT-RS is UE-specifically configured</div><div class="t m0 xc h3 y1e ff2 fs0 fc0 sc0 ls0 ws0">– FFS: Whether implicit and/or explicit UE-specific configuration is </div><div class="t m0 xd h3 y1f ff2 fs0 fc0 sc0 ls0 ws0">supported</div><div class="t m0 xb h3 y20 ff2 fs0 fc0 sc0 ls0 ws0">• PT-RS is confined in the scheduled time/frequency duration for a UE</div><div class="t m0 x9 h3 y21 ff2 fs0 fc0 sc0 ls0 ws0">• FFS: UE-specific and/or non-UE-specific and/or cell-specific for DL</div><div class="t m0 x8 h3 y22 ff2 fs0 fc0 sc0 ls0 ws0">• The following are to be studied for PT-RS:</div><div class="t m0 x9 h3 y23 ff2 fs0 fc0 sc0 ls0 ws0">• Number of PT-RS ports to be supported</div><div class="t m0 x9 h3 y24 ff2 fs0 fc0 sc0 ls0 ws0">• Use of precoding </div><div class="t m0 x9 h3 y25 ff2 fs0 fc0 sc0 ls0 ws0">• QCL relationship with other RS, e.g., DM-RS </div><div class="t m0 x9 h3 y26 ff2 fs0 fc0 sc0 ls0 ws0">• Details on frequency domain pattern(s) and/or variable frequency domain densities</div><div class="t m0 x9 h3 y27 ff2 fs0 fc0 sc0 ls0 ws0">• Whether PT-RS is necessary for DFT-s-OFDM waveform</div><div class="t m0 x9 h3 y28 ff2 fs0 fc0 sc0 ls0 ws0">• Sharing of time/frequency resource between PT-RS among UEs and/or among layers </div><div class="t m0 xa h3 y29 ff2 fs0 fc0 sc0 ls0 ws0">of a single UE</div><div class="t m0 x9 h3 y2a ff2 fs0 fc0 sc0 ls0 ws0">• Additional usage for estimating residual frequency offset and/or high-speed channel</div><div class="t m0 x9 h3 y2b ff2 fs0 fc0 sc0 ls0 ws0">• Possible method(s) to improve phase estimation performance from PT-RS</div><div class="t m0 xb h3 y2c ff2 fs0 fc0 sc0 ls0 ws0">• E.g., using ZP/NZP PT-RS to reduce interference </div><div class="t m0 x9 h3 y2d ff2 fs0 fc0 sc0 ls0 ws0">• Details of UE-specific configuration, e.g., associated with the scheduled MCS and/or </div><div class="t m0 xa h3 y2e ff2 fs0 fc0 sc0 ls0 ws0">BW, the number of scheduled layers, or use dedicated signaling</div><div class="t m0 x9 h3 y2f ff2 fs0 fc0 sc0 ls0 ws0">• Others are not precluded</div><div class="t m0 x8 h3 y30 ff2 fs0 fc0 sc0 ls0 ws0">• FFS whether new RS is introduced or extended DMRS is used for phase tracking</div></div><div class="pi" data-data='{"ctm":[1.611850,0.000000,0.000000,1.611850,0.000000,0.000000]}'></div></div> </body> </html>

<div id="pf2" class="pf w0 h0" data-page-no="2"><div class="pc pc2 w0 h0"><img class="bi x0 y0 w1 h1" alt="" src="https://static.pudn.com/prod/directory_preview_static/627554489221806f9d32de80/bg2.jpg"><div class="c x0 y1 w2 h2"><div class="t m0 x1 h3 y2 ff2 fs0 fc0 sc0 ls0 ws0">In previous meetings, it has been agreed to study the design of phase noise tracking reference symbols</div><div class="t m0 x1 h3 y3 ff2 fs0 fc0 sc0 ls0 ws0">(PTRS), used to estimate and compensate for phase noise related errors. One of the most important design</div><div class="t m0 x1 h3 y31 ff2 fs0 fc0 sc0 ls0 ws0">considerations is the time and frequency density of the PTRS. This is important both with respect to the</div><div class="t m0 x1 h3 y5 ff2 fs0 fc0 sc0 ls0 ws0">processing gain needed and the time variations in the phase noise process. In some of the later sections we</div><div class="t m0 x1 h3 y6 ff2 fs0 fc0 sc0 ls0 ws0">investigate this in a basic SISO setup.</div><div class="t m0 x1 h3 y32 ff2 fs0 fc0 sc0 ls0 ws0">First we present a general discussion about the design aspects of the PTRS are discussed. </div><div class="t m0 x1 h5 y33 ff2 fs2 fc0 sc0 ls0 ws0">3 Discussion</div><div class="t m0 x1 h3 y34 ff2 fs0 fc0 sc0 ls0 ws0">Phase noise introduces both a common phase errors (CPE) on all subcarriers, which lead to a rotation of the</div><div class="t m0 x1 h3 y35 ff2 fs0 fc0 sc0 ls0 ws0">received constellation symbol, as well as inter carrier interference (ICI). In [1], the CPE is observed to</div><div class="t m0 x1 h3 y36 ff2 fs0 fc0 sc0 ls0 ws0">dominate over the ICI introduced by phase noise. Therefore, our discussion will mainly focus on using the</div><div class="t m0 x1 h3 y37 ff2 fs0 fc0 sc0 ls0 ws0">PTRS for CPE estimation. It should also be mentioned that PTRS could also be used for frequency offset</div><div class="t m0 x1 h3 y38 ff2 fs0 fc0 sc0 ls0 ws0">estimation. Furthermore, for PTRS design implications related to DFT-S-OFDM, please refer [2]. The main</div><div class="t m0 x1 h3 y39 ff2 fs0 fc0 sc0 ls0 ws0">conclusion is that for the targeted scenarios for DFT-S-OFDM the need for PTRS is limited.</div><div class="t m0 x1 h3 y3a ff1 fs0 fc0 sc0 ls0 ws0">Proposal 1 Consider to preclude a phase tracking reference signal in the DFT-S-OFDM waveform</div><div class="t m0 x1 h3 y3b ff2 fs0 fc0 sc0 ls0 ws0">In [1], it is observed that lower order modulation is less sensitive to phase errors, as compared to higher</div><div class="t m0 x1 h3 y3c ff2 fs0 fc0 sc0 ls0 ws0">order modulation. It is therefore expected that the problem with CPE will be more pronounced for users in</div><div class="t m0 x1 h3 y3d ff2 fs0 fc0 sc0 ls0 ws0">favourable channel conditions, achieving the high SNR required for higher order modulation. Therefore,</div><div class="t m0 x1 h3 y3e ff2 fs0 fc0 sc0 ls0 ws0">PTRS is not necessarily required to be transmitted to/from all active UEs. From a resource utilization</div><div class="t m0 x1 h3 y3f ff2 fs0 fc0 sc0 ls0 ws0">perspective, it is therefore beneficial to only transmit PTRS when needed. This will reduce overhead for the</div><div class="t m0 x1 h3 y40 ff2 fs0 fc0 sc0 ls0 ws0">UL, and for DL if UE specific PTRS are used, the reduction can either be in terms of more data symbols or</div><div class="t m0 x1 h3 y41 ff2 fs0 fc0 sc0 ls0 ws0">less interference if resources are blanked. </div><div class="t m0 x1 h3 y42 ff1 fs0 fc0 sc0 ls0 ws0">Observation 1 PTRS will mainly be needed for UEs scheduled for higher order modulation,</div><div class="t m0 xe h3 y43 ff1 fs0 fc0 sc0 ls0 ws0">excluding UEs in unfavourable channel conditions. </div><div class="t m0 x1 h3 y44 ff1 fs0 fc0 sc0 ls0 ws0">Observation 2 Transmitting PTRS only when needed may reduce overhead and interference.</div><div class="t m0 x1 h3 y45 ff2 fs0 fc0 sc0 ls0 ws0">From the perspective of PTRS, the UL and DL differs in a distinct way. In the UL, the received signals from</div><div class="t m0 x1 h3 y46 ff2 fs0 fc0 sc0 ls0 ws0">different UEs are effected by individual phase noise processes. The different UEs are therefore required to</div><div class="t m0 x1 h3 y47 ff2 fs0 fc0 sc0 ls0 ws0">transmit independent PTRS. For the DL, the PTRS can potentially be shared between all UEs being served</div><div class="t m0 x1 h3 y48 ff2 fs0 fc0 sc0 ls0 ws0">by a single TRP. This may be beneficial from a resource utilization perspective, since resources are shared</div><div class="t m0 x1 h3 y49 ff2 fs0 fc0 sc0 ls0 ws0">amongst UEs. Furthermore, if designed properly, the PTRS could be used for granular phase noise tracking</div><div class="t m0 x1 h3 y4a ff2 fs0 fc0 sc0 ls0 ws0">used for ISI mitigation. On the other hand, since all UEs are targeted with the PTRS, UE specific</div><div class="t m0 x1 h3 y4b ff2 fs0 fc0 sc0 ls0 ws0">beamforming cannot be used, thus reducing the coverage of the signal, unless other means are taken. This</div><div class="t m0 x1 h3 y4c ff2 fs0 fc0 sc0 ls0 ws0">type of signal also increases to the inter-site interference as it needs to be transmitted when it is needed by</div><div class="t m0 x1 h3 y4d ff2 fs0 fc0 sc0 ls0 ws0">some user and will thus not scale well with load. Further on, a shared PTRS also introduces an asymmetry in</div><div class="t m0 x1 h3 y4e ff2 fs0 fc0 sc0 ls0 ws0">the design of the UL and DL. An alternative is instead to schedule UE specific PTRS, which allows for</div><div class="t m0 x1 h3 y4f ff2 fs0 fc0 sc0 ls0 ws0">beamforming and thus providing improved coverage. </div><div class="t m0 x1 h3 y50 ff1 fs0 fc0 sc0 ls0 ws0">Observation 3 For DL, the PTRS can either be shared or UE specific, both having a number of</div><div class="t m0 xe h3 y51 ff1 fs0 fc0 sc0 ls0 ws0">implications requiring further study. </div><div class="t m0 x1 h3 y52 ff2 fs0 fc0 sc0 ls0 ws0">In the following subsection, discussions on the implications of UE specific PTRS in UL and DL is discussed. </div><div class="t m0 x1 h7 y53 ff2 fs4 fc0 sc0 ls0 ws0">3.1 Design considerations for UL PTRS and UE specific PTRS in </div><div class="t m0 xf h7 yf ff2 fs4 fc0 sc0 ls0 ws0">DL</div><div class="t m0 x1 h3 y54 ff2 fs0 fc0 sc0 ls0 ws0">The PTRS can either be a standalone signal, or being co-scheduled with a DMRS. Irrespective of the</div><div class="t m0 x1 h3 y55 ff2 fs0 fc0 sc0 ls0 ws0">approach taken, due to the short coherence time of the phase noise, PTRS may needed to be transmitted on</div><div class="t m0 x6 h6 y13 ff3 fs3 fc0 sc0 ls0 ws0">2/10</div></div><a class="l" rel='nofollow' onclick='return false;'><div class="d m1"></div></a><a class="l" rel='nofollow' onclick='return false;'><div class="d m1"></div></a><a class="l" rel='nofollow' onclick='return false;'><div class="d m1"></div></a></div><div class="pi" data-data='{"ctm":[1.611850,0.000000,0.000000,1.611850,0.000000,0.000000]}'></div></div>