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PROPAGATION PATH ESTIMATION METHOD

Foreign code F180009633
File No. 5289
Posted date Nov 20, 2018
Country WIPO
International application number 2016JP005145
International publication number WO 2017104139
Date of international filing Dec 15, 2016
Date of international publication Jun 22, 2017
Priority data
  • P2015-245290 (Dec 16, 2015) JP
Title PROPAGATION PATH ESTIMATION METHOD
Abstract Provided is a propagation path estimation method in which: the in-phase component and quadrature component of a propagation path estimation value for each pilot sub carrier are divided into an amplitude component and a phase component; the propagation path of a data sub-carrier portion existing between the pilot sub-carriers is estimated by phase-amplitude-separated linear interpolation using the separated amplitude component and phase component, respectively; a reference parameter is generated by performing linear interpolation between the pilot sub-carriers on a complex plane; if the quadrants, on a complex plane, of the interpolated phase component estimation value and the reference parameter are different, phase connection processing is performed to resolve phase discontinuity in respect to the interpolated phase component estimation value due to the phase-amplitude-separated linear interpolation; and if the quadrants are not different, or after phase connection processing has been performed, a complex propagation path estimation value of the data sub-carrier portion is calculated from the phase component and the amplitude component of the propagation path estimation value.
Outline of related art and contending technology BACKGROUND ART
Very harsh fading propagation path in the propagation path estimation error with the pilot signal is increased and a problem that the reception quality deteriorates. Wireless communications transmitted in the radio wave reflected by the various propagation environments, scattering, diffraction and received. Through a variety of fading and interference of the radio propagation path received power and the phenomenon of variation is possible, due to the change in the propagation path fluctuates in the case where particularly a high speed or the like and has a severe time-varying.
In addition, a long delay in the propagation environment with a wide band communication is not performed, phase and frequency of the delay amount difference is generated is weakened is strengthened. This is referred to as the frequency selectivity of fading, the delay time of each delayed wave is dependent on the relative power and the intensity difference. Long distance communication is carried out of the delayed wave maximum delay time becomes longer, in particular the frequency selectivity is high.
In such an environment a relatively high efficiency and the communication can be performed in a manner that is known as a modulation scheme OFDM(Orthogonal Frequency Division Multiplex). In this method, orthogonal to each other and not interfere with a plurality of frequency sub-carrier is mounted on the information symbols represented by complex numbers, each of the subcarriers in the time axis signal by adding one OFDM symbol is produced. This operation is typically one OFDM symbol of frequency sub-carriers included in the complex information symbols subjected to inverse Fourier transformation can be realized by performing an operation.
As described above, the influence of fading on the receiver side in order to reach into a digital signal, in order to perform correct demodulation properly influence of this fading propagation path estimation can be performed in each sub-carrier needs to be compensated (equalized). In general each of the sub-carrier bandwidth, sub-carriers in the frequency selectivity of the negligibly small for set, the frequency selectivity between subcarriers by taking into account only the compensation becomes possible.
OFDM is employed in typical communication system or systems such as LTE(Long Term Evolution) WiMAX(Worldwide Interoperability for Microwave Access), both the transmitter and the receiver part of the subcarriers and pilot subcarriers in the known signals, data transmission using the remaining sub-carriers adopted in the method of performing.
In these systems in general and propagation path estimation of the pilot subcarriers, the estimated value of the data subcarriers based on propagation path estimation is carried out, equalization is performed. To perform channel estimation of pilot subcarriers from the estimate of the time, in the prior art method of performing linear interpolation on a complex plane has been used generally. Non-Patent Document 1 is for example, of a general OFDM propagation path estimation method will be described. Non-Patent Document 2 is, in a WiMAX UL channel estimation by linear interpolation of the described method will be explained.
Further, in recent years, from the analog broadcast and digital broadcasting has shifted, a part of the VHF band (hereinafter referred to as 200MHz band) 170MHz-202.5MHz June 2007 by the National Advisory Council for the communication professional is assigned to broadband communication and, when the reference technique has been developed. This technique the reference corresponding to the transmitter as a standard, ARIB STD-T103 developed by has been completed. This is the operation mode of the STD-T103 is two, one of which is known in the WiMAX IEEE 802.16-2009'3' VHF band of the basic parameter Mode1 and is applied to it, the receiver configuration of the mobile communication environment to evaluate the characteristics in the VHF band has been proposed and has heretofore been performed (see Non-Patent Document 3).
Scope of claims (In Japanese)請求の範囲 [請求項1]
 OFDM信号に挿入されたパイロットサブキャリアを使用する伝搬路推定方法において、
 各パイロットサブキャリアにおける伝搬路推定値の同相成分及び直交成分を振幅成分と位相成分に分離し、各パイロットサブキャリア間に存在するデータサブキャリア部分の伝搬路を、この分離された振幅成分及び位相成分それぞれで位相・振幅分離線形補間することによって推定し、
 各パイロットサブキャリア間を複素平面上で線形補間を行うことによって、各パイロットサブキャリア間のデータサブキャリア部分の伝搬路推定を補助するための参照パラメータを生成し、
 上記位相・振幅分離線形補間によって補間された位相成分推定値と上記参照パラメータの複素平面上での象限が異なっているかどうかを判定し、
 象限が異なっていると判定される場合に、上記位相・振幅分離線形補間によって補間された位相成分推定値に対して位相の不連続を解消する位相接続の処理を行い、
 象限が異なっていないと判定される場合、又は上記位相接続処理の後に、各パイロットサブキャリア間の補間されたデータサブキャリア部分の伝搬路推定値の位相成分と振幅成分から当該データサブキャリア部分の複素伝搬路推定値を計算する
 伝搬路推定方法。

[請求項2]
 上記パイロットサブキャリアは、OFDM信号のシンボル方向及びサブキャリア方向でそれぞれ所定の間隔で、もしくは所定の位置に配置される請求項1に記載の伝搬路推定方法。

  • Applicant
  • ※All designated countries except for US in the data before July 2012
  • KYOTO UNIVERSITY
  • Inventor
  • HARADA, Hiroshi
  • MIZUTANI, Keiichi
  • MAKINO, Kiminobu
IPC(International Patent Classification)
Specified countries National States: AE AG AL AM AO AT AU AZ BA BB BG BH BN BR BW BY BZ CA CH CL CN CO CR CU CZ DE DJ DK DM DO DZ EC EE EG ES FI GB GD GE GH GM GT HN HR HU ID IL IN IR IS KE KG KH KN KP KR KW KZ LA LC LK LR LS LU LY MA MD ME MG MK MN MW MX MY MZ NA NG NI NO NZ OM PA PE PG PH PL PT QA RO RS RU RW SA SC SD SE SG SK SL SM ST SV SY TH TJ TM TN TR TT TZ UA UG US UZ VC VN ZA ZM ZW
ARIPO: BW GH GM KE LR LS MW MZ NA RW SD SL SZ TZ UG ZM ZW
EAPO: AM AZ BY KG KZ RU TJ TM
EPO: AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR
OAPI: BF BJ CF CG CI CM GA GN GQ GW KM ML MR NE SN ST TD TG
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