Presentation 2020-11-25
Deep Learning Aided Channel Estimation for Massive MIMO with Pilot Contamination
Hiroki Hirose, Tomoaki Ohtsuki,
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Abstract(in Japanese) (See Japanese page)
Abstract(in English) In a time division duplex (TDD) based massive multiple-input multiple-output (MIMO) system, a base station (BS) needs accurate estimation of channel state information (CSI) for a user terminal (UT). Due to the time-varying nature of the channel, the length of pilot signals is limited and the number of orthogonal pilot signals is finite. Hence, the same pilot signals are required to be reused in neighboring cells and thus its channel estimation performance is deteriorated by pilot contamination from the neighboring cells. With the minimum mean square error (MMSE) channel estimation, the influence of pilot contamination can be reduced by the fully known covariance matrix of channels for all the UTs using the same pilot signal. However, this matrix is unknown to the BS a priori, and has to be estimated. In this report, we propose two methods of deep learning aided channel estimation to reduce the influence of pilot contamination. One method uses a neural network consisting of fully connected layers, while the other method uses a convolutional neural network (CNN). The neural network, particularly the CNN, plays a role in extracting features of the spatial information from the contaminated signals. In terms of the speed of training, the former method is better than the latter one. We evaluate the proposed methods under two scenarios, i.e., perfect timing synchronization and imperfect one. Simulation results confirm that the proposed methods are better than the LS and the covariance estimation method via normalized mean square error (NMSE) of the channel.
Keyword(in Japanese) (See Japanese page)
Keyword(in English) Massive MIMO / Pilot contamination / Channel estimation / Deep learning
Paper # RCS2020-110
Date of Issue 2020-11-18 (RCS)

Conference Information
Committee RCS / AP
Conference Date 2020/11/25(3days)
Place (in Japanese) (See Japanese page)
Place (in English) Online
Topics (in Japanese) (See Japanese page)
Topics (in English) Adaptive Antenna, Equalization, Interference Canceler, MIMO, Wireless Communications, etc.
Chair Eiji Okamoto(Nagoya Inst. of Tech.) / Qiang Chen(Tohoku Univ.)
Vice Chair Fumiaki Maehara(Waseda Univ.) / Toshihiko Nishimura(Hokkaido Univ.) / Tomoya Tandai(Toshiba) / Satoru Kurokawa(AIST)
Secretary Fumiaki Maehara(Kyushu Univ.) / Toshihiko Nishimura(NEC) / Tomoya Tandai(Tokyo Univ. of Agric. & Tech.) / Satoru Kurokawa(NTT DOCOMO)
Assistant Koichi Adachi(Univ. of Electro-Comm.) / Osamu Nakamura(Sharp) / Manabu Sakai(Mitsubishi Electric) / Masashi Iwabuchi(NTT) / Tatsuki Okuyama(NTT DOCOMO) / Dr. Kim(Niigata Univ.)

Paper Information
Registration To Technical Committee on Radio Communication Systems / Technical Committee on Antennas and Propagation
Language JPN
Title (in Japanese) (See Japanese page)
Sub Title (in Japanese) (See Japanese page)
Title (in English) Deep Learning Aided Channel Estimation for Massive MIMO with Pilot Contamination
Sub Title (in English)
Keyword(1) Massive MIMO
Keyword(2) Pilot contamination
Keyword(3) Channel estimation
Keyword(4) Deep learning
1st Author's Name Hiroki Hirose
1st Author's Affiliation Keio University(Keio Univ.)
2nd Author's Name Tomoaki Ohtsuki
2nd Author's Affiliation Keio University(Keio Univ.)
Date 2020-11-25
Paper # RCS2020-110
Volume (vol) vol.120
Number (no) RCS-249
Page pp.pp.1-6(RCS),
#Pages 6
Date of Issue 2020-11-18 (RCS)