Satoshi Suyama

• Doctor of Engineering
• NTT DOCOMO

This paper proposes iterative decision feedback channel estimation (IDFCE) using a time-division multiplexing based reference signal that is incorporated into a turbo frequency-domain equalizer (FDE) for discrete Fourier transform (DFT)-Spread Orthogonal Frequency Division Multiplexing (OFDM) (DFT-S-OFDM hereafter). In the proposed IDFCE, estimated...

This paper proposes physical random access channel (PRACH) transmission employing carrier frequency offset (CFO) pre-compensation that is measured at a set of user equipment (UE) using the synchronization signal block for the New Radio uplink. Computer simulation results show that by using cyclic-prefix (CP)-based fractional-frequency offset (FFO)...

This paper presents the physical layer cell identity (Polo) detection probability using polarization receiver diversity based on the primary synchronization signal (PSS) and secondary synchronization signal (SSS) of the New Radio (NR) interface for 3GPP Clustered Delay Line (CDL) channel models. We first validate the POD detection probability in th...

This paper presents the detection performance of New Radio (NR) downlink initial access in the physical layer including physical-layer cell ID (PCID) detection, detection of the demodulation reference signal (DMRS) in the physical broadcast channel (PBCH), and demodulation and decoding of the PBCH payload using the synchronization signal block (SSB...

The sixth generation (6G) wireless communication system requires extreme capacity and coverage, which can be achieved through the introduction of higher frequency and ultra-large-scale reconfigurable intelligent surface (RIS) array. This also enables the expansion of the near-field range to tens or even hundreds of meters. However, near-field beamf...

In this letter, a method for path loss prediction in outdoor urban environments based on computer graphics technologies is presented. Each wall of buildings in an evaluation area is assigned to a different RGB color. We create two types of color images that are viewed from a transmission point (Tx) and receiving points (Rxs). By analyzing and compa...

The 6th generation mobile networks require large bandwidth on sub-Terahertz bands to provide more than 100 Gbps throughput. To provide enough beamforming gain to combat the path loss on high-frequency bands, large-scale antenna arrays should be used, which generate narrow and directive beams. It may require hundreds or thousands of beams to cover a...

Reconfigurable intelligent surface (RIS) is a research hotspot for the fifth generation evolution (5GE) and the sixth generation (6G) wireless communication systems to extend high-frequency coverage. Due to the increase of the carrier frequency of the wireless communication system and the large scale of the RIS array, the near-field region is signi...

Utilization of THz wave is being considered to achieve the target expected for 6 th Generation Mobile Communication System (6G). The research topics and considerations how to use the bands in 6G era is addressed.

In order to realize the higher bit rates compared for the fifth-generation (5G) mobile communication system, massive MIMO technologies in higher frequency bands with wider bandwidth are being investigated for 5G evolution and 6G. One of practical method to realize massive MIMO in the high frequency bands is hybrid beamforming (BF). With this approa...

In sixth-generation (6G) mobile communication system, it is expected that extreme high data rate communication with a peak data rate over 100 Gbps should be provided by exploiting higher frequency bands in addition to millimeter-wave bands such as 28 GHz. The higher frequency bands are assumed to be millimeter wave and terahertz wave where the extr...

In order to enhance the fifth generation (5G) mobile communication system further toward 5G Evolution, high bit-rate transmission using high SHF bands (28 GHz or EHF bands) should be more stable even in high-mobility environments such as high speed trains. Of particular importance, dynamic changes in the beam direction and the larger Doppler freque...

The fifth-generation (5G) mobile communications system initially introduced massive multiple-input multiple-output (M-MIMO) with analog beamforming (BF) to compensate for the larger path-loss in millimeter-wave (mmW) bands. To solve a coverage issue and support high mobility of the mmW bands, base station (BS) cooperation technologies have been inv...

The super-high-frequency (SHF) band is used in the 5th generation mobile communication system (5G), and the introduction of massive multiple-input multiple-output (MIMO) to 5G is being considered. In an environment with substantial propagation loss, such as that in the case of millimeter waves, massive MIMO can realize beamforming according to the...

We propose a correction formula using the percentage of area occupied by buildings, α, for a path model in the urban macrocell environment defined in ITU-R M.2135 based on measurements performed in Japan for below 6 GHz for 5G. Based on analysis, the regression results of the correction formula in which S, the median of the difference between the m...

In the 5th generation mobile communication system, introduction of small cells using low-height base station is being examined. Small cells are installed in urban street cell environments where mobiles are densely populated. Therefore, actual measurement and complicated modeling of radio wave propagation are necessary to grasp the propagation chara...

For high-density wireless LAN environment, the interference among overlapped basic service sets (OBSSs) is a serious problem. To address this issue, we have proposed distributed smart antenna system (D-SAS) for wireless LAN, which suppresses the interference among OBSSs and improves the throughput. We have also developed the prototype of wireless L...

The field trial results for massive multi-user multiple-input multiple-output (MU-MIMO) transmission at 28 GHz with 500 MHz bandwidth are reported in this paper. In this experiment, hybrid beamforming with block diagonal precoding is employed, in which channel state information is acquired by uplink sounding assuming channel reciprocity in a time d...

In order to cope with recent growth of mobile data traffic and emerging various services, world-wide system trials for the fifth-generation (5G) mobile communication system that dramatically extends capability of the fourth-generation mobile communication system are being performed to launch its commercial service in 2020. In addition, research and...

Fifth-generation mobile communication systems (5G) must offer significantly higher system capacity than 4G in order to accommodate the rapidly increasing mobile data traffic. Cell densification has been considered an effective way to increase system capacity. Unfortunately, each user equipment (UE) will be in line-of-sight to many more transmission...

Field trials of the fifth-generation (5G) mobile communication system using 28 GHz band at which almost 1 GHz bandwidth will be available have been performed all over the world. To realize large coverage with such a high frequency band, beamforming by Massive MIMO (Multiple Input Multiple Output) is necessary to compensate the large path loss. Furt...

The beamforming (BF) provided by Massive MIMO is a promising technique for the fifth-generation (5G) mobile communication system. In low SHF bands such as 3-6 GHz, fully digital Massive MIMO can be a feasible option. Previous works proposed eigenvector zero-forcing (E-ZF) as a digital precoding algorithm to lower the complexity of block diagonaliza...

Towards furthering the industrial revolution, the concept of a new cellular network began to be drawn up around 2010 as the fifth generation (5G) mobile wireless communication system. One of the main differences between the fourth generation (4G) mobile communication system Long Term Evolution (LTE) and 5G new radio (NR) is the frequency bands util...

Massive multiple input and multiple output (Massive MIMO) is a key technique to achieve high system capacity and user data rate for the fifth generation (5G) radio access network (RAN). To implement Massive MIMO in 5G, how much Massive MIMO meets our expectation with various user equipment (UEs) in different environments should be carefully address...

The Ministry of Internal Affairs and Communications of Japan began field trials of fifth-generation mobile communications systems (5G) in fiscal year 2017. This effort is aimed at developing a new market through social implementation of 5G. These Feature Articles explain the results of experimental trials conducted by NTT DOCOMO and NTT Communicati...

In this article, we describe two examples of field trials contracted by the Ministry of Internal Affairs and Communications of Japan concerning application of fifth-generation mobile communications systems (5G). The first example was in the area of smart city/smart area and was focused on providing a safe and secure society. The results of experime...

Experimental trials of use cases of fifth-generation mobile communications systems (5G) in high mobility environments exceeding 90 km/h were carried out as part of the 5G Field Trials initiated by the Ministry of Internal Affairs and Communications of Japan. These trials were conducted to evaluate the transmission and distribution of high-presence,...