• International Journal of Internet, Broadcasting and Communication
• /
• v.12 no.1
• /
• pp.7-13
• /
• 2020

We describes V2X technology, a connectivity-based recognition technology that is attracting attention as a key technology for implementing autonomous driving technology, and autonomous communication modules that implement ADAS technology, a sensor-based recognition technology. It also explains the trends in V2X technology standardization centered on IEEE 802.11p, which is a WAVE technology standard based on Wi-Fi/DSRC. Finally, we will discuss the market growth trend of V2X communication modules in the United States, the leading V2X technology module, and the development of technology development trends of major domestic and international companies that are leading the global technology market related to V2X communication modules. V2X and ADAS technologies will be the biggest influence on automotive purchasing decisions. In recent years, V2I mandates have been promoted beyond V2V, mainly in developed countries such as the United States. The related industry needs to focus on the development of information transmission network technology that can support high frequency high efficiency(transmission rate) and sophisticated positioning accuracy beyond conventional vehicle communication.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.48 no.11
• /
• pp.18-26
• /
• 2011

This paper describes a multi-mode LDPC decoder which supports three block lengths(648, 1296, 1944) and four code rates(1/2, 2/3, 3/4, 5/6) of IEEE 802.11n wireless LAN standard. To minimize hardware complexity, it adopts a block-serial (partially parallel) architecture based on the layered decoding scheme. A novel memory reduction technique devised using the min-sum decoding algorithm reduces the size of check-node memory by 47% as compared to conventional method. From fixed-point modeling and Matlab simulations for various bit-widths, decoding performance and optimal hardware parameters such as fixed-point bit-width are analyzed. The designed LDPC decoder is verified by FPGA implementation, and synthesized with a 0.18-${\mu}m$ CMOS cell library. It has 219,100 gates and 45,036 bits RAM, and the estimated throughput is about 164~212 Mbps at 50 MHz@2.5v.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.43 no.11 s.353
• /
• pp.77-82
• /
• 2006

Analog channel selection filter is described which is designed for a direct-conversion receiver of a IEEE 802.11a wireless LAN. The channel selection filter is an active-RC fifth-order Chebyshev filter with 10MHz cut-off frequency. Two-stage operational amplifier of the filter employs a current re-using feedforward frequency compensation scheme to minimize the power consumption. The filter has been implemented in a 0.18mm CMOS technology and the experimental results show 20mW power consumption with 1.8V supply voltage and 19dB out-of-band iIP3.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.15 no.6
• /
• pp.1355-1362
• /
• 2011

This paper describes a multi-mode LDPC decoder which supports three block lengths(648, 1296, 1944) and four code rates(1/2, 2/3, 3/4, 5/6) of IEEE 802.11n WLAN standard. Our LDPC decoder adopts a block-serial architecture based on min-sum algorithm and layered decoding scheme. A novel way to store check-node values and parity check matrix reduces the sizes of check-node memory and H-ROM. An efficient scheme for check-node memory addressing is used to achieve stall-free read/write operations. The designed LDPC decoder is verified by FPGA implementation, and synthesized with a $0.18-{\mu}m$ CMOS cell library. It has 219,100 gates and 45,036 bits RAM, and the estimated throughput is about 164~212 Mbps at 50 MHz@2.5v.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2011.05a
• /
• pp.132-135
• /
• 2011

This paper describes a multi-mode LDPC decoder which supports three block lengths(648, 1296, 1944) and four code rates(1/2, 2/3, 3/4, 5/6) of IEEE 802.11n WLAN standard. To minimize hardware complexity, it adopts a block-serial (partially parallel) architecture based on the layered decoding scheme. A novel memory reduction technique devised using the min-sum decoding algorithm reduces the size of check-node memory by 47% as compared to conventional method. The designed LDPC decoder is verified by FPGA implementation, and synthesized with a $0.18-{\mu}m$ CMOS cell library. It has 219,100 gates and 45,036 bits RAM, and the estimated throughput is about 164~212 Mbps at 50 MHz@2.5v.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.15 no.1
• /
• pp.95-101
• /
• 2016

Vehicular communications is system which can be applied for transmission of various safety messages or Intelligent Transportation Systems(ITS) applications by combining vehicle/road technology with Information and Communication Technology(ICT). In recent years, a variety of ITS services are available such as driving information, road conditions, V2X messages as well as navigation and traffic jams notification. In general, vehicular communications can be used for vehicle-to-vehicle and vehicle-to-infrastructure communication by adopting IEEE802.11p/1609 standard which is commonly known as wireless access in vehicular environments. In this paper, WAVE communication standard based on the IEEE802.11p is explained and signal characteristics in WAVE communication is introduced. Also, The H/W and S/W characteristics in Road Side Station and On Board Equipment for the Vehicle to Everything communication are analyzed. Received Signal Strength which is power of receiving signal of communication equipment is measured in test road to estimate the real WAVE communication's performance. It is shown that the implemented WAVE communication technology is satisfactory to provide ITS services.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.12 no.3
• /
• pp.96-102
• /
• 2013

In recent years, a variety of ITS services are available such as driving information, road conditions, V2X messages as well as navigation and traffic jams notification. The development of ITS services is accelerating by V2X communication technologies for high-speed vehicles. In this paper, WAVE communication devices based on the IEEE802.11p standard is introduced as a solution of V2X communication technologies. The H/W and S/W structures of the WAVE communication device and the characteristics of RF/antenna are described. The performance is evaluated in the test road by measuring throughput, PER and latency. The implemented WAVE communication device has 6~7 Mbps throughput with 10% PER at 1km coverage. The packet latency is less than 3ms for the whole test road. It is shown that the implemented WAVE technology is satisfactory to provide ITS services and Internet video-streaming services.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.43 no.9 s.351
• /
• pp.17-22
• /
• 2006

CMOS LC VCO with fast response adaptive frequency calibration (AFC) technique for IEEE 802.11a/b/g WLANs is designed in 1.8V $0.18{\mu}m$ CMOS process. The possible operation is verified for 5.8GHz band, 5.2GHz band, and 2.4GHz band using the switchable L-C resonators. To linearize its frequency-voltage gain (Kvco), optimized multiple MOS varactor biasing tecknique is used. In order to operate in each band frequency range with reduced VCO gain, 4-bit digitally controlled switched- capacitor bank is used and a wide-range digital logic quadricorrelator (WDLQ) is implemented for fast frequency detector.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.34 no.5B
• /
• pp.463-468
• /
• 2009

In VANET(Vheicle Ad hoc Network), the researches based on the wireless LAN are conducting and the method based on 802.11a is being adapted in IEEE 802.11p WAVE(Wireless Access in Vehicular Environments). However, wireless LAN which uses a single channel in a competition can cause transmission delays because of a frequent collision and a use of CSMA/CA to avoid competition in VANET requiring a fast access. In this paper, we designed CMMP (Clustering based Multi-channel MAC protocol) adequate to VANET and then confirmed the appropriate channel conditions in a V2V communication on the basis of this protocol. The simulation results showed that a packet collision and a transmission delay by the use of an existing single channel based on the contention decreased more than 60% by CMMP.

• 한국ITS학회:학술대회논문집
• /
• v.2006 no.10
• /
• pp.209-212
• /
• 2006