• 한국멀티미디어학회논문지
• /
• 제18권12호
• /
• pp.1547-1554
• /
• 2015

Because there are numerous near field communication (NFC) technical standards and each standard has an independent communication protocol, an NFC software for controlling the protocols are significantly complicated. Especially, the anticollision algorithm for establishing the initial communication connection is classified into bit-oriented or time slot method according to the technical standards. Moreover, the anticollision algorithm is generally manipulated in software because of its complexity. In addition, since one host processor is shared by multiple modems in a connectivity SoC, embedding several communication modems with an NFC modem, the spare computing resources can be utilized for other modems by reducing the software cost to control the NFC modem. In this paper, we propose new design methods of the NFC modem for supporting anticollision, framing and bit rate detection in the hardware to reduce the software overhead. Therefore, the utilization of the NFC technology is enhanced in the connectivity SoC by minimizing the cost of software.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2002년도 ITC-CSCC -1
• /
• pp.560-563
• /
• 2002

This paper proposes a home control system architecture that have network configuration function. The proposed home control system architecture is implemented with partly hardware and software. For implementation of this system architecture, we developed ECONICS which is home automation controller. ECONICS consists of main board and communication modem. This communication modem supply the power line communication. The physical layer and the MAC layer software of EIA 709.1 standard protocol are implemented in communication modem. The upper layer software of EIA 709.1 standard protocol and home configuration software for home network installation, management, diagnostics, control and monitoring are implemented in main board of ECONICS. We verified the commercial feasibility of the proposed system through the home network configuration and operation. As a result, we have concluded that the proposed home control system architecture provides all the key function necessary to easily manage and control home network nodes.

• 한국마린엔지니어링학회:학술대회논문집
• /
• 한국마린엔지니어링학회 2006년도 전기학술대회논문집
• /
• pp.109-110
• /
• 2006

The performance of a digital baseband signal processing and data transmission rate depends on the modulation technique. In this paper, We implemented DSP communication system for Underwater acoustic communication using by adaptive BPSK modem technique. In order to implement adaptive modem, we suggested SNR detection block. SNR detection block has the reference SNR value that selects between window filter path and matched filter path. In this paper, suggested system is based on software interface and all Hardware(PLL, modem filter, equalizer etc) is implemented by software, exclusive of DSP, A/D, D/A converter, SDRAM and Flash memory.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2002년도 ITC-CSCC -3
• /
• pp.1428-1431
• /
• 2002

It is general opinion that the future mobile multimedia networks will use different standards and a prospective solution to this problem will be software defined radio (SDR) techniques. SDR provides the flexibility to support multiple air interfaces and signal processing functions at the same time. Especially, digital signal processors and FPGAs are widely used for implementation of these adaptive and flexible functions of a baseband modem for SDR applications. Also, it is known that the modulation schemes of OCQPSK (Orthogonal Complex QPSK) and HPSK (Hybrid PSK) are used for IMT-2000 services of cdma2000 and WCDMA, respectively. Thus, in this paper, we design and implement an OCQPSK / HPSK modem using a DSP chip of Texas Instrument's TMS320C6701. One modulation scheme is operated by adaptive selection between the two schemes and 5 physical traffic channels differentiated by orthogonal codes are implemented in one DSP chip and each channel has 1Mbps data rates and 8Mcps chip rates.

• 디지털산업정보학회논문지
• /
• 제8권1호
• /
• pp.117-123
• /
• 2012

This paper implements mobile Worldwide Interoperability for Microwave Access (WiMAX) receiver using Software Defined Radio (SDR) technology. SDR system is difficult to implement on the mobile handset because of restrictions that are computing power and under space constraints. The implemented receiver processes mobile WiMAX software modem on Open Multimedia Application Platform (OMAP) System on Chip (SoC) and Field Programmable Gate Array (FPGA). OMAP SoC is composed of ARM processor and Digital Signal Processor (DSP). ARM processor supports Single Instruction Multiple Data (SIMD) instruction which could operate on a vector of data with a single instruction and DSP is powerful image and video accelerators. For this reason, we suggest the possibility of SDR technology in the mobile handset. In order to verify the performance of the mobile WiMAX receiver, we measure the software modem runtime respectively. The experimental results show that the proposed receiver is able to do real-time signal processing.

• 디지털산업정보학회논문지
• /
• 제9권2호
• /
• pp.81-87
• /
• 2013

In this paper, we present an implementation of Long Term Evolution (LTE) Uplink (UL) system on a Software Defined Radio (SDR) platform using a conventional Personal Computer (PC), which adopts Graphic Processing Units (GPU) and Universal Software Radio Peripheral2 (USRP2) with URSP Hardware Driver (UHD) for SDR software modem and Radio Frequency (RF) transceiver, respectively. We have adopted UHD because UHD provides flexibility in the design of transceiver chain. Also, Cognitive Radio (CR) engine have been implemented by using libraries from UHD. Meanwhile, we have implemented the software modem in our system on GPU which is suitable for parallel computing due to its powerful Arithmetic and Logic Units (ALUs). From our experiment tests, we have measured the total processing time for a single frame of both transmit and receive LTE UL data to find that it takes about 5.00ms and 6.78ms for transmit and receive, respectively. It particularly means that the implemented system is capable of real-time processing of all the baseband signal processing algorithms required for LTE UL system.

• 한국항행학회논문지
• /
• 제16권2호
• /
• pp.351-359
• /
• 2012

본 논문에서는 CDMA 데이터 모뎀을 이용하여 원격에서 다양한 입출력 장치들의 상태를 계측하거나 이들을 제어하는 시스템을 설계하고 개발한다. 그리고 TCP/IP 패킷 통신과 단문자서비스(SMS) 통신방식을 이용하여 공인 IP 주소를 갖지 않는 CDMA 모뎀 장치들을 위한 양방항 데이터 통신 방식을 제안한다. 설계된 원격 제어 및 계측시스템은 DCE로 Telit WM-800 모뎀과 DTE로서 Atmel AT89C51 마이크로컨트롤러를 사용하여 구현되었다. 제어 및 계측 시스템 사용자를 위한 사용자 응용 프로그램, 그리고 디지틀 입출력 장치, AD/DAC, LCD, 및 온습도 센서 등의 펌웨어 구동장치 프로그램은 보다 다양한 종류의 응용을 위하여 각각 Microsoft C 및 Keil C 언어를 사용하여 작성되었다. 본 논문에서 구현된 제어 및 계측 시스템의 실험결과는 실제 실시간 실험을 통해, 설계된 바와 같이 사용자가 원하는 동작을 정확하게 수행하는 것을 확인하였다.

• 한국전자파학회논문지
• /
• 제12권5호
• /
• pp.817-826
• /
• 2001

본 논문에서는 TI(Texas instrument)사의 범용 DSP 프로세서인 TMS320C31을 이용하여 통신 시스템에서 많이 사용되는 QPSK 방식의 모뎀을 구현하였다. 지금까지 거의 모든 시스템의 신호 변환 과정은 하드웨어로 구성되어 있지만, 본 논문에서 구현된 시스템은 QPSK 신호의 변조과정에서 IF단의 DAC를 통과하기 이전까지의 과정과 복조과정에서 IF단의 ADC를 통과한 이후의 과정을 프로그램으로 구성하고, 신호의 입.출력부와 처리부분을 하드웨어로 구성하였다. DSP 프로세서를 이용한 모뎀 출력 결과를 PC 상에서 시뮬레이션 결과와 비교하여 제작한 모뎀이 정상적으로 동작됨을 확인하였다.

• 전자공학회논문지A
• /
• 제33A권6호
• /
• pp.220-229
• /
• 1996

We presetn sytem-level simulation methodology as well as environment setup established for CDMA digtial cellular mobile station in an effort to verify CDMA modem ASIC design. To make the system-level simulation feasible, behavioral modeling of a microcontroller was first carried out with VHDL. In addition, models written in C language were also developed to provide ASIC with realistic input data. Finally, the netlist of CDMA modem ASIC was loaded on the a hardware accelerator, which was interfaced with VHDL simulator, and ismulation was performed by excuting the actual CDMA call processing software. Simulation resutls thus obtained were confirmed by comparing them with the emulation resutls from the actual system constructed on hardware modeler. these methods were proved to be effective in both discovering in advance malfunctions when embedded in the system or design errors of ASIC and reducing simulation time by a factor of as much as 20 in case of simulation at gate-level.

• 한국군사과학기술학회지
• /
• 제18권4호
• /
• pp.423-431
• /
• 2015

A leased line modem usability was evaluated and investigated in the wireless internet protocol(IP) network. The signal of the modem in the circuit switching network was translated to IP packet by using several voice codecs (PCM, G.711A, $G.711{\mu}$, and etc.) and transmitted through the wireless IP network. The wireless IP network was simulated by the Tactical information and communication network Modeling and simulation Software(TMS). The performance and usability of the leased line modem are simulated using the system-in-the-loop(SITL) function of TMS with respect to packet delay, jitter, packet discard ratio, codecs, and wireless link BER.