• Journal of Advanced Navigation Technology
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• v.11 no.4
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• pp.408-414
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• 2007

Research advances in the areas of micro-sensor device and wireless network technology, has made it possible to develop energy efficient and low cost wireless sensor nodes. In this paper, the forward error control (FEC) scheme for lower power consumption and excellent BER(Bit Error Rate) performance during transmission propose in multi-hop wireless sensor network based on FSK modem. The FEC technique uses extra processing power related to encoding and decoding, it is need complex functions to be built into the sensor node. The probability of receiving a correct bit and codeword for relaying a frame over h nodes to the sink node is calculated as a function of channel parameter, number of hops, number of bits transmitted and the distance between the different nodes.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.9
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• pp.936-943
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• 2003

The miniaturized wireless endoscope consists of CMOS Image sensor, FPGA, LED, Battery, DC to DC Converter, Antenna and Transmitter. FSK transmitter is designed and fabricated with 10 mm(diameter)${\times}$23 mm(thickness) dimension considering the maximum permission exposure(MPE), system size, power consumption, linearity and modulation method. Experimental results is - 3.67 dBm output power level, 20 MHz frequency deviation, and - 99 dBc/Hz(@100 kHz offset) phase noise at 1.2 GHz. From the in-vivo experiment, the designed FSK transmitter has a acceptable capability for wireless endoscope.

• Journal of the Korean Institute of Telematics and Electronics
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• v.27 no.10
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• pp.1-9
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• 1990

The performance of noncoherent FH/FSK system in the presence of multitone jamming and noise is analyged. Random and the structured jammings are considered as a multitone jamming model. The probability density function is derived and then optimum decision rule is applied to determine error probability of each cases. As a result, error probabilities of random and structured multitone jamming are shown as a function of number of jamming tones, jamming to signal power ratio, jamming signal phase and one jamming tone power to signal power ratio under Worst-case Jamming interference. It is found that error probability is maximam when one jamming tone power to signal power ratio is 1. Also we know that error performance of random and structured jamming is almost equal.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.1
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• pp.33-40
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• 2011

In this paper, underwater acoustic communication experiment was carried out to test a performance of single carrier digital modulation schemes. The communication experiment was performed at real sea and tested modulation schemes are ASK, FSK with non-coherent detection and QPSK with coherent detection. A modulated image data was transmitted with data rates of 600bps~3Kbps. From the results of BER of the demodulated signal, ASK and FSK show the achievable BER of $10^{-3}{\sim}10^{-4}$ without compensation techniques and QPSK show that of $10^{-4}$ with linear equalizer.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.9
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• pp.1672-1678
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• 2007

The communication systems and characteristics of transmit are very importance a serious view of ubiquitores society. The high rate systems have to construct for data of voice, graphics and moving-video with the multimedia to transmit on the low frequency band. The rate of data are relation that there are the bandwidth of line and channels, the bit per second and communication-systems. This paper study for the error performance of 2, 4 8 level FSK to transmit amount of data in the communication systems and design to FDM system.

• Journal of Industrial Technology
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• v.17
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• pp.153-160
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• 1997

This paper has analyzed the performance against a single tone jamming for the CPM DS-SS system with a Binary FSK Modulation. The CPM DS-SS system designed with the different phase shift of the same pseude-noise code has the advantage of reducing the jamming and interference effects on multi-users communication environment. Analytical results show that the system preformance improves by increasing parrallel users in the presence of the coherent single-tone, which is the worst interference since the jamming signal has the same frequency as a carrier.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.6 no.4
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• pp.3-10
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• 1995

In this paper, application of PTCM to 2FSK / 4PSK signals is studied. The generator polynomial of punctured trellis coded 2FSK / 4PSK, metric computation techniques, decoding complexity considerations are provided. Simulation results shows that PTCM of 2FSK / 4PSK archieves equal coding gain in com- parison to Padovani and Wolf's system with less decoding complexity.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.33A no.10
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• pp.22-27
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• 1996

A digital logic demodulator for binary FSK signals is presented. The operation is based on the quadricorrelator which is known as an ideal frequency detector. The demodulator is especially suitable for high-speed application, and it can be easily implemented in integrated circuit. Computer simulation results show that the performance of the receiver with digital demodulator converges to that of analog quadricorrelator receiver as the number of mixing axes is increased and the optimum bandwidth depending on a modulation index is slightly wider than that of analog demodulator.

• Proceedings of the Optical Society of Korea Conference
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• 1991.06a
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• pp.121-125
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• 1991

A basic coherent optical transmission was demonstrated using FSK modulation and heterodyne detection scheme. Optical frequency of DFB LD light source at the transmitter side was stabilized with Fabry Perot etalon and bias feedback circuit. A tunable external cavity LD was used as a local oscillator at the receiver. Heterodyned output signal at IF frequency of 2GHz was measured and discussed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.16 no.5
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• pp.424-433
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• 1991

In the noncoherent FH/FSK system presence of the multitione jamming and noise, in the case random and 송 structures jamming model, the performance analyzed that random and struetured jamming derived error proability. It is found that error probability and performance when error corecting code used Hamming. BCH, Convolutional code under the worst case partial band jamming interference.