Chin-Feng Lin

A Chaos Base Visual Encryption Mechanism in ECG Medical Signal

In this article, we have developed a chaos base visual encryption mechanism which can be applied in the electrocardiogram (ECG) medical signal. A main idea for using chaos sequence is to increase the un-predication compared with other kind of random sequences. Thus, we based on a values mapping of 1D chaotic scrambler and a permutation scheme to achieve ECG visual encryption. A way to realize the visual encryption mechanism is to scramble the signal values of the input ECG signal by multiplying 1D chaotic signal to randomize ECG signal values, and then a chaotic address scanning order encryption is applied to the randomize reference values. Simulation results show when correct deciphering parameters are put in, the signal will be completely recovered, and the mean square error value e is 1.5849×10−29. As long as there is an input parameter error, for example, with 0.00000001% initial point error, it could make chaotic array, and the ECG medical signal will not be recovered back.

A Chaos-based Visual Encryption Mechanism in Integrated ECG/EEG Medical Signals

In this paper, we have developed a chaos-based visual encryption mechanism which can be applied in the integrated electrocardiogram (ECG)/electroencephalography (EEG) medical signals. A main idea for using chaos sequence is to increase the un-predication compared with other kind of random sequences. Thus, we based on a values mapping of ID chaotic scrambler and a permutation scheme to achieve integrated ECG/EEG visual encryption. A way to realize the visual encryption mechanism is to scramble the signal values of the input integrated ECG/EEG signal by multiplying ID chaotic signal to randomize integrated ECG/EEG signal values, and then a chaotic address scanning order encryption is applied to the randomize reference values. Simulation results show when correct deciphering parameters are put in, the signal will be completely recovered, and the percent root-mean-square difference (PRD) values are 4.69 times 10-15 % and 4.33 times 10-15 % for ECG and EEG medical signals, respectively. As long as there is an input parameter error, for example, with 0.00000001% initial point error, it could make chaotic array, and the ECG and EEG medical signals will not be recovered back.

Downlink power control in multi-code CDMA for mobile medicine

In this paper, we propose a downlink power-control mechanism to be applied in a multi-code code division multiple access (CDMA) mobile medicine system. The mobile medicine system can provide (i) measured blood pressure and body temperature, (ii) medical signals measured by the electrocardiogram (ECG) device, (iii) mobile patient’s history, (iv) G.729 audio signals, (v) Joint Photographic Experts Group 2000 Medical images and Moving Picture Experts Group 4 charge-coupled device sensor video signals. By utilizing a multi-code CDMA spread spectrum communication system with downlink power-control strategy, it is possible for this system to meet the quality of service requirements of a mobile medicine network. In addition, such a system can maximize the resource utilization. For different messages to be sent, the power is controlled according to the requisite bit error rate (BER). Higher transmission power is given to the media with lower BER requirement. Numerical analysis shows that the ratios of transmission power for voice, video, and data virtual channels is approximately 1:2:13 when the BERs for voice, video, and data are 10∧(− 3), 10∧(− 4), and 10∧(− 7), respectively. This power ratio is similar to the ratio of signal-to-noise plus interference power ratio for voice, video, and data during transmission. For the purpose of verifying the proposed argument, a simulation has been done and the results match the derivation very well.

A Chaos Based Unequal Encryption Mechanism in Mobile Medicine System

In this paper, we propose a chaos base unequal encryption mechanism for which can apply in mobile medicine system. A main idea for using chaos sequence is to increase the un- predication compared with other kind of random sequences. In addition, an essential feature of this unequal encryption scheme is that a bit stream mapping of ID chaotic scrambler and a permutation scheme are allocated to the medical information that requires higher level encryption. In contrast, a bit stream mapping of ID chaotic scrambler are granted to messages that can tolerate low level encryption but meet high speed encryption. Simulation results show when correct deciphering parameters are put in, the signal will be completely recovered. As long as there is an input parameter error, for example, with 0.00000001% initial point error, it could make chaotic array, and the encrypted signals will not be recovered back.

Frequency-domain channel estimation for nonlinear multicarrier underwater communication systems

Underwater acoustic (UWA) communications have drawn attention to many researchers in recent years. The major obstacles to reliable UWA communications include limited bandwidth, long multipath delay and large Doppler shifts of the UWA channel. Due to the hostile UWA environment, implementation of a high-speed UWA communication system often requires advanced modulation and signal processing techniques. The multicarrier modulation in the form of orthogonal frequency-division multiplexing (OFDM) has many attractive features which make it a potential candidate for UWA communications. However, the OFDM signal has a high peak-to-average-power ratio (PAPR) and hence is highly susceptible to nonlinearities in the communication link. For combating channel nonlinearities, knowledge of the nonlinear channel is essential. In this paper, we propose a novel method for the estimation of nonlinear channels in OFDM UWA communications. Compared to conventional methods, the proposed method requires a significantly smaller amount of data to achieve the channel estimation. This makes the proposed method suitable for time-varying UWA channels. The effectiveness of the proposed method is demonstrated by applying it to estimate the nonlinear channel of a simulated OFDM UWA communication system.

A Ka Band WCDMA-based LEO Multi-satellites Mobile Medicine System

In this paper, we propose a Ka band wideband code division multiple access (WCDMA) based low earth orbit (LEO) multi-satellites mobile medicine system. An essential feature of this system is that high power, the STBC strategy, more capable error protection schemes, and low level modulation are allocated to the medical information that requires higher quality of service (QoS). In contrast, low power, DM strategy, less capable error protection schemes, and high level modulation are granted to messages that can tolerate high bit error rate (BER). Simulation results show that the proposed scheme can not only fulfill the QoS required by a medicine system, but also achieve the mission of maximum transmission bit rates or minimum transmission power. In addition, by using channel estimation in the proposed system, the Ka band rain fading effect can be mitigated well.

Design of a downlink power control scheme in multi-code CDMA mobile medicine system

In this paper, we proposed a downlink power control scheme to apply in the multi-code CDMA mobile medicine system. The mobile medicine system contains: (i) blood pressure and body temperature measurement value, (ii) medical signals measured by the electrocardiogram device, (iii) mobile patients history, (iv) G.729 audio signal and MPEG-4 CCD sensor video signal. By the help of the multi-code CDMA spread spectrum communication system with downlink power control strategy to make it possible for transmission media in this system to meet the quality of service of mobile medicine system, and achieve the purpose of the maximum resource utilization. In different media, the power is controlled according to the demand for bit error rate. Higher transmission power is given to the media requesting lower bit error rate. Numerical analysis shows that the ratio of transmission power of voice, video and data virtual channels are approximately 1:2:13 when the bit error rates for the voice, video and data are set at 10/sup -3/, 10/sup -4/ and 10/sup -7/. It is similar to the ratio of SNIR of voice, video and data transmission requirement. Meanwhile, we also test related mobile medical signal transmission and simulation.

MIMO GS OVSF/OFDM Based Underwater Acoustic Multimedia Communication Scheme

An underwater acoustic multimedia communication (UWAMC) system is proposed with 2400 transmission modes according to time-varying multipath underwater acoustic (UWA) channel conditions. The orthogonal variable spreading factor (OVSF) scheme and Gold sequence (GS) scramble code are integrated into multi-input multi-output UWAMC system based on orthogonal frequency-division multiplexing to achieve the quality of service of multimedia transmission in the UWA channel. Binary phase shift keying (BPSK) and quadrature phase shift keying (QPSK) adaptive modulation, direct mapping (DM) or space–time block code (STBC) transmission strategies, convolution channel code with rate 1/2 and 1/3, and a power assignment mechanism were adopted in the proposed system. Simulation results show that the bit error rate (BER) and power saving ratio (PSR) performance of the STBC strategy with transmission diversity is superior to that of the DM strategy without transmission diversity, and the performance of the BERs and PSRs of the transmission scheme with the GS scramble code surpasses that of the scheme without the code. The performance of the BERs and PSRs of BPSK modulation with a channel code rate of 1/3 is better than that of BPSK modulation with a channel code rate of 1/2, and the performances of BERs and PSRs of BPSK modulation with a channel code rate of 1/3 are better than that of QPSK modulation with a channel code rate of 1/3. As the length of the OVSF codes increases, the UWAMC system’s BERs decrease, and its PSRs increase. The UWAMC system can achieve either maximum transmission speed or maximum transmission power efficiency.

FBMC/LDPC-BASED UNDERWATER TRANSCEIVER ARCHITECTURE FOR VOICE AND IMAGE TRANSMISSION

This paper proposes a filter bank multicarrier (FBMC)-based underwater transmission scheme for voice and image signals. In this scheme, FBMC transmission technology, low-density parity-check (LDPC) channel coding, adaptive binary phase shift keying (BPSK) modulation or offset quadrature amplitude modulation (OQAM), and a power assignment mechanism are integrated into an underwater voice and image transmission system. The bit error rates (BERs) of voice and image signals for underwater transmission are required to be less than 10^(-3), and 10^(-4), respectively. The BER performances of the proposed scheme in an underwater acoustic channel were demonstrated through simulations, and the power saving ratios for the underwater transmissions of voice and image signals were explored. The simulation results show that the proposed underwater transmission system can achieve a lower transmission-power consumption or a higher transmission data rates compared to a system without the power assignment mechanism. The results also indicate that the proposed system can be used for advanced underwater signal transmissions.

IMF Features of BCI FP1 EEG Signal Using EMD Methods for Cerebral Palsy

In the paper, the intrinsic mode function (IMF) features of Brain-computer interfaces (BCI) FP1 electroencephalogram (EEG) signals for cerebral palsy (CP) using empirical mode decomposition (EMD) methods were analyzed. The BCI FP1 EEG signals for CP and health, were decomposed into nine IMFs and one residual function (RF), respectively. \( IMFERTE_{6} \), \( IMFERTE_{7} \), and \( IMFERTE_{RF} \) of the FP1 signals of CP were 34.36, 32.29, and 18.04%, respectively. \( IMFERTE_{4} \), \( IMFERTE_{5} \), \( IMFERTE_{9} \), and \( IMFERTE_{RF} \) of the BCI FP1 signals of health were 17.93, 16.53, 12.45, and 41.20%, respectively. From the analysis of results, we find that IMF6, IMF7, and RF were the important IMFs of the BCI FP1 EEG signal of CP and IMF4, IMF5, IMF9, and RF were the important IMFs of BCI FP1 EEG signal of health.