No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Performance evaluation of digital modulation techniques used in Bluetooth physical/radio layer
... Numerous studies have also tackled the inter-dependencies between SNR, BER, and modulation schemes with distance and for different throughput. Reference [101] analyzes the impact of different modulation schemes on BER for Bluetooth with and without FHSS.Reference [103] proposes an algorithm for estimating the SNR based on the power spectrum that can adapt to different Bluetooth packets. Reference [102] analyzes the effects of interference on both BER and throughput. ...
... The new standard for Bluetooth, BLE is discussed inReference [104] in terms of energy consumption for different modulation schemes, emphasizing the importance of energy per bit analysis for selecting the optimal range and rate. As shown and discussed inReferences [101][102][103][104], these inter-dependencies have a great impact on the power consumption of the sensor node with Bluetooth transceiver. The first strategy to obtain a lower BER is to use the lowest rate modulation schemes. ...
Autonomous Wireless Sensors (AWSs) are at the core of every Wireless Sensor Network (WSN). Current AWS technology allows the development of many IoT-based applications, ranging from military to bioengineering and from industry to education. The energy optimization of AWSs depends mainly on: Structural, functional, and application specifications. The holistic design methodology addresses all the factors mentioned above. In this sense, we propose an original solution based on a novel architecture that duplicates the transceivers and also the power source using a hybrid storage system. By identifying the consumption needs of the transceivers, an appropriate methodology for sizing and controlling the power flow for the power source is proposed. The paper emphasizes the fusion between information, communication, and energy consumption of the AWS in terms of spectrum information through a set of transceiver testing scenarios, identifying the main factors that influence the sensor node design and their inter-dependencies. Optimization of the system considers all these factors obtaining an energy efficient AWS, paving the way towards autonomous sensors by adding an energy harvesting element to them.
... Numerous studies have also tackled the inter-dependencies between SNR, BER, and modulation schemes with distance and for different throughput. Reference [101] analyzes the impact of different modulation schemes on BER for Bluetooth with and without FHSS. Reference [102] proposes an algorithm for estimating the SNR based on the power spectrum that can adapt to different Bluetooth packets. ...
... The new standard for Bluetooth, BLE is discussed in Reference [104] in terms of energy consumption for different modulation schemes, emphasizing the importance of energy per bit analysis for selecting the optimal range and rate. As shown and discussed in References [101][102][103][104], these inter-dependencies have a great impact on the power consumption of the sensor node with Bluetooth transceiver. The first strategy to obtain a lower BER is to use the lowest rate modulation schemes. ...
Autonomous Wireless Sensors (AWSs) are at the core of every Wireless Sensor Network (WSN). Current AWS technology allows the development of many IoT-based applications, ranging from military to bioengineering and from industry to education. The energy optimization of AWSs depends mainly on: Structural, functional, and application specifications. The holistic design methodology addresses all the factors mentioned above. In this sense, we propose an original solution based on a novel architecture that duplicates the transceivers and also the power source using a hybrid storage system. By identifying the consumption needs of the transceivers, an appropriate methodology for sizing and controlling the power flow for the power source is proposed. The paper emphasizes the fusion between information, communication, and energy consumption of the AWS in terms of spectrum information through a set of transceiver testing scenarios, identifying the main factors that influence the sensor node design and their inter-dependencies. Optimization of the system considers all these factors obtaining an energy efficient AWS, paving the way towards autonomous sensors by adding an energy harvesting element to them.
This research presents a survey of application of
hyperchaotic map on encryption of color images. There are various
researches that have introduced this application. Among these
papers, one of them has presented a technique for altering and
encoding color images based on S-box based on the hyperchaotic
map foundation and several chaotic maps and an. It has shown its
efficiency against a wide range of cryptographic assaults and has
obtained good results.
This practically-oriented, all-inclusive guide covers all the major enabling techniques for current and next-generation cellular communications and wireless networking systems. Technologies covered include CDMA, OFDM, UWB, turbo and LDPC coding, smart antennas, wireless ad hoc and sensor networks, MIMO, and cognitive radios, providing readers with everything they need to master wireless systems design in a single volume. Uniquely, a detailed introduction to the properties, design, and selection of RF subsystems and antennas is provided, giving readers a clear overview of the whole wireless system. It is also the first textbook to include a complete introduction to speech coders and video coders used in wireless systems. Richly illustrated with over 400 figures, and with a unique emphasis on practical and state-of-the-art techniques in system design, rather than on the mathematical foundations, this book is ideal for graduate students and researchers in wireless communications, as well as for wireless and telecom engineers.
In our Software Defined Radio SDR project we aim at combining two different types of standards, Bluetooth and HiperLAN/2 on one common hardware platform. Goal of our project is to generate knowledge about designing the front end of an SDR system (from the antenna signal to the channel bit stream) where especially an approach from both analog and digital perspective is essential. Bluetooth uses Gaussian Frequency Shift Keying (GFSK) as modulation technique. As QAM and GFSK signal can be demodulated by using the same type of algorithms, the outer receiver of HiperLAN/2 can be used as a Bluetooth demodulator. So, whereas most commercial Bluetooth chips are low cost and inflexible, in our project flexibility and re-use of hardware is important. It is for that reason that a part of the channel selection and demodulation will
be done in the digital domain. The choice of the demodulation algorithm determines the channel selection requirements (better demodulation algorithms require less SNR). This work analyzes the performance of several Bluetooth (GFSK) demodulation and decision algorithms using single bit decision. A simulation model was built to measure the performance of these algorithms. In our simulation
model, low-IF or zero-IF Bluetooth signals are sampled with 80 MHz to get a realistic setting. The synchronization word in the Bluetooth packet is used for bit synchronization. To obtain a BER (Bit Error Rate) of 0.1%, specified by the Bluetooth standard, the best combination of demodulation and decision algorithm requires an
SNR of about 15 dB. Ongoing research focusses on several subjects: multibit decision, advanced demodulation algorithms (such as (adaptive) decision feedback equalizers) and bit-synchronization algorithms.
Wireless Local Area Networking standard (Wi-Fi) and the WPAN standard (Bluetooth and Zigbee) products utilize the same unlicensed 2.4 GHz ISM band. Co-existence between such wireless technologies within the same frequency spectrum is crucial to ensure that each wireless technology maintains and provides its desired performance requirements. This paper provides a brief description of the newly introduced Zigbee standards including the Physical (PHY) and media access control (MAC) layer. It focuses on developing MatLab/Simulink models for the Zigbee protocol and the performance evaluation of these models. Several simulations were run and the results were analyzed for the different scenarios. The results showed how the relationship between the signal Bit Error Rate (BER) and Signal to Noise Ratio (SNR) was affected when varying the data rate and power. Furthermore, this paper investigated the co-existence of WLAN (IEEE 802.11g) with Zigbee (IEEE 802.15.4 by quantifying potential interferences and examining the impact on the throughput performance of IEEE 802.11g and Zigbee devices when co-existing within a particular environment. The effect of Zigbee on IEEE 802.11g was compared with the effect of Bluetooth under the same operating conditions.
Due to wide power spectrums of rectangular data streams, it is important for base-band signals to be heavily band limited before modulation. That can be achieved by pulse shaping of rectangular bits. Some of the most common are a half-sine pulse shaper and a Gaussian pulse shaper which are used in Minimum Shift Keying (MSK), Gaussian Minimum Shift Keying (GMSK) and Gaussian Frequency Shift Keying (GFSK) modulations, respectively. The most common solutions of such shapers use PCM based look-up-table (LUT), which requires an nbit D/A converter. We proposed the use of a 1-bit Sigma Delta Modulation (SDM) LUT, which results in smaller ROM capacity, a 1-bit wide output word, and a simple1-bit D/A converter realized as an out-of-chip first-order lowpass RC filter, or an in-chip charge pump. This article describes a simple, but efficient SDM LUT-based half-sine and Gaussian shaper that can be used for generation of MSK and GMSK/GFSK modulated signals. Oscillograms and power spectrums are measured on SDM LUT realized in FLEX AlteraTM PLD, for a 10-bit pseudo-noise sequence test input signal.
Much of Bluetooth's data remains confidential in prac- tice due to the difficulty of eavesdropping it. We present mechanisms for doing so, therefore eliminating the data confidentiality properties of the protocol. As an addi- tional security measure, devices often operate in "undis- coverable mode" in order to hide their identity and pro- vide access control. We show how the full MAC address of such master devices can be obtained, therefore bypass- ing the access control of this feature. Our work results in the first open-source Bluetooth sniffer.
Gaussian frequency shift keying (GFSK) modulation is widely used in low data-rate wireless audio/video transmission and personal communication standards like Bluetooth. In this letter, least squares (LS) and maximum likelihood (ML) methods are exploited for decision-aided carrier recovery in a GFSK receiver. Through the analysis of estimation error variance, we show that the LS/ML carrier frequency offset estimation method outperforms the conventional method using the DFT approach. Besides, the new method is also effective to deal with non-DC-free data sources. Simulation results show that the new decision-aided GFSK receiver achieves better results than the feedforward receivers with DC-free and non-DC-free sources.
Frequency Hopping Spread Spectrum (FHSS) is a technique that wireless devices communicate in a way that the transmission frequencies are alternated in a pre-determined ordered hopping pattern known only to the sending and receiving devices. Therefore, it has become one of the key security features in modern wireless networking and has been adopted in many applications, civilian and military, including wireless sensor networks and military satellites as a secure and efficient data transfer scheme. In this paper, the performance of frequency hopping selection kernel, used in the IEEE 802.15 standard (Bluetooth) to implement FH technique, will be estimated and evaluated. Theoretical analysis and simulation results verified that, compared to purely random hopping sequences, the Bluetooth hopping sequence offers noticeable residual correlations and periodic cross-correlations features. Results, also, proved that a combination of time slot synchronization and inter-piconet offset control leads to lower collision rate rather than time slot synchronization only.
For transmission of multimedia data via ad-hoc networks, the next-generation Bluetooth specification, Bluetooth EDR (Enhanced Data Rate) was developed recently. The design issues of the Bluetooth EDR are how area-efficiently three modulation schemes—GFSK, π/4-shifted DQPSK and 8-DPSK—are combined, and how fast and simply they perform seamless timing and carrier recovery as the demodulation scheme is changed to receive enhanced-rate data. So we proposed 6 hardware or software schemes for area reduction and simple implementation, and designed a Bluetooth EDR baseband controller using those schemes. We especially proposed and designed a simple scheme that compensates carrier frequency offset by using an average of phase errors between adjacent symbols. The FPGA implementation integrated with link manager software was tested with Bluetooth EDR specification, and was shown to be fully functional with enhanced data rates of 2 Mbps and 3 Mbps in spite of switching of modulation method during packet transmission. Timing recovery was completed within 10 μs which is shorter than 11 μs assigned to synchronization sequence after GFSK demodulation, and the coverage of frequency offset was 100 kHz which is wider than 40 kHz of the specification.
The generation of minimum shift keying (MSK) requires a linear variation of the phase, hence a constant frequency of the optical carrier. However, the generation of the optical phase may be preferred by driving an optical modulator using sinusoidal signal for practical implementation. Thus a nonlinear variation of the carrier phase, hence some distortion effects are produced. In this paper, we investigate the use of linear and nonlinear phase shaping filtering and their impacts on MSK modulated optical signals transmission over optically amplified long haul communications system. The evolution of the phasor of the in-phase and quadrature components is illustrated for lightwave-modulated signal transmission. The distinct features of three different MSK modulation formats: linear MSK, weakly nonlinear MSK and strongly nonlinear MSK and their transmission are simulated. Transmission performance obtained indicates the resilience of the MSK signals in transmission over multi-optically amplified multi-spans.
Transmitter Modulated Waveforms after Applying FHSS: (a) Utilizing GFSK, (b) Utilizing π/4 DQPSK, (c) Utilizing π/8 D8PSK. -Units: Horizontal Axis Time in Seconds and Vertical Axis Amplitude
- Fig
Fig. 7. Transmitter Modulated Waveforms after Applying FHSS: (a) Utilizing GFSK, (b) Utilizing π/4 DQPSK, (c) Utilizing π/8 D8PSK. -Units: Horizontal Axis Time in Seconds and Vertical Axis Amplitude. Fig.
Design of ZigBee Transceiver for IEEE 802.15.4 Using MATLAB/SIMULINK Master of Technology Disseration, National Institute of technology
- R Kanna
Digital Modulation Techniques, Second Edition (Artech House Telecommunications Library)
- F Xiong
Modulation techniques in bluetooth wireless technology
- J Gillen