FSK Modulation Research Articles

Exploring Practical Aspects of the FSK Modulation with Non-Coherent Matched Filter Detection

Exploring Practical Aspects of the FSK Modulation with Non-Coherent Matched Filter Detection

A CMOS front-end for RFID transponders using multiple coil antennas

A front-end architecture for inductive RFID transponders using multiple coil antennas for reduced orientation sensitivity is presented. The front-end uses multiple antennas for reception and one antenna for transmission. A select function identifies the antenna that is most favorably oriented toward the reader for transmission by comparing the DC charge-up phases of multiple DC generation blocks during power-up of the transponder. Design, simulations and measurement results of a front-end manufactured in 0.35 $$\upmu$$μm CMOS for 125 kHz FSK modulation are presented for a pulsed RFID system as well as an architecture for cascaded DC generation. This paper also includes a design example of a coil antenna for spherical transponders using three independent orthogonal windings.

Superregenerative Reception of Narrowband FSK Modulations

In this paper we investigate the possibilities of narrowband FSK detection using a superregenerative (SR) receiver. Previous SR FM demodulation techniques rely on detecting the amplitude variations caused by the different frequencies involved in FSK modulation. However, this requires relatively high frequency deviations because the frequency response of SR receivers is not very selective. In this paper we take a different approach, exploiting the distinct phase trajectories of FSK modulations resulting from the transmitted data. The well-known fact that the SR oscillator response preserves the phase information of the received signal is successfully exploited to allow the detection of several FSK modulations. These include the special case of MSK, opening the way to applying the SR principle to several communication standards, such as IEEE 802.15.4. The key ideas for symbol synchronization are also presented. Experimental results on a 10 kbit/s proof-of-concept MSK receiver, achieving a sensitivity better than -114 dBm in the HF band, validate the proposed approach.

IJARCCE - Computer and Communication Engineering

The modern communication systems and software radio based applications demands smart transceivers, consisting of only an antenna and a fully programmable circuit with digital modulators and demodulators. A basic communication system's transmitter modulates the amplitude, phase or frequency proportional to the signal being transmitted. An efficient solution (that doesn't require large tables/memory) for realizing universal modulator is CORDIC (CO-ordinate Rotation Digital Computer) algorithm. The CORDIC algorithm is used in the rotation mode, to convert the coordinates from polar mode to rectangular mode. CORDIC is a versatile algorithm widely used for VLSI implementation of digital signal processing applications. This paper presents how to use CORDIC to implement different communication subsystems that can be found in software defined radio. Specifically, it shows how to use CORDIC to implement direct digital synthesizers and ASK, PSK, FSK Modulators. The focus of this paper is to analysis and simulation of ASK, FSK, PSK modulation scheme using Direct Digital Synthesizer having CORDIC algorithm at the place of ROM Look up Table. CORDIC Algorithm provides many significant advantages over Conventional ROM Look up Table.

Energy Metering by using Power Line Communication

Everywhere automation is needed to reduce the work. We decided to put in to practice the meter reading using power line communication. It can be measure real time and also save the time. It had better user interface and digital data analysis. Data was send over existing carrier by using power line that's minimizes the complexity and cost of system. Energy meter reading was a monotonous and costly work. The meter reader people run through each meter and catch the meter reading manually to issue the bill which will later be entered in the billing software for payment automation. If the manual meter reading and bill data entry process can be automated then it minimizes the hard task and financial wastage system. It was used for data collecting from the meter and processing the collected data for billing and other decision purposes. We had proposed an automatic meter reading system which was low cost, high performance and cover highest coverage area. In the data receiving and processing unit meter reading was collected from the transceiver which controlled by another microcontroller. There was computer application that will take the data from the microcontroller. This was help to avoid any tampering or break down of energy. KeywordsARM7 controller, FSK Modulator IC 555, FSK Demodulator IC 565, Power line isolation __________________________________________________*****_________________________________________________

FPGA Implementation of ASK and FSK Modulator Based on Matlab/Xilinx System Generator

FPGA Implementation of ASK and FSK Modulator Based on Matlab/Xilinx System Generator

A sub-nW 2.4 GHz Transmitter for Low Data-Rate Sensing Applications.

This paper presents the design of a narrowband transmitter and antenna system that achieves an average power consumption of 78 pW when operating at a duty-cycled data rate of 1 bps. Fabricated in a 0.18 µm CMOS process, the transmitter employs a direct-RF power oscillator topology where a loop antenna acts as a both a radiative and resonant element. The low-complexity single-stage architecture, in combination with aggressive power gating techniques and sizing optimizations, limited the standby power of the transmitter to only 39.7 pW at 0.8 V. Supporting both OOK and FSK modulations at 2.4 GHz, the transmitter consumed as low as 38 pJ/bit at an active-mode data rate of 5 Mbps. The loop antenna and integrated diodes were also used as part of a wireless power transfer receiver in order to kick-start the system power supply during energy harvesting operation.

Technical Analysis of the PLC Access Networks

This paper introduces the PLC in the application of network technology, the characteristics of information channels of power line are analyzed, this paper discusses two kinds of modulation method, and contrast the FSK and OFDM modulation technology to make clear their respective features, finally summarizes the PLC access network technology based on OFDM modulation technology, the remarkable advantages of OFDM modulation technology are defined.

M-ary FSK Modulation Using Short Packet without a Preamble and Error Detection Codes for Low Power Wireless Communication

Since power of a wireless sensor node is limited, low power communication technology has been required. M-ary frequency shift keying (MFSK) modulation with orthogonal signals is one of the methods to decrease the power. However, if the amount of transmitted data including such as an identification number (ID) of a node and measured data is small, a ratio of the data length to the total packet length, which means transmission efficiency, becomes quite low. Because a preamble and error check codes are generally added to a packet for synchronization between a transmitter and a receiver and for decrease in reception errors, respectively. In this research, we have developed a method with digital filters which eliminates the other signals from time series frequency spectra not to use a preamble and error check codes. Although estimated synchronization loss of the method was less than 1.6 dB, it was found that the loss of the method on error packet rate was almost 0 dB at more than 0.001 of packet error rate by a simulation made by BASIC. These results indicate a possibility to realize that a packet which consists of only two symbols can be received with no error if the transmitted data is less than 14 bits using 128-FSK.

DigPLL-Lite: A Low-Complexity, Low-Jitter Fractional-N Digital PLL Architecture

This paper introduces a novel architecture of digital PLL. The goal of this architecture is to reach low jitter, fractional operation, and FSK modulation capability with low architecture complexity for small area, low power, and minimal design effort. The architecture is based on the bang-bang phase detector, so that usage of time-to-digital-converter circuits is avoided, with no need for any background calibration. The key enabling blocks are a phase interpolator-based exact fractional frequency divider, and a multi-output bang-bang phase detector. The prototype implemented in 130 nm reaches 1-psrms absolute jitter while operating in integer mode and 1.9 psrms absolute jitter while operating in full fractional mode, with an output frequency of 1 GHz and reference frequency of 25 MHz, consuming 7.4 mW from a supply of 1.3 V. FSK modulation of the 1 GHz carrier up to 300 kbps with a frequency deviation of ±150 kHz is also implemented and measured .

Robust Ultra-Low Latency Soft-Decision Decoding of Linear PCM Audio

Applications such as professional wireless digital microphones require a transmission of practically uncoded high-quality audio with ultra-low latency on the one hand and robustness to error-prone channels on the other hand. The delay restrictions, however, prohibit the utilization of efficient block or convolutional channel codes for error protection. The contribution of this work is fourfold: We revise and summarize concisely a Bayesian framework for soft-decision audio decoding and present three novel approaches to (almost) latency-free robust decoding of uncompressed audio. Bit reliability information from the transmission channel is exploited, as well as short-term and long-term residual redundancy within the audio signal, and optionally some explicit redundancy in terms of a sample-individual block code. In all cases we utilize variants of higher-order linear prediction to compute prediction probabilities in three novel ways: Firstly by employing a serial cascade of multiple predictors, secondly by exploiting explicit redundancy in form of parity bits, and thirdly by utilizing an interpolative forward/backward prediction algorithm. The first two presented approaches work fully delayless, while the third one introduces an ultra-low algorithmic delay of just a few samples. The effectiveness of the proposed algorithms is proven in simulations with BPSK and typical digital microphone FSK modulation schemes on AWGN and bursty fading channels.

A reconfigurable upper audio band modem for data communication between mobile devices

For communicating short data sequences over small distances, the use of devices with conventional wireless radio frequency interfaces requires standardized hardware, dedicated infrastructure and appropriate Link/Network layer protocols. To address challenges associated with these requirements, a communication mechanism using devices which support simple audio interfaces (speakers and microphones) is proposed using the upper audio band (UAB) of frequencies (16---20 kHz). Devices with audio interfaces can be deployed in a personal area network for communicating at low data rates over small distances. Multi-tone FSK modulation is used for transmitting Reed---Solomon encoded data over the UAB. For peer-to-peer communication applications, a sensing mechanism is enabled on the receiving device to sense for empty time---frequency slots and schedule its data transmission at the appropriate times. A system prototype is developed using portable speakers and smartphones with sensitive microphones. The effective throughput of the modem is evaluated for different sensing durations and distances. Ad-hoc peer-to-peer networks can be enabled between mobile devices for communicating short data sequences based on the UAB modem.

Analysis, Design and Implementation of FSK Modulate Systems

The hybrid signals are the combined signals with multi-modulation mode. With multi-modulation, the disadvantages of single-modulation (such as FSK, PSK and PPM) can be eliminated. By taking the advantages of different modulations, the performance of range resolving, Doppler resolving and low probability of intercept (LPI) of the signal can be improved. FSK/PSK radar signal is the signal with both FSK and PSK modulation at one time. It is with large Bandwidth Time product (BT), thumbtack-like ambiguity function and well ability of Anti-EMI. The FSK/PSK signals of which the frequency-hopping and bi-phase sequences were randomly chosen often had high side lobe level. With the simulation and analysis using MATLAB, the method of FSK modulation is made analysis. As a result, the automatic modulation recognition is one of the necessary functions.

협대역 통신 환경에서 Dual-band FSK 변조 방식을 이용한 주파수 옵셋 감쇄 기법

In narrowband communication systems operating in VHF and UHF bands, the performance degradation due to a frequency offset is inevitable. In this paper, we propose a frequency offset reduction scheme using the dual-band FSK modulation for narrowband communications. The proposed scheme not only offer a relatively reliable performance under a severe frequency offsets, but also can obtain a frequency diversity gain in Rayleigh fading channel.

Research on Channel Codec of DCR System Based on CMX7141

This article introduces a digital private network of mobile communication dedicated chipset CMX7141 that used for the 4FSK modulation and demodulation in DCR system, and introduces the application of CMX7141 inthe DCR system. Focus research on the channel codec techniques of the chip and have a simulation on the channel coding and decoding. The simulation results indicate that, through channel error correction technique in CMX7141, the BER of DCR system reduces greatly and the transmission quality of DCR system is improved.

A WIDEBAND FREQUENCY-SHIFT KEYING MODULATION TECHNIQUE USING TRANSIENT STATE OF A SMALL ANTENNA

The rate of wireless data transmission is limited by the antenna bandwidth. We present an e-cient technique to realize a high-rate direct binary FSK modulation by using the transient properties of high-Q antennas. We show that if the natural resonance of a narrowband resonant-type antenna is switched at a high rate, the radiating signal follows the variation of resonant frequency and provides a high-rate data-transmission regardless of the narrowband characteristics of the antenna. The bit-rate in this method is dictated by the switching speed rather than the impedance bandwidth. Since the proposed technique employs the antenna in a time-varying arrangement, carrier frequencies are not required to be simultaneously within the antenna bandwidth. When demanded, the antenna is tuned to required carrier frequency according to a sequence of digital data. Moreover, if the switching frequency is properly chosen such that the stored energy in the near-zone is not dramatically disturbed, any variation in the antenna resonance will instantaneously appear in the far-fleld radiation due to the previously accumulated energy in the near fleld. Therefore, depending on the Q factor and switching speed, radiation bandwidth of the antenna can be improved independently from the impedance bandwidth. Furthermore, we show that a single RF source is su-cient to excite both carrier frequencies and the need for a VCO is obviated. Experimental results are presented to validate the feasibility of the proposed technique.

A 1 V 5 mA Multimode IEEE 802.15.6/Bluetooth Low-Energy WBAN Transceiver for Biotelemetry Applications

This paper presents a 1 V multi-mode RF transceiver for wireless body area network (WBAN) applications. Operating in the 2.36 GHz Medical Body Area Networks (MBANs) and the 2.4 GHz Industrial, Scientific & Medical (ISM) frequency bands, the transceiver implements rotated differential-phase shift keying (DPSK) and Gaussian filtered frequency shift keying (GFSK) modulation for both IEEE 802.15.6 Narrow Band (NB) and Bluetooth Low-Energy (LE) PHY standards. Also included is a proprietary 900 MHz ISM band transmitter utilizing FSK modulation. The wireless transceiver operates half-duplex, and for IEEE 802.15.6 achieves -104/-96.5 dBm receiver input sensitivity (for 10% packet error rate) at data rates of 121.4/971.4 kbps and -94 dBm for Bluetooth LE (for 0.1% bit error rate) at 1 Mbps. Transmit power up to +3/+5 dBm is achievable for IEEE 802.15.6 and Bluetooth LE respectively. The transceiver consumes 4.8 mA during IEEE 802.15.6 & Bluetooth LE receive, and 4.6 mA during Bluetooth LE transmit at -10 dBm output power, from a 1.0 V supply. For IEE802.15.6 transmission at -10 dBm output power, 5.9 mW is consumed, dropping to 1.7 mW for proprietary 900 MHz transmission. This performance surpasses state-of-the-art power consumption and represents the first published transceiver for the IEEE 802.15.6 NB PHY standard. It is fabricated in a 0.13 μm CMOS technology and occupies approximately 5.9 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> .

An Automatic Modulation Classifier using a Frequency Discriminator for Intelligent Software Defined Radio

In this paper, we proposed a simple frequency discriminator based method to automatically identify PSK and M-ary FSK modulation schemes. This method is simpler than other methods based on statistical moments, neural networks and wavelet transforms. Also, this method can demodulate M-ary FSK signals using the classifier's output, resulting in a simple receiver structure. Results from a digital implementation are presented to show the validity of the proposed method.

Study on Acoustic Communication Methods in Periodic Tube Structure

With many periodical discontinuous boundaries, periodic tube structure is prone to inter-symbol interference in acoustic communication. To look for the appropriate communication method and improve the quality of acoustic communication in the structure, experiments were carried out in the real periodic structure using raised cosine ASK, FSK and BPSK modulation respectively. The results show that：in periodic tube structure, ASK, FSK, and BPSK all can realize normal acoustic communication in the condition without noise or the noise is weak. Raised cosine ASK modulation can better use transmission power and get the highest data rate (up to 65.7Kbps in the experimental structure) in un-noise environment. BPSK has the best noise immunity in the condition with noise. So, the BPSK is more suitable for the actual acoustic communication in periodic tube structure in the actual environment.

Analyzing and Developing Transmitter of UV Communication Test Bed

The reasons of using low-pressure mercury lamp as transmitter light source are analyzed. The principle of how the resonant half-bridge switching circuit works is described, and how to use this circuit to achieve 2FSK modulation is discussed. The L6384 chip modulation circuit is briefly introduced. The response performance of low-pressure mercury lamp is tested under the conditions of gradually increasing the transmission rates. The new transmitter has a longer transfer distance but a slower response compared with LED transmitter system.