Frequency Modulation Broadcasting Research Articles

Time Information Transmission Based on FM Broadcast Signal

The wireless communication technology is now widely used in many different applications. For example: communication, surveying and mapping, navigation and national defense and other fields. However, the frequency resources of wireless communication are becoming more and more tense, especially the related time service means used for time transmission, satellite time service, short wave time service and other technologies have been very mature. As a new time service method, time transmission using FM broadcasting additional channel will not occupy new frequency resources, nor will it interfere with the original audio broadcasting A very useful technique. In this paper, we propose a new method for transmitting time information through an additional frequency modulation (FM) broadcasting channel, based on the existing FM broadcasting technology. As a result, the transmission and reception technology required is mature and readily available, which makes this approach accessible as well as affordable. A field test was conducted, which demonstrated that the proposed method is feasible and accurate. This method meets the channel conditions and is conducive to accurate acquisition and tracking of the receiving end. This approach is expected to achieve higher accuracy, of sub-millisecond order, than existing methods, which will make it suitable for applications such as regional and battlefield formation time synchronization signal systems.

Indoor positioning using public FM and DTMB signals based on compressive sensing

Location-Based Services have become an indispensable part of our daily life, the sparsity of location finding makes it possible to estimate specific position by Compressive Sensing (CS). Using public Frequency Modulation (FM) broadcasting and Digital Television Terrestrial Multimedia Broadcasting (DTMB) signals, this paper presents an indoor positioning scheme, which is consisted of an offline stage and an online stage. In the offline stage, the Received Signal Strength (RSS) at the Reference Points (RPs) is measured, including the average and variance of public FM broadcasting and DTMB signals. In the online stage, the K-Weighted Nearest Neighbor algorithm is used to fulfill coarse positioning, which is able to narrow the selection scope of locations and choose partial RPs for accurate positioning. Then, the accurate positioning is implemented through CS. Experiment shows that the average positioning error of the proposed scheme is 1.63m. What's more, a CS-based method has been proposed in this paper to reduce the labor cost when collecting data. Experiment shows the average positioning error is 2.04m, with the advantage of a 34% labor cost reduction. Experiment results indicate that the proposed system is a practical indoor positioning scheme.

Indoor positioning using public FM and DTMB signals based on compressive sensing

Location-Based Services have become an indispensable part of our daily life, the sparsity of location finding makes it possible to estimate specific position by Compressive Sensing (CS). Using public Frequency Modulation (FM) broadcasting and Digital Television Terrestrial Multimedia Broadcasting (DTMB) signals, this paper presents an indoor positioning scheme, which is consisted of an offline stage and an online stage. In the offline stage, the Received Signal Strength (RSS) at the Reference Points (RPs) is measured, including the average and variance of public FM broadcasting and DTMB signals. In the online stage, the K-Weighted Nearest Neighbor algorithm is used to fulfill coarse positioning, which is able to narrow the selection scope of locations and choose partial RPs for accurate positioning. Then, the accurate positioning is implemented through CS. Experiment shows that the average positioning error of the proposed scheme is 1.63m. What's more, a CS-based method has been proposed in this paper to reduce the labor cost when collecting data. Experiment shows the average positioning error is 2.04m, with the advantage of a 34% labor cost reduction. Experiment results indicate that the proposed system is a practical indoor positioning scheme.

An Improved Mathematical Scheme for LTE-Advanced Coexistence with FM Broadcasting Service.

Power spectral density (PSD) overlapping analysis is considered the surest approach to evaluate feasibility of compatibility between wireless communication systems. In this paper, a new closed-form for the Interference Signal Power Attenuation (ISPA) is mathematically derived to evaluate interference caused from Orthogonal Frequency Division Multiplexing (OFDM)-based Long Term Evolution (LTE)-Advanced into Frequency Modulation (FM) broadcasting service. In this scheme, ISPA loss due to PSD overlapping of both OFDM-based LTE-Advanced and FM broadcasting service is computed. The proposed model can estimate power attenuation loss more precisely than the Advanced Minimum Coupling Loss (A-MCL) and approximate-ISPA methods. Numerical results demonstrate that the interference power is less than that obtained using the A-MCL and approximate ISPA methods by 2.8 and 1.5 dB at the co-channel and by 5.2 and 2.2 dB at the adjacent channel with null guard band, respectively. The outperformance of this scheme over the other methods leads to more diminishing in the required physical distance between the two systems which ultimately supports efficient use of the radio frequency spectrum.

A melanoma trend forecast from 2002 – What happened then?

ABSTRACTIn 2002, a paper was published that highlighted the strong correlation noticed between melanoma incidence and the number of surrounding frequency modulation (FM) transmitters in the Nordic countries since 1955. In the report the development of future numbers of melanoma cases in Estonia were estimated since they got the FM broadcasting system rolled out not until 1992. Here, we report what happened since then in Estonia regarding melanoma cases per year. We also comment on the recent development in the Nordic countries, which is not very reassuring from a public health point of view. The last 10 years of melanoma incidence trends, increasing at an exponential rate, suggest that responsible authorities now need to consider possible influences also from other radiation sources in addition to UV radiation from the sun.

The Right Stuff? The Original Double Jay as Site for Youth Counterculture

The Right Stuff? The Original Double Jay as Site for Youth Counterculture

Propagation Effects on Linear Modulation Schemes in Tropospheric Communication

In this paper, the performance evaluation of Differential Quadrature Phase Shift Keying (DQPSK) and Quadrature Amplitude Modulation-16(QAM) in the propagation of signal through troposphere is presented. Very High Frequency (VHF) range is widely used in FM(frequency modulation) broadcasting, satellite television, air traffic controlling (ATC), navigational aids in addition to the modern third generation high speed data communications. However the factors like rain, wind and dust causes impairments to the communication process to a great extent. So the proper modeling of the propagation channel in tropospheric communication, considering these factors is necessary. By choosing a suitable modulation scheme and using effective channel coding the signals can be faithfully communicated. In this work, the bit error rates (BER), scatter plot and eye diagrams are simulated to compare the performance of communication.

Coexistence of OFDM-Based IMT-Advanced and FM Broadcasting Systems

Coexistence analysis is extremely important in examining the possibility for spectrum sharing between orthogonal frequency-division multiplexing (OFDM)-based international mobile telecommunications (IMT)-Advanced and other wireless services. In this letter, a new closed form method is derived based on power spectral density analysis in order to analyze the coexistence of OFDM-based IMT-Advanced systems and broadcasting frequency modulation (FM) systems. The proposed method evaluates more exact interference power of IMT-Advanced systems in FM broadcasting systems than the advanced minimum coupling loss (A-MCL) method. Numerical results show that the interference power is 1.3 dB and 3 dB less than that obtained using the A-MCL method at cochannel and adjacent channel, respectively. This reduces the minimum separation distance between the two systems, which eventually saves spectrum resources.

FM Broadcasting Exposure Time and Malignant Melanoma Incidence

Object: To analyze the age-specific incidence of malignant melanoma in Sweden since 1958 in order to see if the reported general increase in incidence would be explained by a sudden exposure to an environmental stress to the population. Methods: Incidence data for all age groups was collected from the Swedish National Board of Health and Welfare databases for each year between 1958 and 2002. The incidence in all 288 municipalities of Sweden was correlated to the number of FM transmitters covering each municipality. Results: The age-specific incidence was found to be constant over the last 20–30 years for people younger than 50 years while the incidence for older age groups still are constantly increasing. The total incidence in different municipalities was found to be a strong function of the number of covering FM transmitters. Conclusions: The age-specific incidence of malignant melanoma of the skin appears to be following a pattern of response to an imposed environmental change in 1955. We believe that the frequency modulation (FM) broadcasting radiation at whole-body resonant frequencies is such an environmental stress.

The determination and importance of internal capacitances of transistors in the frequency band of commercial FM broadcasting

Using a single-capacitor Colpitts oscillator a method has been proposed for determination of internal capacitances of bipolar junction transistors (BJTs) and junction field effect transistors (JFETs) in the frequency band of commercial frequency modulation (FM) broadcasting. Variation of these capacitances with the operating bias point and the operating frequency of the active device has been considered. Practical implementation of this method does not require any unconventional measuring system. The changing behavior of the base-emitter capacitance of BJTs versus operating bias current has been utilized for designing a simple high-frequency amplitude-modulating (AM) system. This efficiently designed AM signal generator does not have any transformer and is an example showing the importance of internal capacitances of active devices.

A non-uniform sampling tangent type FM demodulation

Frequency modulation (FM) is widely used in applications such as FM broadcasting, Global System for Mobile (GSM, whose modulation method, Gaussian minimum shift keying, is a kind of FM) etc. Using digital signal processing (DSP) to demodulate FM signals has advantages over analogue methods in respect of the easiness of design, adjustment, stability, reliability, and upgrading. The current digital methods employ an even spaced (uniform) sampling method and process each sample. When the modulation index increases, the modulated signal bandwidth expands. So the sampling rate needs to be increased as well. This leads to increased computation time especially for division and arctangent. In this paper, we propose a non-uniform low-sampling method, whose overall sampling rate is not a function of the modulation index. Its minimum rate can be as small as four times the bandwidth (B) of the non-modulated (message) signal. Furthermore, the minimum rate of division and arctangent computations are only 2B Hz. As a result, the proposed method can significantly reduce the overall computation for FM demodulation.

Melanoma incidence and frequency modulation (FM) broadcasting.

The incidence of melanoma has been increasing steadily in many countries since 1960, but the underlying mechanism causing this increase remains elusive. The incidence of melanoma has been linked to the distance to frequency modulation (FM) broadcasting towers. In the current study, the authors sought to determine if there was also a related link on a larger scale for entire countries. Exposure-time-specific incidence was extracted from exposure and incidence data from 4 different countries, and this was compared with reported age-specific incidence of melanoma. Geographic differences in melanoma incidence were compared with the magnitude of this environmental stress. The exposure-time-specific incidence from all 4 countries became almost identical, and they were approximately equal to the reported age-specific incidence of melanoma. A correlation between melanoma incidence and the number of locally receivable FM transmitters was found. The authors concluded that melanoma is associated with exposure to FM broadcasting.

An Aural Monitor for Frequency Modulation

In television sound and other frequency modulation broadcasting, a practical operating problem exists wherein the usual station monitoring is ineffectual. The requirements of a truly representative aural monitor can be met by proper application and adjustment of a slope detector. Two units embodying this principle are described.

Ultra-High Frequency Radio For Students

THESE Second World War and the succeeding years have seen a great extension of the use of radio waves of very high frequency, largely as a result of the stimulus provided by the development of radar, and of television and frequency-modulation broadcasting systems. It is therefore perhaps not surprising that there have appeared recently several books on matters associated with the use of such short waves. However, it might be suggested that the time has now been reached when intending authors and publishers in this field should consider carefully what they have to offer before adding to the list. One might particularly emphasize that it seems scarcely necessary nowadays to include a treatment of vector analysis, and a detailed derivation of Maxwell's equations, together with the fundamental principles underlying electromagnetic radiation, in every new text dealing with very high frequency radio phenomena. Ultra-high Frequency Transmission and Radiation By Nathan Marchand. Pp. ix + 322. (New York: John Wiley and Sons, Inc.; London: Chapman and Hall, Ltd, 1947.) 27s. net.