PLL is a good way to do FM demodulation in analogue domain ,A PLL system can be used to implement an FM demodulator. When a PLL is locked on an FM signal, the VCO tracks the instantaneous frequency of that signal. Since the VCO output tracks the FM signal, and the VCO input voltage is proportional to the VCO output frequency, then the VCO input will be equal to the demodulated signal.

see more http://freecircuitdiagram2009/09/17/pll-fm-demodulator/ (circuit diagram and more)

A disadvantage of the PLL technique is that it trickier to get ....etc

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LOYOLA INSTITUTE OF TECHNOLOGY & MANAGEMENT
Department of Electronics and Communication Engineering
Technical Seminar on

GMSK DEMODULATOR USING COSTAS LOOP FOR SOFTWARE-DEFINED RADIO

ABSTRACT

DSP based implementation of Gaussian Minimum Shift Keying (GMSK) demodulator using Costas loop has been described. The demodulator consists of a Costas loop for carrier recovery, data recovery, and phase detection. For low data rates, ....etc

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ABSTRACT
Voice (and fax) service over cable networks is known as cable-based Internet Protocol (IP) telephony. Cable based IP telephony holds the promise of simplified and consolidated communication services provided by a single carrier at a lower cost than consumers currently to pay to separate Internet, television and telephony service providers. Cable operators have already worked through the technical challenges of providing Internet service and optimizing the existing bandwidth in their cable plants to deliver high ....etc

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LOYOLA INSTITUTE OF TECHNOLOGY & MANAGEMENT
Department of Electronics and Communication Engineering
Technical Seminar on

GMSK DEMODULATOR USING COSTAS LOOP FOR SOFTWARE-DEFINED RADIO

ABSTRACT

DSP based implementation of Gaussian Minimum Shift Keying (GMSK) demodulator using Costas loop has been described. The demodulator consists of a Costas loop for carrier recovery, data recovery, and phase detection. For low data rates, ....etc

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1.0 Digital Modulation
Firstly, what do we mean by digital modulation? Typically the objective of a digital communication system is to transport digital data between two or more nodes.In radio
Communications this is usually achieved by adjusting a physical characteristic of a sinusoidal carrier, either the frequency, phase, amplitude or a combination thereof. This is performed in real systems with a modulator at the transmitting end to impose the physical change to the carrier and a demodulator at the receiv ....etc

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Micro Controllers
(Cable Modems)


ABSTRACT

The present need to access internet in homes, offices, companies
etc in affordable way results in selection of efficient technology and
as a result cable modems are used. Cable modem technology brings high-
speed broadband networking to desired places through cable television
lines. Cable modems are devices that allow high-speed access to
information at a distant server may it be Internet server or video on
demand server, via a cable television ....etc

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how can i design am demodulator and modoulator using microcontroller?
please help me.
Tnx. ....etc

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Matlab code for superhetrodyne am receiver ....etc

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Turbo Codes

Increasing demand for information exchange is a characteristic of modern civilisation. The transfer of information from the source to its destination has to be done in such a way that the quality of the received information should be as close as possible to the quality of the transmitted information.The information to be transmitted can be machine generated (e.g., images, computer data) or human generated (e.g., speech). Regardless of its source, the information must be translated into ....etc

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ABSTRACT
The SATMODE system provides a revolutionary low cost solution for low data rate transmission over satellite, in support of interactive television services. This low cost is achieved through the introduction of constant envelope modulation, and efficient channel coding techniques. The SATMODE system specifications will be proposed as a new Cenelec standard in Europe. The lac k of an efficient and scalable return path has always limited true interactivity over satellite TV. Remote interactivity is the key element ....etc

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CDMA Mobile Communication & IS-95
 Most of the slides are stolen from Prof. Abhay Karandikar’s lecture
 Spread Spectrum Priniciples
 Does not attempt to allocate disjoint frequency or time slot resources
– Instead, this approach allocates all resources to simultaneous users, controlling the power transmitted by each user to the minimum required to maintain a given SNR
 Each user employs a noise-like wideband signal occupying the entire frequency allocation
 Each user contributes to the back ....etc

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Introduction
Increasing demand for information exchange is a characteristic of modern civilisation. The transfer of information from the source to its destination has to be done in such a way that the quality of the received information should be as close as possible to the quality of the transmitted information.

The information to be transmitted can be machine generated (e.g., images, computer data) or human generated (e.g., speech). Regardless of its source, the information must be translated into a set of signals optimized for the channe ....etc

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(Code Division Multiple Access) A method for transmitting real-time signals over a shared portion of the spectrum. The foremost application of CDMA is the digital cellular phone technology that operates in the 800MHz band and 1.9GHz . Unlike GSM and TDMA, which divides the spectrum into different time slots CDMA uses a spread spectrum technique to assign a code to each conversation. After the speech codec converts voice to digital, CDMA spreads the voice stream over the full 1.25MHz bandwidth of the CDMA channel coding each stream separately s ....etc

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