Design and Implementation of Bpsk Modulator and Demodulator Using Vhdl

Singh

2022

IJECE

Underutilized radio frequencies are the chief apprehension in advance radio communication. The radio recourses are sparse and costly and their efficient allocation has become a challenge. Cognitive radio networks are the ray of hope. Cognitive radio networks use dynamic spectrum access technique to opportunistically retrieve and share the licensed spectrum. The licensed users are called primary users and the users that opportunistically access the licensed spectrum all called secondary users. The proposed system is a feedback system that work on demand and supply concept, in which secondary receivers senses the vacant spectrum and shares the information with the secondary transmitters. The secondary transmitters adjust their transmission parameters of transmit power and data rate in such a way that date rate is maximized. Two methods of spectrum access using frequency division multiple access (FDMA) and Time division multiple access (TDMA) are discussed. Interference temperature limit and maximum achievable capacity are the constraints that regulate the entire technique. The aim of the technique is to control the transmitter power according to the data requirements of each secondary user and optimizing the resources like bandwidth, transmit power using machine learning and feed forward back propagation deep neural networks making full use of the network capacity without hampering the operation of primary network.

Section: Proposed Methods 21 System and Frequency Modelmentioning

confidence: 99%

Transmit power control and data rate enhancement in cognitive radio network using computational intelligence

Singh

2022

IJECE

“…Both, the modulating signal and the carrier are generated internally the modulating signal by a LFSR and the carrier by a DDS Compiler. The modulated signal is obtained at the output of a mux block and then, passed through a communication channel where noise is added [5].…”

Section: Iirelated Workmentioning

confidence: 99%

“…BPSK refers to the technique of modifying the carrier phase of a signal both before transmission and after receipt. Although there are numerous techniques that could have been utilized to transmit and receive the data, BPSK was chosen for its simplicity and robustness [2], [5].…”

Section: Ivproposed Systemmentioning

confidence: 99%

Design of Digital Baseband Subsystem for S-Band Transponder

V.Jayasudha¹,

Lakshmi²

2015

IJAREEIE

ABSTRACT:A Digital Transponder collects signals in the range of uplink frequencies and transmits them on a different set of downlink frequencies to receivers on Earth. The Transponder consists of RF Receiver; RF Transmitter & digital Baseband Subsystem. In the Digital Baseband Subsystem, the Receiver performs the demodulation of the uplinked command signal down to the data level. The Transmitter linearly phase modulates the Telemetry video signal on a Baseband Transmitter and generates the required RF power before transmission. In this paper, BPSK modulator and demodulator are designed by using VHSIC Hardware Description Language (VHDL) and implemented in Spartan 3E FPGA kit. The Digital Baseband subsystem is used in Spacecraft applications.

“…Depending on purpose and requirement of user such as: weight, size, volume, budget, orbit, altitude, lifetime or payload of satellite, each transmitter was designed to satisfy these requirements [1]- [25]. These transmitters focused on solving problems: survey and compare result of method approaches [5], [6], effect of environment to this module [2], increase bandwidth [5], [11], [14], [21], increase power output [7], [16], decrease cost [3], approach very high speed integrated circuit (VHSIC) hardware description language (VHDL) in modulator [15]. Recently, variety of transmitter approached multi-stages power amplifier [11]- [13], [22], [23], or using Wilkinson power combiner method [7], [10], using technology in transmitter architecture [17] to increase power output.…”

mentioning

confidence: 99%

Design and implementation of an S-band transmitter for nanosatellites with new configuration

Doan

Duong

2022

IJEECS

In this paper, the author presents the design and implementation of an Sband transmitter for nanosatellites. By combining heterostructure field effect transistors (HFET) and laterally diffused metal–oxide–semiconductor (LDMOS) technology and using flexible structure and flexible control method, this research obtained 60 dB gain power when input is -14 dBm, output power is 46 dBm (more than 25 W) in 2,1 GHz -2,3 Ghz frequency; phase noise is -80 dBc/Hz at 100 KHz offset frequency. Unlike other traditional transmitters, this transmitter was designed with multi-stages which have multi-peaks resonance to expand bandwidth to respond to the requirement of generation of the complex signal in wide band. Moreover, the phase locked loop (PLL) in frequency synthesizer makes the frequency conversion more flexible and output frequency more stable; thermal problem in module also was solved by using thermistor and operation mode. Measurement results prove that the design does not only satisfy the requirements of nanosatellites but also can be applied to other satellites together with their ground station because it has open configure with flexible structure and flexible control method.