Query: Digital modulation thecniques comparison

title: Performance Comparison of Various Digital Modulation Schemes based on Bit Error Rate under AWGN Channel
abstract: In 21st century most of the technology works is on digital mode whether it's AI or digital communication. Digital signals require modulation for transmitting data from one place to another. There are many techniques available for modulating digital signals but the most commonly used are Binary Amplitude Shift Keying (BASK) Binary Phase Shift Keying (BPSK) and Binary Frequency Shift Keying (BFSK) These techniques are selected on the basis of factors like low Signal to Noise Ratio (SNR) low Bit Error Rate (BER) complexity of design and final cost of the product etc. This paper will focus on the performance comparison of theoretical and simulated BER of above three schemes and then comparing the BER of all three schemes in same conditions and predicting the best technique for digital signal transmission. The simulation is done in the MATLAB software.

title: An analysis of BER comparison of various digital modulation schemes used for adaptive modulation
abstract: In this paper, a comparative analysis of BER performance of various higher order digital modulation techniques for channel utilization is proposed and the analysis are carried out with SNR as the reference parameter. This performance analysis yields to adaptive modulation technique which can be used to attain high spectral efficiency by modulating the signal at higher order modulation schemes based on channel state information (CSI) from the receiver. Signal over AWGN channel is assumed for the analysis. To achieve lower BER values for a specific SNR, techniques to alter signal characteristics like pulse shaping filters, matching filters and convolution encoding are applied and analysis are carried out. An observation from the above analysis produces lower BER. For 256 QAM at SNR of 20, BER of 4.76x10 3 and grey coded BER of 3.83x10 4 is obtained. Highest possible modulation technique is selected with lower BER obtained. Thus, spectral efficiency which is the prime objective of the proposed paper is achieved. The above results are computed and simulated using MATLAB.

title: Comparison of BER for Various Digital Modulation Schemes in OFDM System
abstract: In this paper, an OFDM system model is developed for various digital modulation techniques BPSK, QPSK, 8QAM, 16QAM, 32QAM, 64QAM, 128QAM, 256 QAM and 512QAM using simulation in Matrix laboratory language (MATLAB) on which BER calculations is carried out. The OFDM signal was transmitted over the AWGN channel for various signal to noise ratio (SNR) values. To evaluate the performance, for each SNR level, the received signal was demodulated and the received data was compared to the original information. The result of the simulation is shown in the plot of the bit error rate versus Eb /No, which provides information about the system's performance. The convolution coding and interleaving is applied to improve BER performance of OFDM system.

title: Comparison of BER Analysis in OFDM Using Linear and Cyclic Block Codes for Different Digital Modulation Techniques
abstract: Orthogonal frequency division multiplexing (OFDM) is a type of digital modulation technique which is used in wireless communication systems. It is an efficient multicarrier modulation technique, in which large bandwidth is divided into parallel narrow bands each of which is modulated by different subcarriers. All the subcarriers are orthogonal to each other and hence it reduces the interference among various subcarriers. But OFDM suffers from high peak to average power ratio(PAPR) high complexity in design. The performance parameter of OFDM can be measured in terms of Bit error rate (BER) Lower the BER value, higher is the efficiency of OFDM system. Various methods are used to enhance the BER performance. Channel coding is the one way of enhancing the BER. This paper discusses the performance of OFDM using linear cyclic block coding for different digital modulation techniques. Bit error rate (BER) is used to measure the performance of OFDM systems.

title: Comparison of Different Digital Modulation Techniques in LTE System using OFDM AWGN Channel: A Review
abstract: In this paper there is comparison of all the modulation techniques which are possible to be used in LTE systems in OFDM AWGN channel.  .The paper gives modulation technique with least bit error rate and observes weather it is able to provide the required data rate in LTE systems.

title: A comparison study on the SNR values by using digital modulation schemes with multiple fading channels
abstract: Signal to noise ratio is used as an indicator for evaluating the quality of communication. Due to this feature it is very important to estimate the SNR value for the modern wireless communication. In this paper a comparison study on the SNR value for different modulation schemes through fading channels is proposed. The proposed estimator is moment based one and performance evaluated on different channel conditions. For the performances analysis an expression for the moments of the received signals be developed .Modulation schemes like bipolar phase shift keying (BPSK) Quadrature amplitude modulation (QAM) and quadrature phase shift keying (QPSK) are performed for the SNR estimator. This estimator works on Additive White Gaussian Noise AWGN, Nakagami and Rayleigh fading channels. The existing model SNR estimation methods were degraded for higher level modulation scheme. As an extension we propose a moment based SNR estimator for different modulation scheme using AWGN, Rayleigh and Nakagami. Results provide that proposed estimator works better in low SNR conditions which are applicable to different communication scenarios.

title: Bit Error Rate (BER) Comparison of AWGN Channels for Different Type's Digital Modulation Using MATLAB Simulink
abstract: The MATLAB software with relevant Toolboxes for developing Simulink model is used for the simulation of system. In this paper, three basic types of digital modulation techniques are discussed then the bit error rate performance characteristics of receiver are evaluated by using MATLAB Simulink model for FSK, PSK and QAM modulation techniques. There are various kinds of channel used in wireless communication In this paper, the AWGN channel is used between transmitter and receiver. This paper focuses on the characterization and the design of analog signal waveforms that carry digital information and compares their performance on an AWGN channel.

title: Reliability Checking for Digital Modulation Schemes in 4G 5G Communication system: Comparison between QPSK and QAM Modulation Techniques for Beyond LTE
abstract: In recent days, there have been a race among the communication systems in different schemes and generations. Day by day the data transmission rate is increasing and breaking the record of previous generations. Now, people are thinking of transmitting data beyond imagination. Also, engineers and scientists are also stepping forward for transmitting in a huge range of data. In recent times, 4th Generation and 5th Generation communication system are on transitional state. 4th Generation is almost getting replaced with 5th Generation communication architecture. For LTE and beyond LTE communication system several types of digital modulation schemes are used. Among them QPSK and QAM are quite frequently used. In this research paper, comparative analysis over simulation in a virtual environment (Simulink Based) for these two types of digital modulation schemes in 4G and beyond 4G communication architecture. In both of the cases, BER (Bit Error Rate) with respect to SNR (Signal to Noise Ratio) have been compared for the better and efficient output.

title: Performance Comparison of Radio over Fiber System Using WDM and OADM with Various Digital Modulation Formats
abstract: Radio over Fiber (RoF) is a technology where light is modulated with radio frequency signals and transmitted over the optical fiber to facilitate wireless access and transmission. The convergence of wired and wireless networks is a promising solution for the increasing demand of transmission capacity and flexibility, as well as offering economic advantages due to its broad bandwidth and low attenuation characteristics. The full duplex transmission of RoF is accomplished by means of Wavelength Division Multiplexing (WDM) and Optical Add Drop Multiplexer (OADM) where WDM enables transmission of different signals through a single mode fiber over large distance and OADM permits transmission of both down link and uplink data via the same single mode fiber. The performance analysis of RoF system employing various line coding techniques and digital modulation formats has also been done. The simulation and performance comparison of RoF was done using Optisystem 12.0.

title: Realization of Multi Modulation Schemes for Wireless Communication by Time Domain Digital Coding Metasurface
abstract: Metasurfaces are well designed artificial periodic or quasiperiodic structures to achieve customized electromagnetic responses. Based on the time domain digital coding metasurface (TDCM) with dynamic reflection or transmission characteristics, one can realize direct information modulation on the metasurface, which has been used in wireless communications. In comparison with the classical architectures of wireless communication systems, the TDCM has advantages for simple architecture, easy manufacture, and low cost. However, the wireless communication systems based on the TDCM are still limited by low conversion efficiency, spectrum pollution, and hard to implement high order modulation schemes. To solve these limitations, we propose a new route to achieve multi modulation schemes in wireless communications by regulating the reflection phases of the TDCM in a nonlinear way. By carefully designing the regulation voltages applied to the diodes on TDCM, arbitrary constellation diagrams are successfully synthesized. The novel systems can implement various modulation schemes such as quadrature phase shift keying (QPSK) 8PSK, and 16QAM with good communication quality, high stability, and free scheme switching. The presented method may find important applications in modern wireless communication technologies.