scholarly journals Approximate minimum bit-error rate equalization for pulse-amplitude and quadrature-amplitude modulation

2002 ◽  
Author(s):  
Chen-Chu Yeh ◽  
J.R. Barry
Keyword(s):  
Bit Error Rate ◽  
Error Rate ◽  
Amplitude Modulation ◽  
Pulse Amplitude ◽  
Quadrature Amplitude Modulation

scholarly journals Performance Evaluation of PAM-4 and PAM-2 Modulation Techniques using MATLAB

2018 ◽  
Vol 3 (5) ◽  
pp. 36
Author(s):  
Waliu Olalekan Apena
Keyword(s):  
Bit Error Rate ◽  
Error Rate ◽  
Amplitude Modulation ◽  
Pulse Amplitude ◽  
Data Rate ◽  
Pulse Amplitude Modulation ◽  
Eye Diagram ◽  
Modulation Technique ◽  
Modulation Techniques ◽  
Four Levels

Two Levels Pulse Amplitude Modulation techniques (PAM-2) is failing to cope with the increase in appetite for data and higher data rate with respect to noisy channel. Hence, Four Levels Pulse Amplitude Modulation techniques (PAM-4) was developed. PAM-4 is said to enable two times the data rate as compared to PAM-2. PAM-4 has its pros and cons as compared with PAM-2. This paper compares the performance of Two Levels Pulse Amplitude Modulation technique to Four Levels Pulse Amplitude Modulation technique. The communication system was modeled using Simulink R2016b, the signal passed through an Additive White Gaussian Noise (AWGN) Channel and eye diagram scope was adopted to evaluate the corresponding signal. The study compared eye diagram to evaluate both PAM-2 and PAM-4 at same channel condition. Bit error rate (BER) analysis of the two signals were studied and the results for the corresponding signals were compared. It was observed that the performance of PAM-2 surpasses PAM-4 in terms of the bit error rate analysis. The study shows similar characteristic for Symbol Error Rate Probability curve. The result revealed that PAM-4 is more susceptible to noise than PAM-2.

scholarly journals Performance Analysis, Characteristics, and Simulation of Digital QAM

2017 ◽  
Vol 1 (1) ◽  
Author(s):  
Nikolaos Voudoukis
Keyword(s):  
Performance Analysis ◽  
Bit Error Rate ◽  
Error Rate ◽  
Amplitude Modulation ◽  
Performance Indicators ◽  
Digital Transmission ◽  
Quadrature Amplitude Modulation ◽  
Radio Communications ◽  
Awgn Channel ◽  
Data Rates

Quadrature Amplitude Modulation or QAM is a form of modulation which is widely used for modulating data signals onto a carrier used for radio communications. QAM, when used for digital transmission for radio communications applications is able to carry higher data rates than ordinary amplitude modulated schemes and phase modulated schemes. This paper presents the various fields where QAM can be implemented, describes modulator/demodulator block diagrams for transmitters as well as receivers, provides an introduction of certain performance indicators of modulation and a list of applications using alternative implementations of QAM. Also the paper presents a simulation of QAM using Simulink (example of 16-QAM signal) with signal trajectors and constellation plots. It is compared the theoretical and simulated Bit Error Rate (BER) for 16-QAM with Gray coding in an AWGN channel. Some general conclusions are also cited.

scholarly journals Moment-Based Analysis of Reg. Triangular QAM in Turbulent Atmospheric Channels with Pointing Errors incorporates Zero and Non-zero Boresight

2020 ◽  
Author(s):  
Muhammad Nabeel Shahid ◽  
Furqan Haider Qureshi ◽  
Shahzad Amin Sheikh ◽  
Qasim Umar Khan ◽  
Muhammad Zeeshan
Keyword(s):  
Atmospheric Turbulence ◽  
Error Rate ◽  
Amplitude Modulation ◽  
Communication Systems ◽  
Symbol Error Rate ◽  
Quadrature Amplitude Modulation ◽  
Optical Beam ◽  
Beam Radius ◽  
Pointing Errors ◽  
Average Symbol Error Rate

Abstract In recent years, free-space optical (FSO) technology has gained fame in communication systems due to its high data rates and license-free feature. Triangular quadrature amplitude modulation (TQAM) is an efficient modulation scheme that uses even bits per symbol, and it has a low average symbol error rate (ASER) than square quadrature amplitude modulation (SQAM). In this paper, we theoretically investigate the performance of subcarrier triangular quadrature amplitude modulation (SC-TQAM) corrupted by atmospheric turbulence in the presence of pointing errors (P.E) in FSO communications. We have considered boresight displacement, P.E effect, and atmospheric turbulence. To represent the atmospheric turbulence we consider Log-normal, Rayleigh and Rician distributions which exhibit weak, moderate and strong weather effects. The P.E is employed using Rayleigh and Rician distribution that incorporates zero and non-zero boresight displacement respectively. The moment generating functions of these models have been derived. P.E is modeled using an optical beam radius and receiver aperture radius. The combination of these parameters will help enhance the average symbol error rate (ASER). Furthermore, we have derived an analytical expression that is used to develop numerical results. The ASER performance is observed against average received irradiance, optical beam radius, P.E standard deviation and receiver aperture radius. In the end, the ASER performance is evaluated against SNR and Monte Carlo simulations are performed which validates the theoretical results.

scholarly journals Exact Bit Error-Rate Analysis of Two-User NOMA Using QAM with Arbitrary Modulation Orders

2020 ◽  
Author(s):  
Arafat Al-Dweik ◽  
Tasneem Assaf ◽  
Mohamed El Moursi ◽  
Hatem Zein El din ◽  
Mohammad Al-Jarrah
Keyword(s):  
Closed Form ◽  
Power Allocation ◽  
General Expression ◽  
Bit Error Rate ◽  
Error Rate ◽  
Amplitude Modulation ◽  
Interference Cancellation ◽  
Multiple Access ◽  
Rate Analysis ◽  
Multiuser Detector

This work considers the exact bit error rate (BER) analysis of a two-user non-orthogonal multiple access (NOMA) system using quadrature amplitude modulation (QAM). Unlike existing work, no constraints on the modulation order of the QAM symbols for any user. Closed-form expressions are derived for the BER of joint multiuser detector (JMuD), which is demonstrated that it is equivalent to the successive interference cancellation (SIC) receiver. Moreover, a general expression is derived for the relation between the power allocation factors for the two users, which depends on the modulation order for each user.

scholarly journals An Investigation of the Impacts of Phase Noise on Symbol Error Rate in Quadrature Amplitude Modulation Systems

2018 ◽  
Vol 3 (1) ◽  
Author(s):  
Hilary U Ezea ◽  
Kehinde Adebusuyi ◽  
Temidayo Ofusori ◽  
Rita U Ezea
Keyword(s):  
Phase Noise ◽  
Error Rate ◽  
Amplitude Modulation ◽  
Symbol Error Rate ◽  
Quadrature Amplitude Modulation ◽  
Soft Decision ◽  
Matlab Simulation ◽  
System Complexity ◽  
Soft Decision Decoding ◽  
The Impact

The existence of phase noise in virtually every digital communications system poses a serious challenge to system designers especially as system complexity increases. Communication system complexity could be attributed to the modulation techniques adopted and the circuitry employed in achieving such modulations. This work investigates the impact of phase noise on the Symbol Error Rate (SER) of the different Quadrature Amplitude Modulation (QAM) schemes.  MATLAB simulation technique is adopted for the work and the results of the simulations show that as the phase noise is increased negatively, all the QAM schemes investigated show a reduction in SER and at a point, records a zero error. The value at which the schemes record this zero symbol error rate increases as the complexity of the scheme increases. So, higher order QAM schemes accommodate more symbol errors than the lower orders. The results also show that hard decision decoding has the worst performance index, irrespective of the QAM scheme, when compared with soft decision decoding.

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