The term noise refers to unwanted electrical signals that are always present in electrical systems and the term additive means the noise is superimposed or added to the signal that tends to obscure or mask the signal where it will limit the receiver ability to make correct symbol decisions and limit the rate of information transmission. Thus, it has driven many researches into the application of higher order modulations. Moreover, errors can be easily produced as the number of users is increased and the mobile terminal is subjected to mobility. Modulation schemes which are capable of delivering more bits per symbol are more immune to errors caused by noise and interference in the channel. When a large amount of power is available, it is easy to reduce the bandwidth of a modulation scheme similarly high power is not needed to achieve a low BER if a wide bandwidth can be tapped. High data rate like 8-PSK can transmit 3 bits per symbol. Bit Error Rate (Pb) = Number of bit in error Total number of transferred bits The performance of each modulation is measured by calculating its probability of error with assumption that systems are operating with additive white Gaussian noise. The bit error probability Pb is the expectation value of the BER. BER is a unit less performance measure often expressed as a percentage. The bit error rate or bit error ratio (BER) is the number of bits in error divided by the total number of transferred bits during a studied time interval. In Digital transmission the number of bit errors is the number of received bits of a data stream over a communication channel that has been altered due to noise, interference, distortion or bit synchronization errors. The BER curves for MPSK obtained after simulation are compared with theoretical curves. Error rates of M- ary PSK system versus the signal-to-noise ratio (SNR) are used to evaluate the performance of M-ary PSK system.
This paper indicates that increasing of M results in increase of BER.
To better understand the M-ary PSK system, a Simulink-based simulation system is designed for M-ary PSK for M=2, 4 and 8 using communication toolbox in Simulink. It focuses on comparative performance analysis of basic M-ary PSK modulation schemes like BPSK (M=2). General explanation for probability of error is explained and simulated in this paper. Each modulation technique has different performance while dealing with signals, which normally are affected with noise.
It is important to analyze the system in term of probability of error to view the system's performance. I N digital communication system design, the main objective is to receive data as similar as the data sent from the transmitter. Keywords - Additive Gaussian Noise, Bit error Rate, M-ary Phase Shift Keying, Signal-to-Noise Ratio. Through this technique we have analyzed and calculated probability of error with systems opera ting with the additive white Gaussian noise and by doing so the performance of modulation techniques can be compared with theoretical values. And Technology/Electronics and Communication, Mohali, Punjab, IndiaĪbstract - In this paper the bit error rate (BER) analysis of binary phase shift keying (BPSK) modulated signal detection is performed in presence of additive white Gaussian noise. International Journal of Scientific & Engineering Research, Volume 3, Issue 6, June-2012 1 Optimization Method for Analysis of Bit Error Rate with BPSK Modulation Technique
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