Exact BER computation of generalized hierarchical PSK constellations

The optical ZCZ code, which is a set of pairs of binary and biphase sequences with zero correlation zone, can provide code division multiple access (CDMA) communication system without co-channel interference. The M-ary amplitude shift keying spread spectrum (M-ary/ASK-SS) system using this code can detect a desired sequence without interference of undesired sequences. We have proposed the compact construction of a matched filter bank for this code, which is called the compact-type matched filter bank. However, M-ary/ASK-SS system using this filter bank might go down the bit error rate (BER) performance because input-output characteristics of this filter bank for this code with zero correlation zone 4n - 2 are nonlinear characteristics. In this paper, we clarify that BER performance in the M-ary/ASK-SS system over the additive white Gaussian noise (AWGN) channels is not influenced by nonlinear characteristics of this filter bank by the theoretical formula of BER characteristics and the computer simulation. The BER performance in the ASK-SS system using compact-type matched filter under the AWGN environment go down compared to that using direct-type matched filter as expected. But the BER performance in the M-ary/ASK-SS system using this compact-type matched filter bank under the AWGN environment is almost equal compared to that using parallel-type matched filter bank. In fact, this compact-type matched filter bank is effective in the M-ary/ASK-SS system.

Recently, the differential detection scheme has attracted considerable attention as a demodulated scheme for digital mobile communications because of its robustness in the frequency nonselective fading channel. A problem of the differential detection scheme is that its bit error rate (BER) performance in the additive white Gaussian noise (AWGN) channel is inferior to that of the coherent detection scheme. To solve this problem, many methods to improve BER performance of the differential detection in the AWGN channel have been proposed. However, those methods require complex signal processings.This paper proposes a novel differential detection scheme as a simpler improvement method which estimates the differential phase of the transmitted signal by a sequence estimation scheme using the Viterbi algorithm. The proposed scheme is simplified in a manner such that its signal processing is composed of only additions and subtractions on the phase information of the received signal. Results of computer simulation show that BER performance of the proposed scheme is close to that of the ideal coherent detection in the AWGN channel. In addition, the trellis diagram of the Viterbi algorithm can be reduced without performance degradation introducing the signal processing similar to the Scarece State Transition (SST) type Viterbi decoding. The proposed scheme also is useful in the case of the fast Rician fading channel and the slow Rayleigh fading channel.

Multipath fading in HF channels causes time-delay spread that limits the maximum symbol rate, and frequency selective fading that attenuates some frequency bands compared to others. Multi-carrier modulation techniques, multi-carrier ASK (MCASK) and multi-carrier PSK (MCPSK), can be used to ensure reliability of transmission and high data transmission rate. The bit-error rate (BER) performance is compared between single frequency modulation such as amplitude shift-keying (ASK) or phase shift-keying (PSK) and the multi-carrier modulation in the presence of additive white Gaussian noise and a combination of multipath fading and additive white Gaussian noise. On the average, the BER performance is better for the multi-carrier modulation compared to the single carrier modulation under multipath fading conditions.

The WiMax (Worldwide Interoperability for Microwave Access) is a technology in<strong> </strong>broadband wireless access, which employs OFDM (Orthogonal Frequency Division Multiplexing) as an alternative transmission to enable high speed data in communication system. This research aim is to analyze the performance system of the OFDM-Based WiMAX, which used the cyclic prefix. The model was designed in four schemes of simulation method, the BPSK (Binary Phase Shift Keying, QPSK (Quadrature Phase Shift Keying), 16 QAM (Quadrature Amplitude Modulation) and 64 QAM. Each scheme was investigated BER (Bit Error Rate) on AWGN (Additive White Gaussian Noise) channel and multipath Rayleigh fading channel, which had applied the cyclic prefix. By simulation of the cyclic prefix was produced the modulation measurement of the BPSK, QPSK, 16 and 64 QAM. The performance result of Eb/No 15 dB was obtained the BER of BPSK and QPSK of 1.11E-11, the BER of 16 QAM and 64 QAM of 8.69E-06 and 0.00333 respectively. Those results indicated much smaller BER value than EbNo 0 dB which BPSK and QPSK of 1 BER, 1.5 and 1.75 BER for 16 QAM and 64 QAM respectively. In conclusion, a higher value of EbNo, hence the BER value would be lower.

Phase shift keying modulation approaches are widely used in the communication industry. Differential phase shift keying (DPSK) and Offset Quadrature phase shift keying (OQPSK) schemes are chosen to be investigated is multi environment channels, where both systems are designed using MATLAB Simulink and tested. Cross talk and unity of signals generated from DPSK and OQPSK are examined using Cross-correlation and auto-correlation, respectively. In this research a proposed system included improvement in bit error rate (BER) of both systems in the additive white Gaussian Noise (AWGN) channel, by using the convolutional and block codes, by increasing the ratio of energy in the specular component to the energy in the diffuse component (k) and the diversity order BER in the fading channels will be improved in both systems.

Bit-interleaved coded modulation (BICM) transceivers often use equally spaced constellations and a random interleaver. In this paper, we propose a new BICM design, which considers hierarchical (nonequally spaced) constellations, a bit-level multiplexer, and multiple interleavers. It is shown that this new scheme increases the degrees of freedom that can be exploited in order to improve its performance. Analytical bounds on the bit error rate (BER) of the system in terms of the constellation parameters and the multiplexing rules are developed for the additive white Gaussian Noise (AWGN) and Nakagami-m fading channels. These bounds are then used to design the BICM transceiver. Numerical results show that, compared to conventional BICM designs, and for a target BER of 10^{-6}, gains up to 3 dB in the AWGN channel are obtained. For fading channels, the gains depend on the fading parameter, and reach 2 dB for a target BER of 10^{-7} and m=5.

Non-orthogonal multiple access (NOMA) is one of the potential future mobile network methods that can give better spectral efficiency, huge connectivity, and low latency. As a result, academic and industry researchers have studied the error performances and capacity of NOMA systems. The main drawback of NOMA methods is user interference, which is generally addressed by interference cancellation techniques such as Successive Interference Cancellation (SIC) at receivers. Therefore, it is better to obtain the bit error rate (BER) performance of NOMA. Each user's power level is determined by the power level assigned to them. As a result, this work presents BER analysis for two NOMA users using BPSK modulation in additive white Gaussian noise (AWGN), Rayleigh, and Rician fading channels. Initially, we assessed BER performance for various Signal to Noise Ratio (SNR) values by assuming two users who are equally spaced from the base station (BS). Later, the BER performance for various transmit powers is assessed by assuming two users are situated at varying distances from the BS. The performances are discussed using MATLAB simulations. The comparative BER analysis is also studied for various fading environments.KeywordsBERNOMABPSKSICFading

This paper presents the performance analysis of compound chaotic sequence (CCS)-based noise reduction differential chaos shift keying (NR-DCSK) system under multipath Rayleigh fading channel conditions. The special characteristics of chaotic sequences are their deterministic randomness behaviour that adds security and multipath immunity to the data when used as a carrier in communication systems. In this paper, the chaotic sequences are generated by combining the outputs of chaotic maps, such as logistic map, Chebyshev map, Bernoulli shift map, tent map, etc., leading to new complex sequences known as CCSs. This sequence possesses more randomness, overcomes severe interference levels encountered during transmission and provides higher multipath immunity compared with those of pseudo-noise (PN) codes. Since NR-DCSK is a spread spectrum technique, its performance in wireless multipath fading channels has important considerations. The CCS is used as a carrier in NR-DCSK systems, which leads to improved bit error rate (BER) performance. Comparisons of simulation results to theoretical BER expressions of additive white Gaussian noise (AWGN) and Rayleigh fading channels have been carried out to test the efficiency of the proposed CCS-based NR-DCSK system.

The effects of multipath fading and additive white Gaussian noise (AWGN) on the bit error rate (BER) performance of direct-sequence code-division multiple-access (DS-CDMA) systems is studied in this paper. The expression for the conditional BER, conditioned on a given level of fading is derived and then the unconditional BER is evaluated. The BER performance results of the system are evaluated in a fading channel for different magnitude of fading. The proposed approach is also extended to estimate the BER performance of the CDMA system having multiple receiving antennas. The effectiveness of the selection method and maximal ratio combining (MRC) method as diversity combining schemes are investigated and compared. To enhance the system performance channel coding is also applied to the system.

The UMTS Long Term Evolution (LTE) is an emerging technology in the evolution of 3G networks. LTE runs on an advancement of the obtainable UMTS infrastructure already used by over 80 percent of mobile subscribers worldwide. We have very inadequate resources in cellular technologies and it is important to utilize them with high efficiency. Single Carrier Frequency Division Multiple Access (SC-FDMA) & Orthogonal Division Multiple Access (OFDMA) are most important division of LTE. OFDMA was well utilized for achieving high spectral efficiency in communication method. SC-FDMA is introduced in recent times and it became handy candidate for uplink multiple access scheme in LTE system that is a project of Third Generation Partnership Project (3GPP). The Multiple Access Scheme in Advanced Mobile radio system has to meet the challenging requirements for example high throughput, fine robustness, capable Bit Error Rate (BER), high spectral efficiency, small delays, low computational difficulty, less Peak to Average Power Ratio (PAPR), low error probability etc. In our paper, we investigate the performance of SC-FDMA in LTE physical layer by considering different modulation schemes (QPSK, 16QAM and 64QAM) on the basis of BER vs Eb/No. Additive White Gaussian Noise (AWGN) and fading channel are used to evaluate the performance in presence of noise and fading.

This article investigates the comparative between the Bit Error Rate (BER) performance of Phase Shift Keying (PSK) and quadrature amplitude modulation (QAM) based on Space Time Block Coded Orthogonal Frequency-Division Multiplexing based on Discrete Framelet transform (STBC-FT-OFDM) system. This comparison is accomplished through simulation programs for different constellation points numbers for M-PSK and M-QAM (M = 4, 16, and 64) over an Additive White Gaussian Noise (AWGN), and Rayleigh multipath fading channels. The simulation results showed that the M-QAM modulation technique gave preferable BER performance compared with M-PSK modulation technique at all cases of constellation points and channels.

In this chapter, bit error rate (BER) performance of some of digital modulation schemes and different wireless communication techniques is evaluated in additive white Gaussian noise (AWGN) and fading channels. Further, the BER performance of different diversity techniques such as selective diversity, EGC, and MRC is also evaluated in Rayleigh fading channel.

Performance of both orthogonal frequency division multiplexing (OFDM) and single carrier (SC) systems suffers from a carrier frequency offset (CFO) due to Doppler effect and the carrier instability between the transmitter and the receiver. We investigate the bit error rate (BER) performance degradation of OFDM and SC systems due to the frequency offset in an additive white Gaussian noise (AWGN) channel as well as multipath Rayleigh fading channels. We consider three effects to the BER degradation, i.e., phase shift, useful power decrease and intercarrier interference (ICI). We also derive the approximate expressions of BER under binary phase shift keying (BPSK) and quaternary phase shift keying (QPSK) for both OFDM and SC systems in the presence of CFO. In general, SC is more robust to CFO in the AVVGN channel than OFDM in terms of BER, while both of them suffer similarly from CFO in the multipath Rayleigh fading channels assuming the the same CFO.

An underwater acoustic multimedia communication (UWAMC) system is proposed with 2400 transmission modes according to time-varying multipath underwater acoustic (UWA) channel conditions. The orthogonal variable spreading factor (OVSF) scheme and Gold sequence (GS) scramble code are integrated into multi-input multi-output UWAMC system based on orthogonal frequency-division multiplexing to achieve the quality of service of multimedia transmission in the UWA channel. Binary phase shift keying (BPSK) and quadrature phase shift keying (QPSK) adaptive modulation, direct mapping (DM) or space–time block code (STBC) transmission strategies, convolution channel code with rate 1/2 and 1/3, and a power assignment mechanism were adopted in the proposed system. Simulation results show that the bit error rate (BER) and power saving ratio (PSR) performance of the STBC strategy with transmission diversity is superior to that of the DM strategy without transmission diversity, and the performance of the BERs and PSRs of the transmission scheme with the GS scramble code surpasses that of the scheme without the code. The performance of the BERs and PSRs of BPSK modulation with a channel code rate of 1/3 is better than that of BPSK modulation with a channel code rate of 1/2, and the performances of BERs and PSRs of BPSK modulation with a channel code rate of 1/3 are better than that of QPSK modulation with a channel code rate of 1/3. As the length of the OVSF codes increases, the UWAMC system’s BERs decrease, and its PSRs increase. The UWAMC system can achieve either maximum transmission speed or maximum transmission power efficiency.

Bit-error rate (BER) performance analyses are presented for Reed-Solomon coded fast frequency-hopping binary frequency-shift-keying (FFH/BFSK) spread-spectrum (SS) systems under the conditions of additive white Gaussian noise (AWGN) and the worst-case band multitone jamming (MTJ). The FFH system employs the soft-decision linear-combining receiver to obtain the diversity-combining output. The corresponding hard decision of the diversity-combining output is then used to decode the Reed-Solomon codes. The analytical expressions of the BER performance of the coded FFH systems are derived and shown to be applicable to higher diversity levels without much more computational complexity. Numerical results show that there is an optimum code rate for the Reed-Solomon coded system under the worst-case multitone jamming conditions.