Waveform Design for Energy Efficient OFDM Transmission

In this chapter, a green radio transmission using the binary phase-shift keying (BPSK) modulated orthogonal frequency-division multiplexing (OFDM) signal is addressed. First, the OFDM transmission signal is clearly stated. For a specified performance of the system, the least transmit power occurs by the optimal OFDM shape, which is designed to minimize the average inter-carrier interference power taking into account the characteristic of the transmit antenna and the detection process at the receiver. The optimal waveform is obtained by applying the calculus of variations, which leads to a set of differential equations (known as Euler equations) with constraint and boundary conditions. Results show the transmission effectiveness of the proposed technique in the shaping of the signal, as well as its potential to be further applied to smart context-aware green wireless communications.

Perancangan Model Simulator dan Performansi Kesalahan Bit untuk Variasi Tipe Modulasi Digital Dalam Lingkungan Kanal Additive White Gaussian Noise (AWGN)

Penelitian ini dibuat berdasarkan permasalahan pada penelitian sebelumnya, dimana belum menampilkan gelombang sinyal sesudah melewati kanal Additive White Gaussian Noise (AWGN), serta menampilkan hasil simulasi perbandingan kesalahan bit yang ditampilkan dalam bentuk grafik kurva untuk berbagai tipe modulasi. Selain itu gelombang sinyal probabilitas kesalahan bit masih ditampilkan terpisah serta belum melakukan analisa antara perhitungan dengan hasil simulasi. Maka pada penelitian ini akan dilakukan pengembangan pada source code dan juga dibuatnya graphical user interface (GUI) Matlab beserta dengan perhitungan teoritisnya. Pada hasil simulasi jumlah bit minimal sebesar 100 bit didapatkan untuk modulasi amplitude Shift Keying (ASK), untuk modulasi frekuency shift keying (FSK) dan untuk binary phase shift keying (BPSK). Sedangkan pada jumlah bit maksimum bit sebesar 500 bit didapatkan untuk modulasi ASK, untuk modulasi FSK, dan untuk modulasi BPSK. Dari dua data tersebut menunjukan bahwa data simulasi sudah sesuai dengan teori yang ada, dimana semakin besar energi bit yang digunakan maka bit error rate (BER) yang dihasilkan akan semakin kecil. Kesesuaian simulasi dengan teori didukung juga oleh hasil perhitungan probabilitas kesalahan bit. Hasil simulasi dan teoritis probabilitas kesalahan bit memiliki karakteristik yang sama, dimana modulasi BPSK memiliki penurunan probabilias kesalahan bit yang lebih kecil dibandingkan modulasi ASK dan FSK. Selain itu didapatkan bahwa hasil perhitungan mengalami penurunan kesalahan bit yang lebih kecil serta ideal pada Eb/N0 yang sama untuk setiap percobaannya.

Application of Ultra Narrow Band Modulation in Enhanced Loran System

The Enhanced Loran (eLoran) system is valued for its important role in the positioning, navigation, and timing fields; however, with its current modulation methods, low data rate restricts its development. Ultra narrow band (UNB) modulation is a modulation method with extremely high spectrum utilization. If UNB modulation can be applied to the eLoran system, it will be very helpful. The extended binary phase shift keying modulation in UNB modulation is selected for a detailed study, parameters and application model are designed according to its unique characteristics of signal time and frequency domains, and it is verified through simulation that the application of this modulation not only meets the design constraints of the eLoran system but also does not affect the reception of the respective signals of both parties. Several feasible schemes are compared, analyzed, and selected. Studies have revealed that application of UNB modulation in the eLoran system is feasible, and it will increase the data rate of the system by dozens of times.

Exact BER Analysis of NOMA with Arbitrary Number of Users and Modulation Orders

<div><div>Non-orthogonal multiple access (NOMA) is a promising candidate for future mobile networks as it enables improved spectral-efficiency, massive connectivity and low latency. This paper derives exact and asymptotic bit error rate (BER) expressions under Rayleigh fading channels for NOMA systems with arbitrary number of users and arbitrary number of receiving antennas and modulation orders, including binary phase-shift keying and rectangular/square quadrature amplitude modulation. Furthermore, the power coefficients' bounds, which ensure users' fairness, and solve the constellation ambiguity problem, are derived for N=2 and 3 users cases with any modulation orders. In addition, this paper determines the optimal power assignment that minimizes the system's average BER. These results provide valuable insight into the system's BER performance and power assignment granularity. For instance, it is shown that the feasible power coefficients range becomes significantly small as the modulation order, or N, increases, where the BER performance degrades due to the increased inter-user interference. Hence, the derived expressions can be crucial for the system scheduler in allowing it to make accurate decisions of selecting appropriate N, modulation orders, and power coefficients to satisfy the users' requirements. The presented expressions are corroborated via Monte Carlo simulations.</div></div><div><br></div>

Simulasi Direct Sequence Spread Spectrum (DSSS) Pada Modulasi Binary Phase Shift Keying (BPSK)

Spread spectrum is a data transmission technique that spreads out information spectrum energy signals in a frequency band that is much larger than the minimal spectrum. One of the spread spectrum techniques is Direct Sequence Spread Spectrum (DSSS). This research was built the simulation of DSSS on Binary Phase Shift Keying (BPSK) modulation using MATLAB software. The simulation results of this DSSS simulation are displaying information wave signals, PN codes, signals that have been added with PN codes, signals modulated with BPSK, modulation signals that have been added with AWGN noise, demodulation signals, DSSS output signals and BER vs SNR graphics on the channel AWGN. The simulator of DSSS on BPKS in this research have been running according to the DSSS signal order flow and theoretical concept. Keywords: AWGN, BPSK , DSSS, PN Code, PN Sequence

A Millimeter-Wave CMOS Injection-Locked BPSK Transmitter in 65-nm CMOS

In order to provide gigabit per second wireless communication, various standards have been proposed and implemented in recent years. Since the millimeter-wave (mm-wave) communication enables uncompressed high-speed data transfer with a minimum delay, it is considered to be the most promising technology to alleviate the pressure of the increasing demand of the spectrum resource. In this paper, a compact and highly efficient mm-wave transmitter is presented. The proposed injection-locked binary phase-shift keying (BPSK) transmitter can deliver a 10.2 dBm output with an efficiency over 10%. The proposed transmitter occupies 0.105 mm2 chip area in 65 nm CMOS process.

Graphene-Based BPSK and QPSK Modulators Working at A Very High Bit Rate (Up Tbps Range)

We are presenting graphene-based Binary Phase Shift Keying (BPSK) and Quadrature Phase Shift Keying (QPSK) modulators, which can operate in the range from the TeraHertz up to the infrared. It is noteworthy that these devices have huge advantages over the silicon Mach-Zehnder optical modulators (MZMs) with lateral PN-junction ribwaveguide phase shifters. Among the countless advantages, we can mention, for example, that these modulators consist of only one waveguide and have a much simpler application system of the modulator signal (gate voltage) than in silicon-based MZMs. Other huge advantages are greater efficiency, and yet, they are cheaper and have shorter lengths (and consequently, greater integration in photonic integrated circuit (PIC)). The first step to present these modulators was to detail the graphene theory that is involved in this device. After this step, we show the project, numerical simulations, and analyses related to our graphene-based BPSK and QPSK modulators. We believe that these modulators will contribute to the generation of new devices made up of 2D materials, which should revolutionize this area of science.