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Now a days digital communications is widely used in telecommunication sector, in this the information is coded in the form of bits. There are many techniques for modulation in digital communication as BPSK, QPSK, M-ary PSK, GMSK and many more. While transmitting an image there is challenge to retain the quality of an image by using these digital modulation techniques. In this paper there is use of...
In this paper, we consider the multicast resource allocation problem for video streaming in Orthogonal Frequency Division Multiple Access (OFDMA) systems. The video streams are encoded into base layer (BL) and enhancement layer (EL) data by the hierarchical video coding (HVC) scheme. The basic resource unit is a set of contiguous subcarriers (chunk). The problem is formulated to maximize the sum of...
This work presents a first common gate continuous time linear equalizer (CG-CTLE) with charge mode adaptation in 1.1 V, 65 nm CMOS technology. The proposed equalizer is realized with a common gate topology and offers an input impedance of 50 Ω. It also acts as a first stage of current modereceiver and is made adaptive to varying channel loss. Therefore, the need for an external...
This paper presents a fully integrated optical receiver for On-Off-Keying (OOK) visible-light communication (VLC) links. The circuit is implemented in AMS 0.35μm technology, with the OPTO process option allowing for high-quality photo-detectors integration. The implemented receiver exhibits a low input referred noise density of 5 pA/VHz to meet the sensitivity requirements of free-space optical wireless...
Ultra-high data rate is required for future cloud computing and interconnects systems, for which integrated optical transceivers provide promising solutions. We report 66 Gb/s, on-off keying (OOK) operation of a silicon microring modulator (MRM) consuming a low power of 15 fJ/bit. To the best of our knowledge, this result features the fastest binary shift keying operation using a MRM.
Inter-symbol interference (ISI) in visible light communication (VLC) systems has been considered as a major problem that seriously deteriorates system performance. A series of equalization algorithms have been widely investigated and utilized to eliminate ISI and improve the system performance. In this paper, we propose a novel algorithm called scalar modified cascaded multi-modulus algorithm (S-MCMMA)...
A broad range of emerging applications require very low power, very long range yet low throughput communication. Different standards are being proposed to meet these novel requirements. In this paper, the technical differences between a wideband spread spectrum (LoRa-like) and an ultra narrowband (Sigfox-like) network will be explained and evaluated. On the physical layer, simulation results show...
Orthogonal Frequency Division Multiplexing (OFDM) is designed to combat the effect of multipath reception, by dividing the wide band frequency selective fading channel into many narrow flat sub- channels, which improves the spectral efficiency and significantly mitigates the intersymbol interference (ISI). However, OFDM can not meet the demand for 5G heterogeneous service scenarios since it has a...
Communication system performance under jamming can be analyzed in most cases if the jamming hit rate (the percentage of jammed bits) is known or could be estimated. Radar electronic warfare (EW) engineers have used the theory of coincidence of pulse trains for similar situations with success. However, the theory does not hold for communications in all scenarios, especially if a fast sweeping (or stepping)...
In practical underwater wireless optical communications (UWOC), pulse modulation technique has been widely used due to the high optical power efficiency and relatively low system complexity. Compared with the simplest on-off keying (OOK) scheme, digital pulse interval modulation (DPIM) improves both power efficiency and error performance and requires no symbol synchronization. Polarization shift keying...
A multi-service (MS) code based Spectral Amplitude Coding-Optical Code Division Multiple Access (SAC-OCDMA) system at different number of basic user, typically suitable for video, audio and data transmission is experimentally investigated. The work is carried out to show the feasibility of the previous work that has been demonstrated using mathematical computation. The obtained results indicate that...
Underwater acoustic modems are normally considered to offer low data-rates over distances of a few kilometers. This paper reports on open water performance of a high-frequency acoustic modem with demonstrated data rates of 380 kbps. The modem is simple and runs on commodity hardware using well understood signaling techniques.
High-speed signaling over package substrates is key to delivering the promise of 2.5D integration. Applications abound and include high-density memory interfaces, sub-division of large dies to increase yield and lower development time, sub-division of a die to achieve upward or downward scalability, or connecting to an off-chip SerDes or optics engine. Each of these in-package applications typically...
In this paper, a digital closed-circuit television (CCTV) transmission system called the extended reach high definition serial digital interface (ER-SDI) is proposed to improve the transmission distance while preserving the quality. The current standard of HD-serial digital interface (HD-SDI) has the maximum transmission distance of 200 m. The proposed ER-SDI provides a transmission distance of 518...
Not long ago, the significance of underwater wireless optical communication has been developed for utilization of submerged investigation and ocean audit arrangements. This Undersea Wi-Fi visual connection technology is normal to play a predominant act in inspecting climate changes, prediction of natural crashes, and discovery of natural resources, marine biology, sea, and ocean environment. This...
In digital communication technique the most important issue is to receive data at receiver side similar to the data send from the transmitter side with a high speed using fewer channel bandwidth. This means that it is very important to test the systems in terms of probability of error P(e) to observe the system's performance. Each modulation technique has different performance while dealing with signals,...
Wireless Transmission of a speech signal with low Bit Error Rate is one of the major challenges in Communication Systems particularly in cellular environment. In this paper a new technique to evaluate the performance of coded speech at a low data rates using Linear Predictive Coding (LPC) and Quadrature Phase Shift Keying (QPSK) modulation has been realized and simulated. A test recorded speech signal...
Analysis is presented for a UWB RFID communication system using the technique of multi-band OFDM without and with reader receiver diversity. The analysis is provided to find the expression of the bit error rate (BER) of MB-OFDM UWB RFID link with number of receiving antenna at the reader with M-array PAM. BER results are evaluated for indoor industrial UWB environment using several values of MB-OFDM...
The centrality of interleavers in interleave-division multiple-access (IDMA) cannot be over-emphasised, the interleaver being the only means of isolating signals for different users of the multiple-access system. This work gives a critical review of bit-error-rate (BER) performance of interleavers and IDMA systems. Existing literature shows that there are disagreements among results published by different...
The effect of interaction between fiber dispersion and nonlinearities in DWDM hybrid optical communication system is investigated. Eight DWDM wavelengths, 100-GHz spaced chosen on ITU-grid were used in the study. Different hybrid configurations of 10 Gbps and 40 Gbps signals were considered. Numerical simulations were conducted to predict the performance of each signal transmitted. Bit-error-rate...
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