High Quality Data Transmission Research Articles

High performance turbo encoder using mealy FSM state encoding technique

Error-correction Coding plays a vital role to obtain efficient and high quality data transmission, in today’s high speed wireless communication system. Considering the requirement of using high data rates by Long Term Evolution (LTE) system, parallel concatenation of two convolutional encoders were used to design turbo encoder. In this research task a high speed turbo encoder, which is a key component in the transmitter of wireless communication System, with memory based interleaver has been designed and implemented on FPGA for 3rd Generation Partnership Project (3GPP) defined Long Term Evolution – Advanced (LTE-A) standard using Finite state Machine(FSM) encoding technique. Memory based quadratic permutation polynomial (QPP) interleaver shuffles a sequence of binary data and supports any of the 188 block sizes from N= 40 to N= 6144. The proposed turbo encoder is implemented using 28nm CMOS technology and achieved 300 Mbps data rate by using 1% of available total hardware logic. By using the proposed technique, encoded data can be released continuously with the help of two parallel memories to write/read the input using pipelining concept.

Modelling of 10 Gbps Free Space Optics Communication Link Using Array of Receivers in Moderate and Harsh Weather Conditions

AbstractIntersymbol interference and attenuation of signal are two major parameters affecting the quality of transmission in Free Space Optical (FSO) Communication link. In this paper, the impact of these parameters on FSO communication link is analysed for delivering high-quality data transmission. The performance of the link is investigated under the influence of amplifier in the link. The performance parameters of the link like minimum bit error rate, received signal power and Quality factor are examined by employing erbium-doped fibre amplifier in the link. The effects of amplifier are visualized with the amount of received power. Further, the link is simulated for moderate weather conditions at various attenuation levels on transmitted signal. Finally, the designed link is analysed in adverse weather conditions by using high-power laser source for optimum performance.

High-Speed Wavelength Resource Reconfiguration System Concurrently Establishing/Removing Multiwavelength Signals

We propose a novel wavelength resource reconfiguration system with a wavelength selective switch (WSS) and our unique burst-mode erbium-doped fiber amplifier (BM-EDFA) for dynamic and agile new-generation optical networks such as an elastic optical network. The system can concurrently establish or remove multiwavelength channels, while preserving the system stability. In a conventional reconfiguration system, the processing time is increased in proportion to the number of the reconfigured wavelength channels because each wavelength channel is sequentially established or removed. On the other hand, in the proposed system, the multiwavelength channels would be simultaneously established or removed. Therefore, in principle, the processing time for reconfiguration of multiwavelength channels can be 1/(the number of the reconfigured channels) compared to the conventional system with sequential processing. In addition, the system can provide a further reduction effect of the processing time since the adjustment of variable optical attenuators of the WSS is unnecessary after establishing or removing multiwavelength channels. We had demonstrated a proof of concept using a reconfiguration system for the first time. The system employing flexible-grid WSSs and a BM-EDFA showed that the total processing time could be more than 100 s shorter in the case of removing four-wavelength channels with the high-quality data transmission.

Editorial: recent advances in communication networks and multimedia technologies

To successfully support multimedia applications, it is necessary to improve the state-of-theart multimedia technologies and multimedia transmissions over communication networks in order to provide quality-of-service (QoS) guarantees between end-users and to achieve a high quality-of-experience for end-users. The accepted papers in this special issue deal with a wide range of important aspects and challenging issues of communication networks and multimedia technologies, and the contents are built on analytical modelling, experimental and simulation studies. The contributions of these papers are outlined below. With the development of wireless access and multimedia compression technologies, much attention has been devoted to wireless video communications. Wan, Xiong and Yang propose an integrated routing metric to evaluate path quality taking the hop count, congestion bottleneck and other parameters of a path into account. They design the traffic assignment and traffic adjustment modules to make the routing scheme flexible to the changing environments, and present an enhanced link layer scheduling algorithm. Simulation results show that compared to commonly used schemes, the proposed network layer scheme always provides better performance with various traffic modes; combined with link layer scheduling algorithm, the performance could be further improved. High speed and quality multimedia and data transmission requirements exist widely in wireless networks. Wang et al. investigate the performance of opportunistic scheduling in wireless multimedia and data networks based on popular stochastic network calculus (SNC). The authors firstly bound the traffic arrival process using the exponentially bounded burstiness traffic model of SNC and establish a stochastic arrival curve, and then propose a new wireless opportunistic scheduling, i.e., modified proportional fairness (MPF) scheduling algorithm, which can provide better fairness for input traffic to guarantee QoS performance, and obtain a stochastic service curve. The numerical results show that the proposed stochastic model and MPF scheduling algorithm can provide better QoS performance. Multimed Tools Appl (2015) 74:1–3 DOI 10.1007/s11042-013-1647-x

다중 간섭 환경에서 Impulse Radio UWB 시스템의 전송품질 향상에 관한 연구

In this paper, We applied CCI canceller to remove multiple access interference in co-channel environment and improved performance of Impulse Radio UWB system. Also, we have evaluated the performance of UWB system with Truncated Type-II Hybrid ARQ scheme for achieving high quality data transmission.

Adaptive real time wireless data transmission using superposition coding with feedback of channel state information

High quality data transmission services are an important issue for broadband wireless access (BWA) systems. This paper deals with the design issues of a real-time wireless data transmission which provides unequal error protection (UEP) over an additive white Gaussian noise (AWGN) channel. Traditionally, transmission is made from a one bit stream at one level of power (for example, pulse amplitude modulation (PAM)) but using different techniques to exploit the available bandwidth. Using superposition coding, the real time data bit stream can be divided into two bit streams. The first bit stream represents the region of high priority (HP) while the second represents low priority (LP) region. These two bit streams are modulated separately, and superimposed together with two different levels of power to achieve the UEP at the receiver side. Feedback of the channel state information (CSI) is used by adaptive channel in the physical layer such that the current available bandwidth is used efficiently. In this proposed scheme, the same design metrics, namely time, bandwidth and power are used to increase the transmission efficiency. The performance of the proposed scheme is compared with the traditional, 2-PAM and 4-PAM schemes. Unlike the traditional schemes, the results show that our scheme provides a higher data rate at an acceptable bit error rate (BER) when the channel is in good condition. When channel quality is degraded, a reduced data rate is applied in contrast with the traditional schemes. As compared with the traditional 4-PAM scheme, the proposed scheme gives a good error performance for the HP bit stream with 0.2 dB gain increase at BER of 10-5, and exhibited a 4 dB gain when the channel condition is bad. Key words: Superposition coding, real time transmission, UEP, CSI, AWGN.

System Design of High-Definition Media Transceiver based on Power Line Communication and Its Performance Analysis

Due to a development of a modem technology as Power Line Communication(PLC) over 200 Mbps, the high-speed multi-media data trasmission could be currently possible. The strength of the PLC has no more additional wiring work. PLC has also possible to high quality data transmission with currently electrical cable. It has a various strong point campare with existing wire and wireless communication technologies. In This paper we develop a high quality media transmitter-receiver based on merging the HomePlug AV, which is 200 Mbps class PLC technology and HDMI Interface technology. The video function was used for the VEDEO TEST GENERATOR in order to a property valuation. Smart Live 6 software were used for the assessment of audio property. As the result of measurement of the HD class images by capturing from the receiver of the PLC, the quality of images couldn't be confirm any deterioration, which has compared with original reflections. In case of audio part as the result of confirmation of the Phase, Magnitude, it has been confirmed that over 90% of nomal transmition and receiving of acoustic signal. It can be possible to have HD class Media service through the PLC.

Throughput Maximization Transmission Control Scheme for MIMO Systems

Recently, multiple-input multiple-output (MIMO) systems that realize high bit rate data transmission with multiple antennas at both transmitter and receiver have drawn much attention for their high spectral efficiency. In MIMO systems, space division multiplexing (SDM) has been researched widely. In SDM, the input data symbols are transmitted from multiple transmit antennas at the transmitter, and the output data symbols are extracted by the signal processing at the receiver. In recent wireless communications, the environments that the number of transmit antennas is larger than that of receive antennas often exist. Under such environments, the MIMO system that transmits independent data streams from each transmit antenna simultaneously cannot separate the received signals, and the signal quality deteriorates largely. Therefore, we need the scheme that attains high quality and high throughput data transmission under such environments. In this paper, we propose a throughput maximization transmission control scheme for MIMO systems. The proposed transmission control scheme selects a transmission scheme (a set of transmit antennas, modulation schemes, and coding rates) with maximum throughput based on output signal to interference and noise ratio (SINR) and output signal to noise ratio (SNR). We show that the proposed transmission control scheme attains high throughput by our computer simulation.

Mb/s data transmission over a RF fiber-optic link using a LiNbO 3 microdisk modulator

For the first time, we demonstrate data transmission over a radio frequency (RF) fiber-optic link using a LiNbO 3 microdisk configured to modulate an optical carrier. Initial experimental results demonstrate high-quality data transmission up to 100 Mb/s on a 8.7 GHz RF carrier.

Hybrid ARQ and optimal signal—to—interference ratio assignment for high—quality data transmission in DS—CDMA

AbstractCombined error correction and detection techniques, or hybrid automatic—repeat—request (ARQ) schemes with negative acknowledgment are considered for highly reliable reverse link data transmission in direct sequence code division multiple access (DS—CDMA) personal communication systems. The proposed selective repeat hybrid ARQ scheme employs an inner convolutional code for error correction and an outer shortened BCH code for error detection. Each negative acknowledgment message contains all packet sequence numbers that have been detected in error, and it is both error—correction and error—detection encoded. Accepted packet error rate and throughput are derived as a function of the error correction encoded frame error rate. An optimum signal—to—interference ratio (SIR) assignment maximizing the system's capacity is also found. A comprehensive simulation is conducted to evaluate performance of the data transmission system. Analysis and simulations show that by applying the proposed type I hybrid ARQ scheme with properly selected system parameters, virtually error free and highly efficient data transmission in CDMA personal communication systems is possible.

A comparative study of doubly connected directed topologies for LANs and MANs

This article provides an overview of doubly linked networks. We first classify the doubly linked network on the basis of the number of tuples used to represent each node address in the network. Then, each subclass of network is further partitioned into loop or nonloop categories. Various routing algorithms are studied and grouped into static or adaptive routing type, based on the number of paths between nodes used in the point-to-point message transmission. The useful protocols of the token ring and the register insertion ring and their relative advantages are also described. Some issues, such as multiple destinations routing, graceful degradation on cluster faults, and network behavior under unbalanced traffic conditions, in a doubly linked network are still open. There seems to be a need for new protocols when optical fiber is used as the medium for message transmission, which necessitates high-quality and large bandwidth data transmission. © 1996 John Wiley & Sons, Inc.

Complexity reduction and performance improvement of a decision feedback equalizer for 16QAM in land mobile communications

This paper proposes a complexity-reduced decision feedback equalizer (DFE) for 16-ary quadrature amplitude modulation (16QAM) using tap gain interpolation, bi-directional equalizing (BDE) and space diversity combining (SDC) to achieve high spectral efficiency and high quality data transmission over frequency-selective fading channels in land mobile communications. To reduce the amount of computation required for BDE and SDC, we propose a tap gain interpolation scheme and pre-decision schemes for both processes. Computer simulation of a (16QAM/TDMA system) confirms that the proposed scheme improves frequency-selective fading compensation performance by 6 dB or more while using only 27% of the computation of conventional single branch DFE receivers.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Transformation of mechanized locomotives into semi-autonomous machines

Computerized communications (radio) command, control, and monitoring (C/sup 4/M) technology has been developed to replace mechanical controllers on 35 ton locomotives (loci). The C/sup 4/M technology uses medium frequency (MF) underground radio technology developed in prior US Bureau of Mines research to achieve high-quality voice and data transmission in the mining complex. Robust electrical conductors such as rail, air/hydro pipe, and cable provide a signal transmission medium with an attenuation rate of 4 dB/304 m (1000 ft). The signal-to-noise ratio (SNR) exceeds 30 dB in the transmission system. A surface supervisory computer communicates with the C/sup 4/M controller via MF radio to create a semiautonomous locomotive. Diagnostic algorithms monitor locomotive sensors and locate failures in the propulsion system. The C/sup 4/M controller has reduced propulsion system diagnostic time from an average of 40 to less than 10 min. The increased machine availability time contributes 17000 tons of additional ore to the trains' haul age potential each year. >

Operating aspects of new LRE/DSI DCMEs

AbstractDigital circuit multiplication equipment (DCME) that uses a combination of talk‐spurt interpolation and low‐rate encoding (32 kb/s ADPCM rather than the traditional 64 kb/s PCM) is about to be introduced in operating satellite systems. These DCMEs possess a number of important features that have been introduced to achieve a suitable balance between high channel multiplication ratios and high quality voice and data transmission. The methods used to accomplish this are generation of overload channels to virtually eliminate talk‐spurt clipping, establishing a limit on the fraction of channels that undergo bit reduction by use of dynamic load control, automatic routeing of trunks carrying in‐band data signals to non‐interpolated bearer channels, use of a bit‐bank approach to provide five‐bits/sample ADPCM coding for in‐band data channels and rotation of the server channels among the talk‐spurts to spread the degradation caused by bit reduction uniformly across all talk‐spurts. This paper analyses the performance of the DCME embodying the above features, and presents results in terms of the input‐to‐output channel multiplication ratio (CMR) as a function of the number of bearer channels (over a range from 4 to 61 bearer channels) and the number of input channels carrying in‐band data. Extending the operation range down to as few as four bearer channels permits evaluation of the effectiveness of multiclique operation. In addition, the influence on CMR of (a) non‐bit‐bank operation, that would be possible if an ADPCM codec capable of supporting in‐band data carriers at four‐bits/sample were used, and (b) a short‐hangover‐time speech detector are examined. Use of hangover times less than 30 ms are shown to achieve a CMR of as great as 3.3: 1.