Pulse Position Modulation Code Research Articles

Various transmission codes for the control of bit error rate in both optical wired and wireless communication channels

Abstract This study clarifies the data error rates optimization for OFC/OWC channels based on different transmission codes. These codes that are namely multi bits/symbol digital pulse interval modulation (DPIM), multi bits/symbol pulse position modulation (PPM), nonreturn to zero inverted (NRZI), 4 bit data symbol/5 bit code (4B5B), and Manchester for upgrading optical wired/wireless communication systems. The optical power through OFC/OWC channels, S/N ratio, the output power at the receiver side are stimulated with high bit transmission rates. The effects of coding complexity on the Q-factor, BER, optical power, and electrical received power are also stimulated using both DPIM and PPM coding.

The enhanced measurement-device-independent quantum key distribution with heralded pair coherent state

With heralded pair coherent states (HPCS), orbital angular momentum (OAM) states and pulse position modulation (PPM) technology, a decoy-state measurement-device-independent quantum key distribution (MDI-QKD) protocol is proposed. OAM states and PPM technology are used to realize the coding of the signal states in the HPCS light source. The use of HPCS light source, OAM coding and PPM coding cannot only reduce the error rate but also improve the key generation rate and communication distance. The new MDI-QKD protocol also employs three-intensity decoy states to avoid the attacks against the light source. By calculating the error rate and key generation rate, the performance of the MDI-QKD protocol is analyzed. Numerical simulation shows that the protocol has very low error rate and very high key generation rate. Moreover, the maximum communication distance can reach 455 km.

串行级联脉冲位置调制码辅助的时隙同步技术

串行级联脉冲位置调制码辅助的时隙同步技术

Ghosts in the data: false detections in VEMCO pulse position modulation acoustic telemetry monitoring equipment

False-positive data (better known as “false detections”) in VEMCO VR2 acoustic telemetry monitoring studies that use pulse position modulation coding can cause biased or erroneous outcomes in data analysis. To understand the occurrence of false detections in acoustic monitoring data sets, the results of a range test experiment using eight acoustic receivers and 12 transmitters were examined. One hundred and fifty one tag ID codes were recorded, 137 of which were identified as likely from false detections, 12 were from test tags, and two were from tagged sharks. False detections accounted for <0.05 % of detections (918) in the experiment. False detection tag ID codes were not randomly distributed amongst the available codes, being more likely to occur at IDs close to tags used in the experiment. Receivers located near the bottom recorded the most false detections and tag ID codes from false detections. Receivers at the same depth did not differ significantly in the mean number of daily false detections. The daily number of false detections recorded by a receiver did not conform to a random pattern, and was not strongly correlated with daily receiver performance. In an era of increasing data sharing and public storage of scientific data, the occurrence of false detections is of significant concern and the results of this study demonstrate that while rare they do occur and can be identified and accounted for in analyses.

Rate‐adaptive indoor infrared wireless communication systems using punctured convolutional codes and adaptive PPM

AbstractIn this paper, we propose rate‐adaptive indoor infrared wireless communication systems using punctured convolutional codes and adaptive pulse‐position modulation (PPM) to achieve high bit rates under various channel conditions with reasonable transmitter power. The proposed system varies the code rate of the rate compatible punctured convolutional (RCPC) codes and the modulation order of PPM adaptively according to the channel condition. When the channel condition is good, low‐order PPM and suitable code rates are selected, while high‐order PPM and suitable code rates are selected when the channel condition is bad. We analyze the performance of the proposed system on hybrid line‐of‐sight (LOS) channels. Our results show that the proposed system can achieve high bit rates by varying the code rate of the RCPC codes and the modulation order of PPM adaptively according to the channel conditions. Moreover, our results show that the proposed system can achieve longer horizontal separation between the transmitter and the receiver than that of conventional systems with repetition codes. © 2001 Scripta Technica, Electron Comm Jpn Pt 1, 84(8): 31–39, 2001

Soliton transmission under pulse position modulation in optical fibres

A new optical pulse train configuration that may propagate with high stability, in normal and anomalous dispersion regimes,in optical fibres is proposed and simulated using pulse position modulation (PPM) coding. The high stability is achieved by simultaneous propagation of two infinite and periodic trains of bright pulses in normal and anomalous dispersion regimes (solitons) in a single-mode optical fibre. This configuration could lead to transmission velocities around 300 Gb/s with good stability under PPM coding. PACS No.: 78.00

Pulse position modulation (PPM) of ultrashort pulse trains in optical fibers

Numerical simulations concerning the dynamical behavior of infinite and periodic pulse trains, for long distance propagation in single mode optical fibers, are presented. A new optical pulse train configuration that may propagate with high stability in the normal and anomalous dispersion regime in optical fibers is proposed and simulated using the pulse position modulation (PPM) coding. High stability is achieved by simultaneous propagation of two infinite and periodic trains of bright pulses in the normal and anomalous dispersion regime (solitons) in a single mode optical fiber. This configuration could lead to transmission velocities around 300 Gb/s with good stability under PPM coding.

Hybrid ppm‐cdma systems utilizing optical orthogonal codes for indoor wireless infrared communication

AbstractAn original hybrid pulse position modulation code division multiple access (PPM‐CDMA) scheme is proposed and studied in the context of the indoor infrared communication network. The use of optical orthogonal codes (OOC) is proposed and original results are presented illustrating the improvement in bit rate achieved by utilizing PPM‐CDMA rather than on/off keying (OOK) CDMA. Results are presented for the maximum number of users that can communicate over the network at a given bit rate and it is shown that there exists an optimum PPM order, at a given number of users, that maximizes the achievable bit rate. Original results are presented for the false‐alarm errors due to the OOC cross correlations, and the optimum system operating parameters that minimize these errors are specified.

New PPM-CDMA hybrid for indoor diffuse infrared channels

An original hybrid pulse position modulation code division multiple access (PPM-CDMA) communication technique that uses optical orthogonal codes (OOCs) is proposed and studied in the context of the indoor infrared channel. At the optimum PPM order and over the range of parameters considered, the hybrid is shown to achieve more than five times the bit rate achievable using conventional on off keying (OOK) CDMA under bandwidth constraints. Original results are presented for the false alarm errors due to the OOC crosscorrelations, and the optimum system operating parameters that minimise these errors are specified.

Pulse position modulation code for the improvement of Doppler shift measurement

Pulse position coding for improving Doppler measurement by pulsed radar with respect to Woodward's expression of Doppler ambiguity is presented. The code of pulse positions is shown to be analytically obtained from the difference between the required ambiguity expression and that of a constant pulse-repetition frequency signal. One feature of the development is the possibility of codes for reducing the spurious peaks that are encountered in the usual ambiguity expression. This is accomplished by an approximation approach using delta functions.