Manchester Encoding Research Articles

Performance Analysis of Enhanced-MPC in Incoherent Synchronous Optical CDMA

A novel spreading code set based on the prime code (PC) families, referred to ¿Enhanced-Modified PC,¿ is proposed for incoherent synchronous optical code-division multiple-access (OCDMA) network. The new code set is employed to Pulse-Position Modulation-OCDMA scheme and the system throughput is also analyzed; the overall system performance in terms of bit-error rate is then evaluated and compared with existing PC families in three types of receiver architectures: 1) basic functionalities; 2) with an multiple-user interference (MUI) cancelation; and 3) with the MUI canceler coupled with Manchester encoding. The results indicate that the proposed code set is promising to enhance the network capacity.

What is Manchester encoding?

When developing an embedded system that requires basic serial network communications, the list of design options are plentiful. But when all of the off-the-shelf alternatives fail to meet your requirements, it's worth remembering that traditional and well-tested protocols, such as Manchester encoding, offer some unique alternatives to the current commercial methods of wired and wireless control-data transmission.

Manchester encoded bandpass sigma–delta modulation for RF class D amplifiers

An analysis of a continuous-time bandpass sigma–delta modulator in a configuration with an upconverter is given for a RF class D amplifier application. The upconverter multiplies the modulator pulse train with a synchronised clock signal and maps each modulator bit to an integer multiple k of a (+1, −1) or (−1, +1) pattern depending on the sign of the modulator bit. The upconversion is equivalent to an extension of Manchester encoding, which is usually defined for k=1. The analysis focuses on evaluating the impact of upconversion on the modulator coding efficiency and the average pulse period. A design equation is derived, which shows that coding efficiency is dependent only on the upconversion frequency ratio, while the average pulse period depends only on k. The equations provide a designer with a way of evaluating the trade-offs in the amplifier system and show that encoding with k=1 is the most efficient configuration for maximising coding efficiency and minimising switching power loss.

Wireless Baseband Transmission Experiments

A baseband transmission scheme for wireless communications has been proposed and examined using a pair of discone antennas for transmission and reception. The wireless baseband transmission scheme radiates a baseband signal stream, such as non-return-to-zero (NRZ), retum-to-zero (RZ), or Manchester encoded signals, directly from an antenna. Namely, a carrier in terms of a sinusoidal radio wave or light wave is not used in the transmission. In experiments, baseband pulses generated with a data generator were radiated directly from the discone antenna, and received waveforms were observed with a digital storage oscilloscope. The experiments showed that wireless baseband transmission is realisable when using antennas with a flat amplitude spectrum and a linear phase characteristic, such as discone antennas, over a given band. Manchester encoding is promising for this wireless baseband transmission.

Manchester encoding: opposing definitions resolved

Manchester encoding is widely used to provide clock and data information simultaneously via a single connection. There are two opposing-and incompatible-definitions of Manchester encoding where the rising edge in the centre of the data bit indicates either a logic “1” or alternatively a logic “0”. This paper resolves the differences and identifies the originator of the method.

Implementation of Encoding and Decoding of Digital Signal

In this paper, encoding and decoding of digital signal has been described. Simple practical circuits for the implementation of Manchester and biphase encoder and decoder are given. Detailed description of these circuits, along with the timing diagrams are presented.

Manchester encoder circuit for local area networks

All synchronous serial data transmission systems have to be able to divide the incoming data stream into individual bits at the receiving end of the data link. As it is generally impossible to provide a separate clock channel from the transmitter to the receiver, synchronous systems invariably encode the transmitted data in such a way that the clock signal can be recovered from the received data. A popular method of encoding a data signal and clock signal is called phase encoding, or Manchester encoding. The transmitted signal is forced to make a transition at the centre of each data cell. A logic ‘1’ is transmitted by a ‘0-to-1’ transition and a ‘0’ is transmitted as a ‘1-to-0’ transmission. Until recently Manchester encoders and decoders had to be constructed out of a handful of TTL logic. The widespread application of synchronous serial transmission systems (in particular the growth of LANs based on Ethernet) has encouraged semiconductor manufacturers to produce single-chip Manchester encoder/ decoders. This application note from AMD looks at the design of a Manchester encoder based not on a custom chip but on AMD's PALC22V10 programmable array logic element. Modem programmable logic elements are able to synthesize circuits that would have required ten or more SSI and MSI packages and have taken up a large area on a PCB. The PALC22V10 contains both the combinational logic and the sequential logic elements necessary to design functional logic blocks such as Manchester encoders. A.C.