Unit VIII multichannel communication systems

Part A

Word List

alleviation	/q"li:vI'eISqn/	облегчение; смягчение
amplifier	/'xmplIfaIq/	усилитель; линза
band	/bxnd/	полоса частот
coherence	/kqu'hIqrqns/	связь; сцепление; связность
comprise	/kqm'praIz/	включать; заключать в себе
conventional	/kqn'venSqnl/	обычный
crosstalk	/'krPs"tLk/	перекрестные помехи
deploy	/dI'plPI/	развертывание; развертывать; приводить в действие
designated	/'dezIgneitId/	определяемый, назначенный
deviation	/"di:vI'eISqn/	отклонение; отступление
domain	/dqu'mein/	домен, зона
implementation	/"implimen'teiS(q)n/	выполнение, осуществление
embodiment	/Im'bPdImqnt/	воплощение; олицетворение; объединение
enhance	/In'hQ:ns/	увеличивать; усиливать
feasible	/'fi:zqbl/	выполнимый; осуществимый; исполнимый
impairment	/Im'peqmqnt/	ухудшение; повреждение
induced	/In'dju:st/	вызванный; вынужденный
multiplex	/'mAltIpleks/	многократный; сложный; составной
orthogonal	/O:'TPgqnl/	прямоугольный; ортогональный

1. Define the following words as parts of speech and give the initial words of the following derivatives.

Conventional, employer, carrying, emitted, systems, amplifier, development, modulated, internationally, converting, increasing, frequencies, transparency, significantly, requirement, useful, particularly.

2. Read the following words in each line and define their roots. Translate the words into Russian:

1. currently, current, currency;

2. optical, optics, optician;

3. plurality, pluralism, plural;

4. interconnected, interconnect, interconnection;

5. modulate, modulation, module;

6. converting, convertible, convertibility, converter, convert;

7. compensation, compensator, compensative, compensate;

8. conventional, conventionalism, conventionality, conventionalize;

9. frequency, frequentative, frequenter, frequent;

10. separate, separation, separatism, separator.

3. Fill in the gaps with words derived from the words in brackets.

1. Wavelength division multiplexed (WDM) communication systems though … (significant) enhancing capacity of communication networks have certain technical limitations.

2. Broadening the spectral band of the optical amplifier … (requirement) new types of amplifiers operating in a wider band than conventional erbium-doped fiber amplifiers (EDFAs).

3. To reduce spacing between WDM channels, new WDM transmitters, multiplexers and demultiplexers should be … (use) with narrower transmission band and tight performance specifications which are not commercially available at this time.

4.The effect of four-wave mixing is … (intensify) as the number of equally spaced channels increases and as the power per channel increases.

5.Nonlinear effects in the optical link, … (particular) four-wave mixing, cause channel crosstalk and lead to significant performance degradation for the overall system.

4. In paragraphs 1 – 4 find the words similar in meaning to the following ones.

One, nowadays, connections, filament, great number, include, embrace, different, turning into, use, development.

5. Read the text and name the problems considered in it.