Satellite communications - system and its design technology [Book Review]

When I was a child in 1960 or so my parents gave me a mechanical toy made of painted sheet steel and plastic details. It was a rocket base, which supported one fantasy spacecraft hanging on a long arm. Near one corner was a small cryptic label “Made in Japan.” After tediously winding the heavy built-in spring with my weak fingers, I was able to make the capsule go around and around whereby our neighbor’s cat got crazy and climbed up the next pine. If I could not hold the thing steady while winding, the key snapped back on my fingers with considerable force and caused a loud cry across the entire universe, or at least up to the living room, and the neighbor’s cat climbed up the pine. Unfortunately, this gadget was later destroyed by the two small outer space aliens, who turned out to be my younger twin brothers. So, that was what we knew about Japanese aerospace engineering forty years ago. Still, they were pursuing more advanced topics then. Now, Japan is one of the few nations capable to run an independent civilian space research program. The start was partly based on imported US technology, but gradually the local scientists and engineers got more experience, which later led to the first Japanese launches of both communication and broadcasting satellites in 1977 and 1978. After that, progress has been fast and today Japan has a set of top facilities for satellite research. The book under review, Satellite Communications Sysrem and Ifs Design Technology is, on one hand, a documentation of the recent technical achievements but, on the other hand, an educational text book of related topics. It was edited by Takashi Iida, from the Communications Research Laboratories in Japan, initially in Japanese to celebrate the first 100 years of radio communication in his country. Recently, 10s Press saw the value of this work and supported a translation and editing process which also enables us here, in the English speaking part of the world, to familiarize ourselves with the Japanese contributions to modem satellite communications. Satellite Communications is a compiled document. Besides Dr. Iida, thirteen distinguished scientists from Japan have been directly involved in the production of the hook. The co-authors include two university professors, two high-level directors of YRF’ (Yokosuka Research Park) communication companies, one senior scientist from the NASDA (National Space Development Agency, approximately Japan’s NASA) and several specialists from the CRL, which is an acronym for the Communications Research Laboratory working directly under the Japanese Ministry of Posts and Telecommunications. The authors aimed at making a book which describes the fundamental technologies required to get a comprehensive understanding of satellite communication systems. Their target audience comprises undergraduate and graduate students those young people who should continue the development process in the 21“ century. Let’s first have a brief look at the statistics of this handy book. We have 424 pages in total, divided into ten separate main chapters. Some chapters have one or two very short appendices, which are used to discuss in detail selected small but important issues. The table of contents gives a three-level structure for each chapter, which seems to be a very good balance between reader convenience and logical indexing. There are about 280 illustrations, both line art and photographs, and 430 mathematical equations. The readability factor looks pretty good. In the end, we have an alphabetical index of roughly 700 items and a list of references, which contains 200 international publications. Some 40% of these are of Japanese origin and more than half come from the 1990s. The authors wanted to create a book for students, because each chapter has a number of exercises the whole volume about 50 and selected answers are given as well. The overall impression is friendly; the book is not too “massive” but doesn’t look like a leaflet, either. The book has four main topical areas. It discusses radio engineering for satellite systems, satellites as space vehicles, communication aspects including digital modulation and coding, and finally, gives a brief look at future challenges related to packet networks. Chapters 3,4 and 6 cover topics on radio wave propagation, antennas, satellite transmitters and receivers, and earth station electronics. For some reason, Chapter 2 which shows the various orbits and attitude stabilization problems, is not adjacent to Chapter 5 , where satellite tracking and attitude control systems are illustrated. Maybe a different order of presentation would be of some benefit. The remaining chapters are devoted to multiple access (the well-known acronyms FDMA, TDMA, and CDMA for frequency, time and code division multiple access have each their own sub-section), to phase and frequency modulation and