Hybrid Spread Spectrum Techniques for Cell Phone Essay -- Technology

In addition to the oftenness hopped and direct sequence, spread spectrum multiple main course technique, there are certain other hybrid combinations that provide the advantage in the area of cellular mobile communication system. The available wideband spectrum is dual-lane in to a number of subspectras with smaller bandwidth. frequency Hopped Multiple admission charge Technique (FHMAT) consists of a direct sequence modulated signal whose center frequency is made to hop periodically in a pseudorandom fashion. In this paper we provide a Hybrid Spread Spectrum Techniques using Time Division encipher Division Multiple Access (TDCDMA) system in which different spreading codes are assigned to different cell within each cell, only unitary user per cell is allotted a particular time slot. Time Division Frequency Hopping Multiple Access (TDFHMA) Technique has an advantage in unvoiced multipath or when severe co-channel interference occurs. The subscriber can hop to new frequency at the s ubscriber can hope to new frequency at the start of a new time division multiple access frame. These different areas covered by the antenna beam may be served by the same frequency or difference frequency.Keywords Frequency Hopped Multiple Access, Time Division Code Division Multiple Access, Time Division Frequency Hopping, distance Division Multiple Access1 IntroductionSpread spectrum techniques spread information over a very large bandwidth specifically, a bandwidth that is much larger than the inverse of the data rate. In this paper we are discussing various ways of providing multiple access by spreading the spectrum. We start out with the conceptually simplest approach, Frequency Hopping (FH). We then proceed to the most popular form of spread spectrum, Direct Sequence-Code D... ... Hybrid Wireless Networks Using Autonomic Computing Principles IEEE, CNSR, 20054 C. Lo, E. Masry, and L. B. Milstein, Design and Analysis of a Fast Frequency-Hopped DBPSK Communicati on System, Part I, IEEE Trans. Commun., Vol. COM-41, pp. 1552-1564, 19935 Masato Mizoguchi and Kazuhiko Seki , In-Chip Fast Frequency Hopped and Direct Sequence CDMA Systems for Indoor Wireless Communications,IEEE Trans. Commun, pp.1508-1512, 19966 Andreas F. Molsch, Spread Spectrum Systems, publisher by Wiley India Edition, pp. 469-471,2005. 7 Theodore S. Rappaport, Multiple Access Technique for Wireless communications, Second Edition pp. 451- 463, 1996. 8 Q. Chen, Q. Wang and V. K. Bhargava, Error Performance of Coded SFHiDPSK in Tone Interference and AWGN, IEEE Confrence Milcom, pp. 63-67, 1992.