【資料名稱(chēng)】：跳頻相關(guān)

【資料作者】：廠家

【資料日期】：11月

【資料語(yǔ)言】：中文

【資料格式】：DOC

【資料目錄和簡(jiǎn)介】：

1 Introduction
Frequency hopping means that multiple frequencies are used for the transmis-sion
of speech or data in a single connection. Each burst is transmitted on a
fixed frequency, but the frequency is changed between bursts. A burst can
easily be lost when the mobile happens to be located in a fading dip for that
particular frequency, or if it is subjected to interference. The next burst, if on a
different frequency, has a good chance to come through. The coding and
interleaving scheme in GSM is constructed so that loss of a single burst shall
have minimal influence on the speech quality.
A predefined set of frequencies is used in each cell. The mobile and the base
station change frequency between every burst, i.e. 217 times per second. The
same sequence is used in the uplink and in the downlink.