IMPROVED REVERSE PATH AUTOGAIN CONTROL

摘要

In a wireless microcell distribution system, a method is provided for level adjustment of signals from the microcells in which a shortened gain tone is used to minimize interference with a phone call. The gain tones for the primary and diversity receive paths from a microcell, rather than being generated simultaneously, are brought up independently. In one embodiment, each of the gain tones is limited to 120 milliseconds. Gain tone measurement is likewise done on an independent basis so that rather than both of the gain tones being on simultaneously for the entire measurement period, each of the gain tones only needs to be on for that portion of the measurement period corresponding to the measurement of the gain tone for the primary or diversity receive path. Additionally, the absolute amplitude of the gain tones is reduced to minimize the impact of the automatic gain control on the system. Moreover, in one embodiment, rather than being injected at the primary and diversity circulators coupled to the primary and diversity receiving antennas, the shortened gain tones are injected after the first down-conversion stages so that the power level at which the gain tones are injected can be increased, thus to reduce vulnerability to noise.