What are the components of the communication base station? What's the connection between them?
Because the signal is transmitted to the base station may be relatively weak, and there is a certain signal interference, so the pre selector.Modular filtering and amplification, double frequency conversion, amplification and frequency discrimination. The input high frequency signal is amplified and sent into the first frequency converter, and the frequency of the first machine oscillation signal provided by the frequency converter is 766.9125-791.8875MHz, and the first intermediate frequency signal of the 123.1MHz is generated after the lower frequency conversion. The first intermediate frequency signal is amplified, filtered and mixed to generate a second intermediate frequency signal (21.3875MHz), which is amplified and filtered to send to an intermediate frequency integrated block. If the integrated block (including second intermediate frequency signal amplifier, limiter and discriminator) audio output signal and the received signal strength indicator (RSSI) sent to the audio / audio signal in the control panel, control panel, a diversity switch constant comparison between odd and even signals, strong signal and select which, by audio circuit is transmitted to the mobile control center.
The use of the antenna base station for transmitting antenna and receiving antenna, and omnidirectional and directional points, generally have the following three types of configurations: omnidirectional, omnidirectional mode; hair, hair style omni directional, directional orientation. Literally we can understand each kind of different types of signal sending omnidirectional is mainly responsible for the full range of the received signal is received; omnidirectional natural orientation; directional meaning is only at a fixed angle for sending and receiving. In general, the base station channel number less (such as suburban) is often used to send, receive omnidirectional omnidirectional mode, and the base station channel number, by omni directional manner, and establish base is also more intensive than in the suburbs.
The base transceiver station in control of the base station controller, complete the conversion between the base station and the control of the wireless channel, between the transceiver and the mobile platform mobile phone communication signals through wireless transmission and air control function related. The transceiver can decode and transmit wireless signals for each user.
Seeing the high antenna on the roof is a part of the base station transceiver. A complete base station transceiver includes a wireless transmit / receive device, an antenna, and signal processing sections that are unique to all wireless interfaces. Base transceiver station can be regarded as a wireless modem, which is responsible for the reception and transmission of mobile signals. The general situation in a region, a plurality of sub base transceiver station and each composed of a cellular network, transmitting signals between each other through the control and transceiver station transceiver station and receiving to mobile communication signal transmission, within the scope of this area is what we often say that the network coverage. If there is no transceiver, it is impossible to complete the transmission and reception of mobile phone signals. The area where the base station transceiver cannot cover is the blind area of the mobile phone signal. Therefore, the range of transmitting and receiving signals of the base station transceiver station is directly related to the quality of the network signal and whether the mobile phone can be used normally in the area.
