[0003] 1. Due to the limitations of geographical location (ocean, desert and hills, etc.),
environmental protection and rights protection (commercial and residential quarters and cultural relics protection areas, etc.), and
station construction conditions (
electric power, iron towers, transmission, funds, etc.), it is impossible to solve the
communication problem through the new station Coverage hole problem
[0004] 2. Since the wireless
terminal equipment is limited by
small antenna size,
battery capacity, transmission power, etc., the terminal (for land
mobile communication network can be
mobile phone or
wireless network card, etc., for
satellite communication can be a
transponder) to the main station (for land
mobile communication network, it can be a
transponder) The
mobile communication network is called a
base station, and it can be a
ground station for
satellite communication) The transmission link is a weak link, and its performance is far lower than the link performance from the main station to the terminal, that is, there is an imbalance between the uplink and downlink. The weak link determines the coverage and
communication quality of the network, and becomes a
bottleneck for realizing a high-performance network system
[0005] 3. At present, the number of various main stations and
terminal equipment is increasing day by day, wireless communication frequency resources are tight, the frequency of spectrum used is getting higher and higher, the propagation characteristics are getting worse and worse, the distance between main stations is getting closer and closer,
intranet and competition network The frequency
pollution caused by interference and other interference is becoming more and more serious, which reduces the
signal-to-
noise ratio of the
signal received by the main station and seriously affects the communication coverage,
communication quality and
system capacity.
[0009] 1. There is no
receiver for all existing equipment, and it is impossible to have a
radio frequency bandpass filter with extremely steep receiving filter characteristics, extremely small
insertion loss, small fluctuations in the wide-pass
frequency band, and a rectangular coefficient close to 1 with traditional technology. Effectively filter out the interference outside the
passband (
stopband), and reduce the
intermodulation interference caused by these interferences entering the
receiver, which improves the system
noise floor
[0010] 2. All the above-mentioned devices amplify the received
signal and noise at the same time, and the noise is accumulated on the receiving link instead of weakened. The result is that the quality of the received signal is getting worse and worse
[0011] 3. The low-noise amplifiers of the RF front-end of the receiver of all the above-mentioned devices work at
room temperature. Due to the thermal noise generated by the electronic
Brownian motion, the
amplifier amplifies the noise generated by itself, which raises the bottom noise of the system and deteriorates the signal-to-noise ratio
Seriously affect communication coverage and quality and capacity
[0012] 4. Where the communication coverage and quality are not good, it is often due to network planning, unreasonable
master station layout (such as
high density of land mobile communication base stations, frequent
cell switching or unreasonable coverage and frequency planning, etc.),
pilot pollution and various In areas with severe interference, increasing the
master station, frequency configuration and equipment configuration in these areas is often a large amount of investment, but it will cause further interference and frequency
pollution, increase system and maintenance costs, and further reduce
resource utilization such as frequency and equipment.
In fact, most sources of interference and faults in the network come from
tower amplifiers, repeaters and indoor distribution systems, which seriously pollute the network environment
[0013] 5. Since factors such as available resources, internal and external interference, and changes in business demand are uncontrollable, using the above-mentioned methods and technologies to solve problems will always be a passive fix.
[0014] To sum up, the use of existing traditional technical means and equipment cannot fundamentally solve the problems of: removing external interference and
intermodulation interference; reducing the bottom noise of the system itself; effectively improving the
gain and sensitivity of useful signals