How and What Spatial Diversity Antenna Systems in GSM The spatial diversity antenna system is constructed by physically separating two receiving base station antennas. Here I write on spatial diversity antenna system criteria, configuration. SPATIAL DIVERSITY ANTENNA SYSTEMS Once they are separated far enough, both antennas receive independent fading signals. As a result, the signals … Read more
Diversity Reception: Multiple Antennas at Base Station Each Antenna is Affected by Multipath Differently Due to Their Different Location Allows Selection of the Signal Least Affected by Multipath Fading If Diversity Antennas are Good, Why Not Use Base Stations as a Diversity Network? – Soft Handoff The concept of diversity reception has been well known … Read more
Time diversity is a technique common to most digital transmission systems. The Rake Receiver is used to find and demodulate multipath signals that are time delayed from the main signal. Rake Receiver to Find and Demodulate Multipath Signals. Data is Interleaved : Spreads Adjacent Data in time to Improve Error Correction Efficiency Convolutional Encoding : … Read more
Spatial Multiplexing In a multipath environment, the data rate increase due to MIMO is equal to the number of MIMO antennas. Rather than to transmit the same bit of more than two antennas, the Spatial Multiplexing method sends a data bit from the first antenna, and another bit of the second antenna at the same … Read more
Make use of a number of receive antennas that are well separated (coherence distance) to generate independent receptions of the transmitted signal. Selection diversity: choose received signal with largest received power, S/N, etc. Switched diversity: choose alternate antenna if signal falls below a certain threshold. Linear combining: linearly combine a weighted replica of all received … Read more
We know that we normally have several independent paths from TX to Rx of different lengths, these are affected and delayed differently, Signals that start out together at the transmitter will be separated in time when they reach the receiver Diversity doesn’t work with Line of Sight, This is exploiting Multipath rather than fighting it … Read more
Here I write down which point to tack care during antenna installation which including Wind load, Work Temperature and Humidity and Camouflaged Antenna Scheme for Sites Wind Load The antennas are usually installed on high buildings or towers. In the littoral areas, the wind is strong with high speed, so the antennas are required to … Read more
Here I write down some passive characteristics definition for antenna which include Port Isolation, Power capacity, Input Port of Antenna, Passive Intermodulation (PIM) and Dimensions and Weight of Antenna. For multi-port antennas, such as dual polarization antenna and dual band dual polarization antenna, the isolation must exceed 30 dB when the Rx port is the … Read more
Any Antenna may be Omni antennas or Directional antenna. Omni antennas provide approximately the same amount of profit throughout the entire 360-degree horizontal pattern. Directional antenna, sometimes referred to as sector antennas have the maximum winnings in one direction from the backside, usually 15-25 DB below the maximum benefit. Antenna gain is a function of … Read more