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Essay On Summing Circuit

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a simple phase lock summing circuit which is very easy to implement.EGC can engage in the reception of diversity with coherent modulation. As in EGC the diversity branches are combined with equal gain but they have conjugate phase. Maximum ratio combining technique requires summing circuits, weighting and co-phasing. Each of the signals from different branches are weighted and co-phased with a gain factor which is proportional to the SNR before summing or combining. The applied weighting to the diversity branches has to be adjusted according the SNR. Techniques used in MIMO system In wireless communication system MIMO is used to provide better performance as compared with others conventional systems. The multiple data stream is provided in …show more content…

V-BLAST algorithm at the receiver is used to mitigate the interference between different streams and try to generate the original data stream at the receiver. V-BLAST used optimal combining and interference cancellation technique. The signal which is having the best SNR is retrieved at the receiver. In the figure shown below which illustrates the good performance achieved at the receiver. V-BLAST technique is referred as non-linear technique as it generates the best signals for cancellation. Transmitter Processing Only In this technique of MIMO system, the signals processing occurs at the transmitter only as the signal processing is restricted at the transmitter therefore it is more beneficial for downlink scenario, because no signals is required at the mobile station. In case of downlink system there is N number of antennas at the receiver with having N number of data stream and each of it is multiplexed and output. There were three techniques used by the MIMO system with antenna processing at the transmitter and having a simple receive structure which is the transient zero forcing scheme, Filter bank method and transmit MMSE. All the interference has been cut by the transmit zero forcing technique whereas the filter bank method is used to minimise the signal to interference ratio in all sub-channels. Processing at Both the Receiver and

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