LDPC CODING:
The constraint of minimizing the dependence between the system’s receiving branches, thus reducing the relevant transmitter and receiver complexities.The concept of Multiple-Input Multiple-Output (MIMO) still represents a prevailing research direction in wireless communications due to its ever increasing capability to offer higher rate, more efficient communications, as measured by spectral utilization, and under low transmitting or receiving power.
Fig:LDPC
Precoding is a generalization of beamforming to support multi-stream (or multi-layer) transmission in multi-antenna wireless communications. In conventional single-stream beamforming, the same signal is emitted from each of the transmit antennas with appropriate weighting (phase and gain) such that the signal power is maximized at the receiver output. When the receiver has multiple antennas, single-stream beam forming cannot simultaneously maximize the signal level at all of the receive antennas.
globally optimal linear precoding techniques were presented for finite alphabet inputs, capable of achieving mutual information rates much higher than the previously presented MWF techniques, by introducing input symbol correlation through a unitary input transformation matrix in conjunction with channel weight adjustment (power allocation). These mutual information maximizing globally optimal pre coders are more appropriate for LDPC codes which are very popular currently, than e.g., Maximal Diversity Precoders (MDP).LDPC codes is addressed under the constraint of minimizing the dependence between the system’s receiving branches, thus reducing the relevant transmitter and receiver complexities.
FOR MORE DETAILS:
The constraint of minimizing the dependence between the system’s receiving branches, thus reducing the relevant transmitter and receiver complexities.The concept of Multiple-Input Multiple-Output (MIMO) still represents a prevailing research direction in wireless communications due to its ever increasing capability to offer higher rate, more efficient communications, as measured by spectral utilization, and under low transmitting or receiving power.
Fig:LDPC
Precoding is a generalization of beamforming to support multi-stream (or multi-layer) transmission in multi-antenna wireless communications. In conventional single-stream beamforming, the same signal is emitted from each of the transmit antennas with appropriate weighting (phase and gain) such that the signal power is maximized at the receiver output. When the receiver has multiple antennas, single-stream beam forming cannot simultaneously maximize the signal level at all of the receive antennas.
globally optimal linear precoding techniques were presented for finite alphabet inputs, capable of achieving mutual information rates much higher than the previously presented MWF techniques, by introducing input symbol correlation through a unitary input transformation matrix in conjunction with channel weight adjustment (power allocation). These mutual information maximizing globally optimal pre coders are more appropriate for LDPC codes which are very popular currently, than e.g., Maximal Diversity Precoders (MDP).LDPC codes is addressed under the constraint of minimizing the dependence between the system’s receiving branches, thus reducing the relevant transmitter and receiver complexities.
FOR MORE DETAILS:
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