Question: What is the purpose of transmitting at least one symbol with demodulation reference signal on each layer on each frequency hop in which the PUSCH is transmitted?
Option 1: To aid receiver phase tracking
Option 2: To enable accurate channel estimation and demodulation
Option 3: To increase the data transmission rate
Option 4: To reduce the interference between different layers
Explanation: The transmission of at least one symbol with demodulation reference signal on each layer on each frequency hop in which the PUSCH is transmitted enables accurate channel estimation and demodulation, allowing the receiver to properly decode the received signal. This is a critical aspect of physical-layer processing for physical uplink shared channels.