Synchronous Hybrid Automatic Repeat Request (HARQ) is a technique used in wireless communication systems to improve the reliability of data transmission by retransmitting the data if errors are detected. In synchronous HARQ, retransmissions are sent at specific timeslots after the original transmission, which can cause delay in data transmission.
In 5G, asynchronous HARQ is used instead of synchronous HARQ because it offers several advantages over synchronous HARQ. Asynchronous HARQ allows for retransmissions to occur as soon as possible after errors are detected, rather than waiting for a specific timeslot. This reduces the delay in data transmission and can improve the overall throughput of the system.
Furthermore, asynchronous HARQ allows for more flexible scheduling of retransmissions, which can improve the efficiency of the system. In synchronous HARQ, retransmissions must be scheduled at specific timeslots, which can be less efficient if the channel conditions change rapidly.
Overall, the use of asynchronous HARQ in 5G allows for more efficient and flexible retransmission of data, which can improve the reliability and throughput of the system.
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