Pilot allocation trade-off for low latency and high reliability transmission
5G is expected to support a wide variety of new services which will potentially have quite strict requirements on the wireless communication link. Currently, the standard indicator of a service requirement is its Latency/Reliability tolerance. The 5G usecases demand ultra low latency and ultra high reliability. Generally speaking, those two requirements are contradictive. Latency and reliability budgets are a function of all the parameters in the communication layers. This work investigates the latency/reliability aspect at the PHY layer. One of the most influential parameters which control latency and reliability is the pilot design. For a constrained bandwidth, increasing the pilot density will enhance reliability, but will increase latency due to the increased pilot overhead, and vice versa. Hence, there exists a trade-off pilot allocation which balances the contradicitve requirements of latency and reliability. This work proposes a practical method for the transmitter to tune the pilot spacings based on the optimal solutions of latency/reliability.