Comparison of Channel Estimation Protocols for Coherent AF Relaying Networks in the Presence of Additive Noise and LO Phase Noise

EURASIP Journal on Wireless Communications and Networking

Table 1 Direction of measurement and required number of channel uses to estimate all first-hop and second-hop channel coefficients.

	First-hop channel	Second-hop channel
Protocol A1	Forward direction	Forward direction
Protocol A2	Backward direction	Backward direction
Protocol B1	Forward direction	Backward direction
Protocol B2	Backward direction	Forward direction