  In wireless OFDM communications systems, pilot tones, due to their publicly
known and deterministic characteristic, suffer significant
jamming/nulling/spoofing risks. Thus, the convectional channel training
protocol using pilot tones could be attacked and paralyzed, which raises the
issue of anti-attack channel training authentication (CTA), i.e., verifying the
claims of identities of pilot tones and channel estimation samples. In this
paper, we consider one-ring scattering scenarios with large-scale uniform
linear arrays (ULA) and develop an independence-checking coding (ICC) theory to
build a secure and stable CTA protocol, namely, ICC-based CTA (ICC-CTA)
protocol. In this protocol, the pilot tones are not only merely randomized and
inserted into subcarriers but also encoded as diversified subcarrier activation
patterns (SAPs) simultaneously. Those encoded SAPs, though camouflaged by
malicious signals, can be identified and decoded into original pilots for
high-accuracy channel impulse response (CIR) estimation. The CTA security is
first characterized by the error probability of identifying legitimate CIR
estimation samples. The CTA instability is formulated as the function of
probability of stably estimating CIR against all available diversified SAPs. A
realistic tradeoff between the CTA security and instability under the
discretely distributed AoA is identified and an optimally stable tradeoff
problem is formulated, with the objective of optimizing the code rate to
maximize security while maintaining maximum stability for ever. Solving this,
we derive the closed-form expression of optimal code rate. Numerical results
finally validate the resilience of proposed ICC-CTA protocol.
