The Zero-Error Capacity Region of the 2-User Synchronous BAC is Strictly Sinaller Than its Shaxiiioii Capacity Region
Riidiger Urbanke, Quinn Lit · 1978
New u pper and lower bounds on the zero-error capacity region of the synchronous 2-user binary adder channel are given. The lower bound is in the form of a new uniquely decodable c ode with sum rate higher than any previously reported s uch code. To derive the upper bound, we combine Van Tilborg's bound with Harper's isoperimetric inequality and a general information theoretic inequality. From this bound we conclude that t he zero-error capacity re- gion of the synchronous 2-user binary adder channel is strictly smaller than its associated Shannon capac- ity region.