Upper Bounds on the Mismatched Reliability Function and Capacity Using a Genie Receiver

We develop a novel framework for proving converse theorems channel coding, which is based on the analysis technique of multicast transmission with an additional auxiliary receiver, serves as genie to original receiver. The provides receiver certain narrowed list codewords choose from that includes transmitted one. This used derive upper bounds mismatch capacity discrete memoryless channels well reliability function mismatched decoding metric. Unlike previous works, our bounding exploits also inherent symmetric requirement codewords, leading these new bounds. Since computations most known are rather complicated, we further present method obtain relaxed easier compute. As example, analyze obtained in binary-input case. conclude by presenting simpler function, and provide sufficient conditions their tightness ranges rates.