A vertical organic light emitting transistor assembly and a horizontal organic light emitting transistor assembly are provided. The receiving unit receives digital broadcasting. The present invention also provides a heat-shrinkable film having a three-layer structure containing front and back layers and a core layer, wherein the above-mentioned copolymer b1 andor copolymer b2 forms the core layer. Local echoes are effectively reduced and local receiver training is improved without affecting eventual data transmission performance.