Software-Defined Radio (SDR) represents a move from dedicated hardware to software implementations of digital communication standards. This approach offers flexibility, shorter time to market, maintainability, and lower costs, but it requires an optimized distribution of SDR tasks in order to meet performance requirements. In this context, we study the problem of scheduling SDR linear task chains of stateless and stateful tasks. We model this problem as a pipelined workflow scheduling problem based on pipelined and replicated parallelism on homogeneous resources. Based on this model, we propose a scheduling algorithm named OTAC for maximizing throughput while also minimizing the number of allocated hardware resources, and we prove its optimality. We evaluate our approach and compare it to other algorithms in a simulation campaign, and with an actual implementation of the DVB-S2 communication standard on the AFF3CT SDR Domain Specific Language. Our results demonstrate how OTAC finds optimal schedules, leading consistently to better results than other algorithms, or equivalent results with much fewer hardware resources.