Current and future applications impose high demands on software-defined radio (SDR) platforms in terms of latency, reliability, and flexibility. This paper presents a heterogeneous SDR MPSoC with a hexagonal network-on-chip to address these issues. It features four data processing modules and a baseband processing engine for iterative multiple-input multiple-output (MIMO) receiving. Integrated memory controllers enable dynamic data flow mapping and application isolation. In a 4 x 4 MIMO application scenario, the MPSoC achieves a throughput of 232 Mbit/s with a latency of 20 μs while consuming 414 mW. It outperforms state-of-The-Art platforms in terms of throughput by a factor of 4.