MaxLinear, Inc. is demonstrating its latest advancements in RAN radio technologies at Mobile World Congress (MWC) Barcelona 2026 this week. The company is demonstrating how its Sierra single-chip radio SoC enables OEMs to develop Open RAN Radio Units (O-RUs) addressing key deployment challenges faced by mobile network operators (MNOs). MaxLinear is showcasing Sierra’s embedded Passive Intermodulation (PIM) cancellation technology supports the development of smaller and lighter Frequency Division Duplex (FDD) Massive MIMO O-RUs.
The company is also showcasing several compact and power-efficient O-RUs powered by Sierra. As uplink traffic increases due to growing high-bandwidth applications such as live video and user-generated content, networks are facing uplink capacity constraints. MNOs are evaluating FDD Massive MIMO to address uplink-limited scenarios, particularly in low-band spectrum. However, radio unit size, weight, and cost have remained key deployment barriers.
“Uplink traffic is growing faster than downlink traffic and will accelerate in the era of physical AI. There’s a strong need for uplink capacity in the critical low bands where FDD Massive MIMO can make all kinds of devices work better. This integration makes FDD Massive MIMO more practical for real-world upgrades,” said Joe Madden, principal analyst at Mobile Experts.
Sierra addresses these constraints at the architectural level through integrated PIM cancellation. In FDD systems, downlink transmissions generate PIM products that fall within the uplink receive band, reducing receiver sensitivity and throughput. Conventional systems rely on high-performance cavity filters to mitigate PIM effects, but these filters increase size, weight, and cost. By cancelling up to 20 dB of PIM per receive path using advanced signal processing, Sierra enables the use of smaller and lighter ceramic filters instead of bulky cavity filters. This approach reduces radio unit complexity while maintaining carrier-grade performance.
“Uplink demand is rising faster than network capacity, driving operators to look at FDD Massive MIMO as a practical way to relieve uplink congestion. But OEMs are challenged to deliver that capability without excessive cost and complexity,” said Puneet Sethi, senior vice president of MaxLinear’s Network Infrastructure & Carrier BU. “Sierra is already a proven carrier-grade solution for single- and multi-band macro radio units. Now, by using PIM cancellation to eliminate the need for bulky cavity filters, Sierra is enabling OEMs to build simpler, lighter FDD Massive MIMO radios that operators can deploy at scale to address the uplink demand challenge.”