Context: Xiaomi and Malikie Innovations, which owns a large portfolio of former BlackBerry patents, are fighting each other in patent offices and courts around the world, including in India, where the Delhi High Court ordered Xiaomi to put up a $28.7 million security deposit (May 4, 2026 ip fray article). In Germany, Malikie is suing Xiaomi for infringement at the Munich I Regional Court over EP2879321 (“Method and system for signaling transmission layers for single user and multi user mimo”), a patent covering signaling methods for wireless systems that use multiple antennas at once. Xiaomi responded with a separate nullity action asking the Bundespatentgericht (Federal Patent Court) in Munich to strike the patent down.
What’s new: The Federal Patent Court has issued a qualified notice, a non-binding early opinion on the case, ahead of the oral hearing. In it, the court says it currently believes Xiaomi’s nullity challenge will succeed. The judges found that a technical document from a 2009 industry standards meeting already described the signaling method Malikie’s patent claims, meaning the patent as granted is likely not new. Most of the 22 backup versions of the patent Malikie put forward as fallback options fare no better, either because they add wording the original patent filing does not clearly support or because they still do not get around that same 2009 document.
Direct impact:
- The oral hearing on Xiaomi’s nullity action is not scheduled until June 30, 2027, so nothing is decided yet, and the court can still change its mind once both sides argue their case in person. But if the preliminary view holds, Malikie stands to lose the patent it is using to sue Xiaomi for infringement in Munich, and that infringement case would likely lose its basis too. The court has also invited both sides to think about settling before the hearing.
- The non-binding preliminary opinion makes it very likely that the infringement case will be stayed.
Wider ramifications: The case fits a pattern in German courts, where Xiaomi has fended off several patent infringement campaigns by getting the underlying patents thrown out or narrowed before trial ever starts, including three patents asserted by Nera Innovations (June 9, 2026 ip fray article). Malikie is a much bigger opponent than Nera, fighting Xiaomi across more jurisdictions at once, so a loss on this one German patent will not slow Malikie down much. Still, it is an early data point in a fight that also includes Malikie’s Munich UPC case against Xiaomi and the ongoing dispute in India.
What the patent covers
EP’321 describes a method used inside a phone, referred to as “user equipment”, that talks to a cell tower using several antennas at the same time, a setup known as MIMO. The patent explains how the tower tells the phone, through a signaling message called downlink control information, which of several possible transmission paths and reference signal patterns it should use, so the phone can correctly decode what is being sent to it. The stated goal is to make this signaling work well, whether the tower is serving just one phone on that data channel at a time, or several phones sharing it at once, and to let the network switch between the two modes.
Why the court has doubts
The court’s main problem with the patent is a document from a 2009 meeting of the 3GPP, the industry group that writes mobile phone standards. That document, filed months before the patent’s own priority date, already described sending this kind of signaling for both the single-phone and multi-phone setups, using a control message format built to handle two data streams at once. The court currently thinks that already covers everything claim 1 of the patent asks for, so the claim is likely not new.
Malikie’s 22 backup versions of the claim mostly run into one of two problems, according to the court. Some rely on wording that, on the court’s reading, the original patent application did not clearly support when it was first filed, which patent law does not allow being added back in later. Others narrow the claim without doing anything to get around the same 2009 document, in some cases even with the help of a second 2009 document that showed how to stretch the same signaling idea to cover more data streams than just two.
A long runway before anything is final
Both sides now have until August 26, 2026 to file further arguments or make final requests, with replies due by November 11, 2026, all still nearly a year ahead of the June 30, 2027 hearing. The court has warned that any late-filed arguments or amended claims after those deadlines can be rejected outright if the delay is not properly excused, and that it will not promise any extensions.
Court and counsel
Court: Federal Patent Court, 6th Senate. The qualified notice was signed by Deputy Chairman Dr. Söchtig.
Counsel for Xiaomi: Clifford Chance’s (ip fray firm profile) Dr. Stefan Richter and Maikowski & Ninnemann Patent Attorneys – Partnership mbB, Berlin.