Modem System Test Engineer - Wireless Technologies and Ecosystems |

Join the Wireless Technologies and Eco-Systems (WTE) team and drive wireless innovations that impact millions of users worldwide! We design, validate, and integrate cutting-edge wireless technologies that enrich everyday experiences across our entire product ecosystem.

We are seeking a passionate, detail-oriented Modem Systems Test Engineer with a focus on Wireless Coexistence (COEX). In this role, you will be at the forefront of validating multi-radio platforms ensuring seamless concurrent operation between cellular technologies (LTE, 5G NR FR1/FR2) and adjacent radios such as Wi-Fi, Bluetooth, Ultra-Wideband (UWB), and GNSS. If you thrive in a fast-paced environment solving complex cross-radio interference, desense, and protocol arbitration challenges, we would love to hear from you.

In this role, you will be responsible for end-to-end system testing, performance characterization, and failure triage of advanced cellular baseband and multi-radio coexistence features. You will bridge baseband protocol software, RF hardware, and connectivity systems to guarantee robust real-world performance under hostile interference conditions.

You will rely on deep trace analysis, lab simulation, RF instrumentation, and automation to uncover edge-case performance degradation, desense mechanisms, and protocol timing collisions. Working cross-functionally with system architecture, firmware, protocol development, RF design, and carrier engineering, you will drive test coverage, root-cause complex issues, and influence system-level mitigation designs. Coexistence Test Design & Execution: Define, develop, and execute comprehensive test plans targeting in-device coexistence (IDC), inter-radio arbitration, multi-SIM / multi-active scenarios, and concurrent multi-band operation (LTE/5G NR with Wi-Fi, Bluetooth, UWB, and GNSS).

RF & Protocol Root-Cause Analysis: Analyze baseband protocol traces (PHY, MAC, RLC, PDCP, RRC), air-interface captures, and RF measurements to root-cause desense, throughput degradation, scheduling conflicts, dropped calls, and handover anomalies.

Mitigation & Feature Validation: Evaluate and validate dynamic coexistence mechanisms, including power back-off, time-division multiplexing (TDM) / frequency-division multiplexing (FDM) filtering, antenna switching/sharing, and adaptive link management.

Intelligent Test Automation: Develop robust, scalable test automation scripts and post-processing analytics pipelines in Python to automate test execution, KPI aggregation (BLER, throughput, latency), and anomaly detection.

Testbed & Environment Integration: Set up, calibrate, and maintain sophisticated lab testbeds incorporating cellular network emulators (call boxes), RF matrix switches, combiners, spectrum analyzers, and wireless channel emulators.

Cross-Functional Collaboration: Partner closely with baseband firmware, connectivity software, RF systems engineering, and hardware teams to reproduce lab/field defects, validate fixes, and verify 3GPP and internal performance specifications.Education: Bachelor's or Master's degree in Electrical Engineering, Computer Engineering, Telecommunications, or a related field.

Cellular Protocol Stack Expertise: Deep technical understanding of 3GPP LTE and 5G NR (Rel-15/16+) across Layer 1 (PHY), Layer 2 (MAC/RLC/PDCP), and Layer 3 (RRC/NAS).

Coexistence & RF Fundamentals: Strong grasp of RF transceiver architectures, in-device coexistence (IDC), antenna isolation, harmonics, intermodulation distortion (IMD), receiver desense, and multi-radio interference mitigation techniques.

Hands-on Validation Experience: Proven track record of system test, integration, or validation using commercial wireless network emulators (e.g., Keysight, Rohde & Schwarz, Anritsu) and RF instrumentation (spectrum analyzers, signal generators, power meters).

Automation & Scripting: Strong proficiency in Python for test automation, instrument control (SCPI/VISA), and automated parsing/analysis of large log datasets.

Analytical Problem Solving: Demonstrated capability to triage and root-cause multi-layer failures across hardware, firmware, and protocol interactions.Prior experience testing Dual-SIM / Dual-Active (DSDS/DSDA) or complex Cellular scenarios with simultaneous connectivity radios. Working knowledge of 3GPP in-device coexistence specifications (e.g., Rel-11+ IDC mechanisms, autonomous denial, auxiliary information reporting). Experience with non-cellular wireless standards (Wi-Fi 6/6E/7 - 802.11ax/be, Bluetooth 5.x, UWB, NFC, GNSS). Familiarity with data analysis and visualization libraries (Pandas, NumPy, Plotly/Matplotlib) for large-scale test KPI dashboards. Contributions to 3GPP standardization (RAN4, RAN5) or carrier certification testing for coexistence and performance. Proficiency in diagnosing complex system-level issues through lab/field experimentation, analytics, and log analysis. Excellent analytical & critical thinking skills, Excellent communication & interpersonal skills.