Solutions

With the advancement of wireless communications, radar detection, and electronic reconnaissance technologies, the demand for multi-channel synchronous signal acquisition has become increasingly critical. LUOWAVE has developed a high-precision 16-channel synchronous signal acquisition system based on eight USRP-LW N321 devices. This system enables parallel acquisition and precise time-frequency alignment, supporting key applications such as spatial spectrum direction finding and MIMO systems. 1. System Description The 16-channel synchronous signal acquisition system is built on LUOWAVE USRP-LW N321 platform, consisting of USRP-LW N321 units, a host controller, a network switch, an OctoClock-LW-G clock source, and a signal generator. The system employs eight USRP-LW N321 devices (totaling 16 channels), all connected via 10G fiber optics to the switch and synchronized by an OctoClock-LW-G clock source. A signal generator provides the local oscillator (LO) signal, which is distributed via a power splitter to ensure phase coherence better than 1° across all channels. A host server with 100G fiber connectivity enables real-time monitoring and data acquisition, delivering high-precision synchronized signal data for advanced research applications such as high-accuracy spatial spectrum direction finding and MIMO transceiver system design. 2. System Components (1) Programmable SDR (USRP-LW N321) The USRP-LW N321 serves as the RF front-end, covering a frequency range from 3 MHz to 6 GHz with up to 200 MHz instantaneous bandwidth per channel. Its high-precision synchronization interfaces, distributed architecture support, and programmable flexibility make it ideal for multi-channel synchronous acquisition systems. (2) Host Controller A high-performance server equipped with a 100G accelerator card is recommended for real-time baseband signal processing and high-speed data transfer, ensuring robust support for complex system prototyping and theoretical validation. In this system, we use SDR-LW 4940 for host controller. (3) OctoClock-LW-G Clock Source Provides 10 MHz and PPS references to synchronize all USRP-LW N321 units, ensuring precise timing and trigger alignment. (4) Signal Generator An external LO signal is generated and split into eight paths via a power divider, feeding into the LO inputs of all USRP-LW N321 units to maintain phase synchronization. (5) Network Switch Connects the server and eight USRP-LW N321 devices via 10G fiber optics, while the server interfaces through a 100G fiber link for high-throughput data transmission. 3. System Topology & Connections (1) Clock & PPS Trigger Connections The OctoClock-LW-G supplies eight 10 MHz clock outputs and eight PPS sync signals.  (2) LO Distribution A high-stability signal generator feeds an 8-way power splitter, delivering LO signals to all USRP-LW N321 units via equal-length cables to ensure frequency, phase, and time synchronization. (3) Data Connection SDR front-end data is transmitted to the server via 10G SFP+ interfaces. (4) RF Connections Each USRP-LW N321 supports two RX and two TX channels, connected via RF cables to an antenna array arranged in a specific configuration. 4. Key Specifications Frequency Range: 3 MHz – 6 GHz (asynchronous), 450 MHz – 6 GHz (synchronous) Signal Bandwidth: Up to 200 MHz (3 dB), max sampling rate of 250 Msps (configurable as integer submultiples of master clock: 200/245.76/250 MHz) Channels: Standard 16-channel setup (expandable) Storage: 64 TB SSD (supports 2-hour recording at 16 ch × 122.88 Msps) Phase Sync:

Overview Using open-source system platforms and hardware to study small-scale base stations is an important direction of research in the fields of radio and LTE wireless communications. Traditional commercial base station equipment is expensive, has long development cycles, high operational complexity, and cumbersome functionality changes. To address the issue of complex functionality changes and long development cycles in the study of LTE wireless communication base stations, the proposed solution adopts the open-source OAI 5G and srsRAN software systems and a software-defined radio (SDR) hardware platform to build real-time operating base stations for research on interactions with terminals. This approach avoids the issues of bulky and expensive base stations with long development cycles, improving the efficiency of research on base stations and terminal interactions. Solution Based on the USRP-LW/SDR-LW series of software-defined radio hardware, combined with software platforms such as srsRAN and OpenAirInterface (OAI) 5G, a 4G/5G simulation base station and terminal can be built. By using different models of software-defined radio hardware and various base station configuration parameters, different functionalities can be achieved. This system can fully simulate the end-to-end protocol stack, accurately model the base station, terminal, and core network, while complying with the corresponding 3GPP protocol specifications. It supports integration with commercial equipment (such as commercial terminals and core networks) and allows secondary development based on the protocol stack. Figure 1 shows the LTE system architecture, consisting of three parts: the core network (EPC), the base station (eNB), and the user (UE). Each part implements its corresponding functions according to the 3GPP LTE protocol stack. On the UE side, the architecture includes functions such as PHY, MAC, RLC, PDCP, and RRC. The UE communicates with the eNB for uplink and downlink data exchange via the air interface. In the middle is the eNB architecture, which includes the air interface with the UE and the S1-U and S1-MME interfaces with the core network. On the right side is the EPC, which consists mainly of network elements such as the MME, S-GW, and P-GW. Figure 2 shows the NR system architecture. The 5G radio interface inherits the 4G protocol stack, with an additional SDAP layer introduced in the user plane to mark Quality of Service (QoS). The 5G system architecture is also divided into three parts: the user (UE), the 5G base station (gNodeB), and the core network (5GC). The ng-eNB, gNodeB, and 5GC are connected through the NG interface.

Overview Large-scale Multiple-Input Multiple-Output (MIMO) technology is a key technology in 5G network communications. It utilizes large-scale antenna arrays to achieve efficient signal transmission and reception. By increasing the number of antennas, large-scale MIMO technology can significantly enhance the channel capacity and spectral efficiency of the system without requiring additional spectrum resources or transmit power. To realize the 5G vision and meet the critical performance requirements for spectral efficiency, it is essential to prototype and validate large-scale MIMO and other related technologies. Since computer-based simulations alone cannot address many of the complex unresolved issues, it is necessary to develop prototype systems that can operate in real-time under actual channel conditions and transmit/receive real RF signals. A hardware-in-the-loop (HIL) system, which combines simulation software on a computer with a software-defined radio (SDR) platform, can address these challenges, facilitating the transition from theoretical simulation to practical application and thereby accelerating the development of next-generation communication systems. Solution This solution is implemented using Luowave USRP-LW N321 platform, which primarily consists of the programmable RF front-end USRP-LW N321, servers, switches, and the clock source OctoClock-LW-G. Setup Diagram Recommended Model The USRP-LW N321 is a network software-defined radio that can provide reliability and fault-tolerant capabilities for deployment in large-scale and distributed wireless systems. It is a high-performance SDR that uses a unique RF design to offer 2 RX and 2 TX channels in a half-width RU size. The flexible synchronization architecture supports a 10 MHz clock reference, PPS time reference for external TX LO and RX LO inputs, enabling a phase-coherent MIMO test platform. OctoClock-LW-G is a device allocation system for high-precision clock sources. It is very useful for users who wish to establish a multi-channel system and synchronize to a common reference time. For instance, we can use OctoClock-G to perform coherent operations on USRP N210 and synchronize with the system. This enables many phased array applications, such as beamforming, super-resolution direction finding, diversity combination, or the design of MIMO transceivers.

5G Millimeter Wave USRP Solution Overview As the demand for ultra-high data transmission, low latency and large capacity in the mobile communication market is growing increasingly strong, the communication industry needs to develop other frequency bands of 5G wireless technology to alleviate the current pressure on wireless spectrum usage in networks.   The so-called 5G millimeter wave, according to the 3GPP 38.101 protocol, 5G NR mainly uses two frequency bands: FR1 frequency band and FR2 frequency band. The frequency range of FR1 frequency band is 450MHz - 6GHz, also known as the Sub-6GHz frequency band; the frequency range of FR2 frequency band is 24.25GHz - 52.6GHz, usually referred to as millimeter wave.     Advantages of 5G mmWave High speed and large capacity: mmWave can provide extremely high data transmission speed, with peak rate reaching 30 Gbps, supporting simultaneous connection of a large number of devices, and suitable for scenarios such as live streaming of high-definition video and virtual reality. Low latency: mmWave technology can achieve faster response by reducing communication latency. It is very friendly for scenarios that require real-time data transmission, such as autonomous driving and remote control. High directivity: mmWave has good directivity and narrow beams, which is conducive to precise positioning and transmission, and can improve signal security and reduce interference. All-weather characteristics: mmWave propagation is much less affected by climate, and has all-weather characteristics. Currently, USRP transceivers can send and receive RF signals below 6 GHz, covering the Sub6G frequency band. To meet the requirements of NR FR2, LUOWAVE has deeply customized mmWave expansion modules for USRP, which can upconvert intermediate frequency signals to mmWave frequency band, thereby helping users quickly establish 5G mmWave mobile communication systems.   Solution The 5G millimeter-wave communication system is built based on the USRP-LW/SDR-LW series of software-defined radio platforms, millimeter-wave expansion modules and its OpenAirInterface (OAI) 5G software platform. It has the function of simulating the 5G NSA/SA network environment and can support the exploration of related technologies for 5G millimeter-wave communication. Through using different types of software-defined radio hardware and different base station configuration parameters, different functions can be achieved. This system can fully simulate the end-to-end protocol stack, fully simulate base stations, terminals and core networks, and meet the corresponding 3GPP protocol specifications. It supports interfacing with commercial equipment and supports secondary development based on the protocol stack.   Setup Diagram Base station side: It is composed of one high-performance radio independent device SDR-LW 2974, one millimeter-wave expansion module up-conversion module and one down-conversion module, and two millimeter-wave horn antennas.     Terminal side: It is composed of a software-defined radio device USRP-LW B210, a millimeter-wave extension module up-conversion module, a down-conversion module, an upper computer, and two millimeter-wave horn antennas.         Related Products The processing requirements of 5G-NR are much higher than those of 4G, thus requiring high-performance SDR devices or even more advanced PCs as the host computer for USRP. Through the accompanying millimeter-wave expansion module and up-converter, continuous frequency conversion from 24GHz to 44GHz can be supported, meeting the research needs of 5G millimeter-wave communication. (1) SDR-LW SeriesThe SDR-LW series is a high-performance SDR standalone device launched by Luoguang Electronics. It consists of an onboard processor, FPGA, and RF front-end. By working in synergy with the Intel X86 processor and FPGA, the flexibility of software-defined radio equipment is enhanced. The host of the SDR-LW series device can run 5G base station/terminal software, and the front-end realizes signal transmission for base stations and terminal devices through horn antennas. The integrated design framework enables it to quickly build prototypes of high-performance mobile wireless communication systems. It is recommended to choose the SDR-LW 2974 and SDR-LW 3980 models: (2) USRP-LW SeriesUSRP-LW N321 is a high-performance software-defined radio device featuring an instantaneous bandwidth of up to 200 MHz RF front-end, supporting MIMO configuration, and equipped with high-speed ADC and DAC. It can handle complex signal processing tasks and meet diverse wireless communication requirements. Soft base stations and soft terminals are set up on the PC connected to USRP-LW N321 to implement NR wireless protocol stack functions. USRP-LW N321 completes digital-to-analog conversion and completes the transmit and receive functions at the RF end. The baseband processor of USRP-LW N321 adopts Xilinx Zynq-7100 SoC, integrating a large-scale user-programmable FPGA and dual-core ARM CPU, providing strong support for real-time and low-latency processing. By using SFP+ and QSFP+ ports, USRP-LW N321 can transmit high-throughput I/Q data streams to the host PC or FPGA coprocessor, meeting the requirements of high-speed data processing. It supports remote execution tasks, such as software update, restart, and factory reset, thereby simplifying the control and management of the radio network.

Overview As we enter the 6G era, wireless communication frequency bands are advancing towards higher ranges such as millimeter waves and terahertz, gradually overlapping with traditional radar sensing frequencies. Integrating sensing and communication on the same spectrum not only enhances the utilization of spectral resources but also alleviates the scarcity of traditional wireless spectrum resources. In simple terms, integrated sensing and communication technology involves adding radar-like capabilities (sensing) to our existing cellular mobile communication networks (communication), enabling the detection and tracking of surrounding objects such as drones, cars, or ships. In a narrow sense, integrated sensing and communication refers to communication systems capable of ranging, speed measurement, angle measurement, imaging, target detection, target tracking, and target recognition, which was initially termed "radar-communication integration." In a broader sense, integrated sensing and communication refers to communication systems that can perceive the attributes and states of all services, networks, users, terminals, and environmental objects, potentially surpassing the capabilities of traditional radar in sensing. Solution The overall architecture of the integrated sensing and communication system hardware platform is shown in Figure 1. In this setup, the SDR-LW/USRP-LW series software-defined radio hardware serves as the integrated sensing and communication transceiver. While transmitting signals to serve communication users, it also receives echo signals to enable the sensing of multiple targets. Recommended Model The SDR-LW series is a high-performance SDR (Software-Defined Radio) standalone device launched by Luoguang Electronics, consisting of an onboard processor, FPGA, and RF front-end. By leveraging the collaborative operation of the Intel X86 processor and FPGA, the flexibility of the software-defined radio equipment is enhanced. The all-in-one design framework allows for the rapid deployment of integrated sensing and communication systems, whether indoors or outdoors.