Documentation

Squared_Link. Brief description

Additional products

• Squared_Modem. Evaluation kit

Software

• SDR_Surfer. Software environment

Squared_Link. SDR platform

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Overview

SDR platform Squared_Link is a digital transceiver intended for implementation in wireless modems. Embedded software of Squared_Link is a multimode OFDM transceiver based on OFDM technology, it can work in wideband, narrowband modes, spread spectrum mode and fragmented spectrum mode. Hardware of Squared_Link is based on Altera's Cyclone V FPGA and AD9361 transceiver. Evaluation kit Squared_Modem includes RF board and motherboard with Ethernet interface, it can be used as standalone solution too.

Features

• Communication technology: scaled OFDM1024 with unique technology for mixing of wideband, narrowband, spread spectrum and fragmented spectrum signals in one air link frame. (Learn more about OFDM_MultiMode).
• Duplexing mode: TDD or FDD.
• Bandwidth: 1-20 MHz (smoothly variable).
• Modulation: BPSK; QPSK; 8QAM; 16QAM; 64QAM; 256QAM.
• FEC: LDPC.
• Maintaining coding rates: 1/2; 2/3; 3/4; 5/6.
• Spread spectrum mode features:
• spreading factor: any even number in range from 2 to 106;
• SNR (BER=10^-6, spreading factor 106): -17 dB;
• maximal signal search duration: 1 sec.
• MIMO features (maintenance depends on hardware version):
• number of antennas: 2;
• working modes: SISO, SIMO, MISO, MIMO;
• space time code in MISO and MIMO modes: Alamouti code.
• Air link frame duration: 2-20 ms.
• Cyclic prefix duration: 1/32; 1/16; 1/8; 1/4.
• Carrier frequency range: 70-6000 MHz.
• Maximal TX output power: -6 dBm.
• RX sensitivity depends on bandwidth, modulation, FEC rate and LNA performance (see Squared_Link. Brief description).
• Information bandwidth depends on bandwidth, modulation and FEC rate (see Squared_Link. Brief description).
• Network configurations: P2P; PMP; mesh networking.
• Interfaces:
• universal: GMII; RGMII; MII; RMII; 1,2,4,8 bits wide bus;
• control: USB, UART;
• debug: JTAG.
• Downloadable by user:
• preamble modulation sequence;
• spreading codes for spread spectrum mode;
• pilot subcarriers modulation sequence;
• pilot and informational subcarriers location.
• Available statistical information about channel:
• input signal samples;
• spectrum of useful signal;
• spectrum analyzer mode;
• RSSI;
• timing offset;
• frequency offset;
• FEC FER;
• FEC decoder iterations number;
• TX-RX range calculated from signal delay.
• Power: 3.3 V.
• Available hardware versions:
• 5CEBA5 FPGA (only SISO mode with bandwidth up to 12 MHz);
• 5CEBA7 FPGA (SISO, SIMO, MISO);
• 5CEBA9 FPGA (SISO, SIMO, MISO, MIMO).
• Power consumption: 2.9 W (12 MHz bandwidth, TDD mode 50/50, 5CEBA7 FPGA).
• Physical dimensions: 55x40x8 mm.