Table of Contents

octoFade overview




Channel models


Ordering information

octoFade-3GPP 2G/3G and LTE channel emulation RTL

octoFade-3GPP is FPGA based wireless channel emulator that operates in real-time on a stream of input IQ samples, producing a stream of output IQ samples.

octoFade 3GPP Block Diagram

octoFade RTL block diagram

octoFade-3GPP emulates multipath and Doppler fading and AWGN per 3GPP certification specifications, supporting GSM, UMTS and LTE channel models.

octoFade-3GPP is available as

  • RTL for integration into test equipment
  • Ready-to-use integrated into the Altera Stratix IV based PCIe card (see octoFade-FPGA) with Digital I/O connectors carrying IQ sample streams

The RTL is easily customizable and expandable, based on the available logic resources. RTL is provided in VHDL and can be implemented in ASIC or FPGA. The octoFade-3GPP can be easily integrated with off-the-shelf RF test equipment for testing through the device antenna terminals.


  • Operates in real-time on digital IQ samples
  • Supports
    • 3GPP models for UMTS, GSM and LTE
    • Variety of SISO/MIMO channel configurations
    • SNR/AWGN


  • R&D and QA testing of 2G/3G/LTE radios
  • Integration with RF signal generators, analyzers and other test equipment

octoScope can customize the octoFade-3GPP RTL to fit a desired hardware platform and customer requirements. 802.11n/ac channel models, currently available as C software, will be available as RTL soon.

Parameter Specification
Digital IQ inputs (N) Up to 8 (16-bit)
Digital IQ outputs (M) Up to 4 (16-bit)
MIMO channels Up to 2 independently configured MIMO channels
Maximum number of TDL paths Up to 16 paths
Maximum number of taps per TDL (T) Up to 18
Maximum number of taps 144 taps total (N x M x T)
Tap specifications 0 to -40dB; 0.1dB resolution
10ns delay resolution
30us max delay range
3GPP channel models LTE: EPA 5Hz; EVA 5Hz;EVA 70Hz; ETU 70Hz; ETU 300Hz; MBSFN
GSM: RAx; HTx; TUx; EQx; TIx
UMTS: PA3; PB3; VA30; VA120; MBSFN
Moving propagation, birth-death, high-speed train
Custom channel models Arbitrary fading profiles can be implemented in software and loaded into the FPGA via register interface.
Distortion Better than -50dBc
AWGN SNR: -10 to +25dB; 0.1dB resolution
Bandwidth: Up to 20MHz, per 3GPP standard requirements
Fading Types: Rician/Rayleigh
Spectrum: Classical Doppler
Shift: 0.1 – 1000Hz; 1Hz resolution
Control Interface 32-bit register memory map
FPGA resources (dual channel 4x2 MIMO topology example with 18 taps per MIMO path) Logic: ~84k ALUTs
Memory: 6-7 Mb
Multipliers: 300

octoScope can modify any of these specifications and integrate octoFade-RTL into a desired FPGA platform, for example Altera Stratix IV GX FPGA Development Kit, 530 Edition (DK-DEV-4SGX230N) or National Instruments LabVIEW FPGA module. The octoFade solution can be easily integrated with off-the-shelf RF test equipment, such as VSA/VSG, for testing through the device antenna ports or over-the-air. Please contact sales@octoscope.com with any inquiries