TIDUEZ2 March   2021

 

  1.   Description
  2.   Resources
  3.   Features
  4.   Applications
  5.   5
  6. 1System Description
    1. 1.1 Key System Specifications
  7. 2System Overview
    1. 2.1 Block Diagram
      1. 2.1.1 Obstacle Detection Application Software Block Diagram
    2. 2.2 Highlighted Products
      1. 2.2.1 AWR1843AOP Single-Chip Radar Solution
    3. 2.3 Design Considerations
      1. 2.3.1 System Design Theory
        1. 2.3.1.1 Usage Case Geometry and Sensor Considerations
        2. 2.3.1.2 Antenna Configuration
        3. 2.3.1.3 Processing Chain
      2. 2.3.2 Configuration Profile
  8. 3Hardware, Software, Testing Requirements, and Test Results
    1. 3.1 Required Hardware and Software
      1. 3.1.1 Hardware
      2. 3.1.2 Software and GUI
    2. 3.2 Testing and Results
      1. 3.2.1 Test Setup
      2. 3.2.2 Test Results
  9. 4Design and Documentation Support
    1. 4.1 Design Files
    2. 4.2 Software
    3. 4.3 Documentation Support
    4. 4.4 Support Resources
    5. 4.5 Trademarks

2.3.1.1 Usage Case Geometry and Sensor Considerations

The AWR1843AOP combines the AWR1843AOP silicon with a wide FOV antenna on package. The AWR1843 silicon is a radar-based sensor that integrates a fast FMCW radar front end with both an integrated ARM R4F MCU and TI C674x DSP for advanced signal processing. The configuration of the AWR1843AOP radar front end depends on the configuration of the transmit signal and the configuration and performance of the RF transceiver and the available memory and processing power. This configuration influences key performance parameters of the system.

The key performance parameters at issue are listed with brief descriptions.

  • Range
    • Range is estimated from a beat frequency in the de-chirped signal that is proportional to the round trip delay to the target. For a given chirp ramp slope, the maximum theoretical range is determined by the maximum beat frequency that can be detected in the RF transceiver. The maximum practical range is then determined by the SNR of the received signal and the SNR threshold of the detector.
  • Range resolution
    • This is defined as the minimum range difference over which the detector can distinguish two individual point targets, which is determined by the bandwidth of the chirp frequency sweep. The higher the chirp bandwidth, the finer the range resolution.
  • Range Accuracy
    • This is often defined as a rule of thumb formula for the variance of the range estimation of a single point target as a function of the SNR.
  • Maximum velocity
    • Radial velocity is directly measured in the low-level processing chain as a phase shift of the dechirped signal across chirps within one frame. The maximum unambiguous velocity observable is then determined by the chirp repetition time within one frame. Typically this velocity is adjusted to be one-half to one-fourth of the desired velocity range to have better tradeoffs relative to the other parameters. Other processing techniques are then used to remove ambiguity in the velocity measurements, which will experience aliasing.
  • Velocity resolution
    • This is defined as the minimum velocity difference over which the detector can distinguish two individual point targets that also happen to be at the same range. This is determined by the total chirping time within one frame. The longer the chirping time, the finer the velocity resolution.
  • Velocity accuracy
    • This is often defined as a rule of thumb formula for the variance of the velocity estimation of a single-point target as a function of the SNR.
  • Field of view
    • This is the sweep of angles over which the radar transceiver can effectively detect targets. This is a function of the combined antenna gain of the transmit and receive antenna arrays as a function of angle and can also be affected by the type of transmit or receive processing, which may affect the effective antenna gain as a function of angle. The field of view is typically specified separately for the azimuth and elevation. The AWR1843AOP antennae have a field of view of ±70° in both azimuth and elevation.
  • Angular resolution
    • This is defined as the minimum angular difference over which the detector can distinguish two individual point targets that also happened to have the same range and velocity. This is determined by the number and geometry of the antennas in the transmit and receive antenna arrays. This is typically specified separately for the azimuth and elevation.
  • Angular accuracy
    • This is often defined as a rule of thumb formula for the variance of the angle estimation of a single point target as a function of SNR.