TIDUF00 November   2021

 

  1.   Description
  2.   Resources
  3.   Features
  4.   Applications
  5.   5
  6. 1System Description
    1. 1.1 Why Radar?
    2. 1.2 Key System Specifications
  7. 2System Overview
    1. 2.1 Block Diagram
      1. 2.1.1 Automated Parking Software Block Diagram
    2. 2.2 Highlighted Products
      1. 2.2.1 AWR1843AOP Single-Chip Radar Solution
      2. 2.2.2 mmWave SDK
    3. 2.3 System Design Considerations
      1. 2.3.1 Usage Case Geometry and Sensor Considerations
      2. 2.3.2 AWR1843AOP Antenna
      3. 2.3.3 Processing Chain
    4. 2.4 Chirp 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
        1. 3.2.2.1 Use Case – Vehicle, Bicycle, Pedestrian Detection
        2. 3.2.2.2 Use Case – Traffic Cone, Grocery Cart, Sign Pole, Pipe, Shrub
        3. 3.2.2.3 Use Case – Pedestrian Standing in Empty Parking Space
        4. 3.2.2.4 Use Case – Pedestrian Standing Next to Car
        5. 3.2.2.5 Use Case – Empty Parking Space
        6. 3.2.2.6 Use Case – Cross Traffic Alert
        7. 3.2.2.7 Use Case – Parking Block, Curb Detection
  9. 4Design Files
    1. 4.1 Design Database
    2. 4.2 Schematic, Assembly, and BOM
  10. 5Software Files
  11. 6Related Documentation
    1. 6.1 Trademarks

2.3.1 Usage Case Geometry and Sensor Considerations

The AWR1843AOP combines the AWR1843 silicon with a wide FOV antenna-on-package.

The AWR1843 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 key performance parameters of the AWR1843AOP radar front end depend on the following:

  • Configuration of the transmit signal
  • Configuration and performance of the RF transceiver
  • The design of the antenna array
  • Available memory and processing power.

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

  • Maximum Range
    • Range is estimated from a beat frequency in the de-chirped signal 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 experience aliasing.
  • Velocity resolution
    • This is defined as the minimum velocity difference over which the detector can distinguish two individual point targets that are also 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 can affect the effective antenna gain as a function of angle. The field of view is typically specified separately for the 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.