Digital Waveform Systems, Inc.

MIMO-DPR Radar System

MIMO-DPR Radar System

The MIMO-DPR Radar System is a “non-linear” digital radar system. Multiple-Input, Multiple-Output Digital Plenoptic Radar (MIMO-DPR) is a new class of digital radar. The architecture of this “non-linear” digital radar system is composed of three basic radar subsystems. These radar subsystems are:

  • CDMA Subsystem:
    		•

    The Code Division Multiple Access (CDMA) Spread-Spectrum Subsystem provides the radar with cellular single-frequency, multi-user, multi-access, and code-diversity capabilities.
  • MIMO Subsystem:
    		•

    The Multiple-Input, Multiple-Output (MIMO) Antenna Array Subsystem provides the radar with space-diversity capabilities.
  • ISS Subsystem:
    		•

    The Intermodulation Spread Spectrum (ISS) Waveform Subsystem provides the radar with “non-linear” waveform capabilities.

Details of the MIMO-DPR Radar System are presented in the sections below.

Figure 1 portrays the concepts of a radar system operating with “active”, “collective”, “synergistic”, and “cooperative” interoperations, intercommunications, and interconnectivity.

First, the MIMO-DPR Radar System decomposes the radar-space into a system of independent CDMA time-of-flight rays. Second, the MIMO-DPR Radar System operates using a complete and comprehensive computational system of discrete triangulations. The system is a multi-level system of intra-radar and inter-radar triangulations. This system of discrete CDMA time-of-flight triangulations enables high-reliability networking and connectivity. This networking and connectivity enables high quality-of-service (i.e. QoS) synergistic radar networks.

“Synergistic” means that the MIMO-DPR Radar System is a “see and be seen” radar system. Every radar sees every other radar. “Synergistic” means that the MIMO-DPR Radar System is cooperative.

Business Development Strategy

MIMO-DPR is envisioned as a future-generation coherent, code division multiple access (CDMA), “spread-spectrum”, MIMO radar system. A target application area for the MIMO-DPR Radar System is next-generation automotive radar markets.

The MIMO-DPR System offers three tiers of radar connectivity:

Figure 2 illustrates that the MIMO-DPR System is cooperative and synergistic. As illustrated, MIMO-DPR enables radar-to-radar systems that “actively” and “collectively” interoperate and intercommunicate. The MIMO-DPR architecture enables high-density, high-performance, cellular multi-user, anti-jam, and low probability of intercept automotive radar systems.

MIMO-DPR Radar System

High-Density, Anti-Jam, and Low Probability of Intercept Automotive Radar Systems

 

 

Figure 2: MIMO-DPR enables “See and be Seen”, High-Density, Anti-Jam, and Low Probability of Intercept Automotive Radar Systems

MIMO-DPR Computational System

Computationally, the basis of the radar system is a discrete geometric system of triangulations. "Discrete" means that the radar geometry is discretized. Discrete triangulations enable a radar concept called “plenoptic radar”.

The MIMO-DPR Radar System introduces two “innovative” radar architectural concepts. These radar architectural concepts are:

CDMA Radar System

CDMA Radar is advanced pseudo-noise based, auto-correlation system. The auto-correlation system is enabled by the MIMO-ISS Waveform System. The ISS waveform improves radar signal processing capabilities, features, and performances in a three key areas. These key areas are:

Key CDMA Radar channel performance advantages include the following:

CDMA Radar introduces a radar architectural concept called “radar densification” (i.e. number of radars per unit area). Radar densification enables the support of high-density, cooperative, and synergistic radar capabilities. Cooperative and synergistic means that radar-to-radar that the systems “actively” and “collectively” interoperate and intercommunicate.

Plenoptic Radar

Plenoptic Radar is a computational system. The system is a vector-based, computational geometry, convex optimization, coherent, code division multiple access (CDMA) spread-spectrum MIMO digital radar system. Each CDMA encoded signal represents a unique geometric ray of the radar system. These rays are referred to as “active plenoptic” rays.

Computationally, the MIMO-DPR uses a discrete geometry algorithm system composed of finite sets of discrete points, lines, triangles, vectors, and other geometric objects that are representations of discrete abstract radar objects. This computational geometric system offers superior algorithmic and operational performance.

MIMO Cellular Radar System

The MIMO-DPR Radar System is a cellular, single-frequency CDMA-based radar concept. As a MIMO-based radar concept, the MIMO-DPR Radar System is a coherent space, time, code, and waveform diversity concept. This integrated diversity concept enables superior capabilities compared with a standard and/or conventional phased array radar technologies.

The MIMO-DPR Radar System is a coherent radar system. Coherent means that the transmitter and receiver antennas are collocated. Coherent MIMO radar concepts allow higher resolution, higher sensitivity for target detection and imaging radar. As such, the MIMO-DPR Radar System offers superior with better parameter identifiability. Moreover, the MIMO-DPR Radar System operates using a space, time, code, and waveform diversity concepts.

This conceptual architecture is unique to plenoptic radar systems.

Concept of the Digital Plenoptic Radar System

Plenoptic Radar is a coherent, code division multiple access (CDMA), “spread-spectrum”, MIMO radar system.

As a MIMO radar system, the system is composed of multiple transmitting and receiving antenna systems. As a signal processing system, MIMO is a spatial diversity radar system. Key advantages of spatial diversity and/or antenna multiplicity includes: (1) improved target detection and imaging resolution, (2) improved sensitivity to detect slowly moving targets and ground-moving target indication (GMTI), and (3) improved angle estimation accuracy.

Figure 3 below shows the basic multiple-input, multiple-output architectural concepts of the MIMO-DPR Radar System.

MIMO-DPR Radar System

MIMO Radar Two-Target Conceptual Model

Basic MIMO Radar Architecture

Basic RDM ( Range Doppler Matrix)

 

 

 

 

Figure 3: MIMO-DPR enables Multi-Target Radar Detection Systems and Radar Imaging Systems

Conventional MIMO radar technology defines two architectures: (1) Statistical MIMO Radar and (2) Coherent MIMO Radar. In Statistical MIMO Radar systems, the antennas are distributed such that the radar cross sections are statistically independent. In Coherent MIMO Radar systems, the antennas are closely-packed and/or co-located such that the radar cross sections are coherent.

MIMO-DPR operates as a Coherent MIMO Radar System. The MIMO-DPR System operates coherently in time, distance, direction, frequency, and power.

Concept of Plenoptics

Plenoptics is a concept adapted from computational photography. The word plenoptic is derived from Latin. Plenoptic means “full image” or “full vision”. As such, the concept of digital plenoptic radar translates as follows:

Full “imaging” and “vision” means that a digital plenoptic radar system provides continuous “illumination of” and continuous “detection throughout” the full surveillance volume. This full surveillance volume concept is called super-parallax. Super-parallax is an active system of geometric optics. This active system is referred to as digital plenoptics.

“Digital plenoptics” means “digital parallax”.

Illustrated in Figure 3 above, as a radar system concept, plenoptics decomposes of the radar-space into a system of geometric rays. This system of geometric rays is implemented using a massive L-fold, multi-dimensional, diversity architecture. L-fold diversity is defined as the digital integration of space, time, frequency, and code division multi-access algorithms, techniques, and methods. This L-fold diversity architecture is the core concept of the MIMO-DPR system.

Computational Radar System

Computationally, MIMO-DPR is a vector-based, computational geometry, convex optimization, coherent, code division multiple access (CDMA) spread-spectrum MIMO Digital Radar System. MIMO-DPR is composed of three major systems. These systems are:

MIMO Radar

The MIMO-DPR System is a multiple-input, multiple-output (MIMO), digital communications radar system. Digital Communications means that the radar system operates using digital communications concepts such as digital constellations (i.e. Mary-QAM, Mary-PSK, and etc.), packets, algorithmic techniques, code division multiple access (CDMA) codes, and data structures.

MIMO means that the MIMO-DPR System operates using four canonical, computational geometric radar system architectures. These canonical, computational architectures and geometries are:

The key geometric and architectural Concepts & Characterizations of the Digital MIMO Radar System are presented in Table 1 below.

Digital MIMO Radar

 

MIMO Receiver Outputs

Single Output (SO)

Multiple Output (MO)

MIMO Transmitter Input

Single Input (SI)

SISO

(Single Input – Single Output)

SIMO

(Single Input – Multiple Output)

  • Conventional/Classical/Traditional Bi-static Radar Geometry
  • Multi-Receiver (Rx) Radar Geometry

 

 

Key DPR Geometry Characteristics:

Key DPR Geometry Characteristics:
  • No Spatial Diversity
  • Rx Spatial Diversity
  • Time-Code Diversity
  • Space-Time-Code Diversity
  • Time-Code Computational Geometry
  • Space-Time-Code Computational Geometry
  • Time-Code Convex Optimization
  • Space-Time-Code Convex Optimization

 

 

Multiple Input (MI)

MISO

(Multiple Input – Single Output)

MIMO

(Multiple Input – Multiple Output)

  • Multi-Transmitter (Tx) Radar Geometry
  • Multi-Transmitter (Tx) Radar Geometry
  • Multi-Receiver (Rx) Radar Geometry

 

 

Key DPR Geometry Characteristics:

Key DPR Geometry Characteristics:
  • Tx Spatial Diversity
  • Tx-Rx Spatial Diversity
  • Space-Time-Code Diversity
  • Space-Time-Code Diversity
  • Space-Time-Code Computational Geometry
  • Space-Time-Code Computational Geometry
  • Space-Time-Code Convex Optimization
  • Space-Time-Code Convex Optimization

 

 

Table 1: Concepts & Characterizations of Digital MIMO Radar Geometries

Radar Waveform Metrics

In the MIMO-DPR System two figures of merit are used to quantify the autocorrelation properties of a waveform. These metrics are as follows:

Figure 4 below shows simulations of the PSLR for the MIMO-DPR Radar System that range from 50 dB to 200 dB. Larger PSLR values means that there is greater suppression of peak sidelobes. Greater peak sidelobes suppression means better target discrimination, tracking, and resolution.

The MIMO-DPR System introduces proprietary concepts, algorithms, techniques, and mathematical formulations that provide excellent PSLR suppression.

These PSLR concepts and algorithms provide improved target detection and imaging resolution, improved sensitivity to detect slowly moving targets and ground-moving target indication (GMTI), and improved angle estimation accuracy.

MIMO-DPR Radar System

MIMO-DPR Peak Side-Lobe Suppression Ratio (PSLR)

40 dB

Peak Side-Lobe Suppression Ratio

 

50 dB

Peak Side-Lobe Suppression Ratio

 

100 dB

Peak Side-Lobe Suppression Ratio

 

200 dB

Peak Side-Lobe Suppression Ratio

 

Figure 4: MIMO-DPR enables Radar Systems which achieve Peak Side-Lobe Suppression Ratios (PSLRs) Ranging from 50 dB to 200dB

Plenoptics Array System Architecture

MIMO-DPR spatial diversity parallelism is realized using a new class of active electronically scanned array (AESA) technology. This AESA matrix architecture is called a digital plenoptic array. More specifically, the system is referred to as an active electronic plenoptic array (AEPA). The AEPA system architecture consists of a massive array of coded matrix antenna elements. As a communications system, the AEPA system functions as an integrated Space Division Multi-Access (SDMA) array. This SDMA array system is composed of the following types of modules: (1) multi-transmitter, (2) multi-receiver, and (3) code-division multi-access (CDMA) module elements.

First, the MIMO-DPR system defines an innovative AEPA antenna layer. Second, integrated SDMA-CDMA algorithms perform and direct the plenoptic detection, ranging, and parametric operations of the radar system. Lastly, the ISS waveform integrated with geometric algorithms improves target detection and imaging.

Proprietary

The MIMO-ISS System is proprietary and confidential to Digital Waveform Systems, Incorporated. Detailed information and description of the concepts, algorithms, mathematical formulations, architectural diagrams, signal-flow diagrams, and technologies, of the MIMO-ISS System, can be provided and disclosed subject to mutual non-disclosure agreements.

If you are interested in learning more about the details, specifications, and capabilities of the MIMO-ISS System you can contact us at Digital Waveform Systems, Incorporated.