US 12,704,587 B2 · Joint sensing and communications using OFDM waveforms

Abstract

Various embodiments comprise systems, methods, architectures, mechanisms and apparatus providing a dual-function radar communication (DFRC) system a multiple-input multiple-output (MIMO) radar is configured to have only a small number of its antennas active in each channel use. Probing waveforms are of an orthogonal frequency division multiplexing (OFDM) type. OFDM carriers are divided into two groups, one group that is used by the active antennas in a shared fashion, and another group where each subcarrier is assigned to an active antenna in an exclusive fashion (e.g., private subcarriers). Target estimation is carried out based on the received and transmitted symbols. The system communicates information via the transmitted OFDM data symbols and the pattern of active antennas in a generalized spatial modulation (GSM) fashion. A multi-antenna communication receiver can identify the indices of active antennas via sparse signal recovery methods. The private subcarriers may be used to synthesize a virtual array for high angular resolution, and also for improved estimation on the active antenna indices.

Claims20

Dependent claims

A multiple-input multiple-output (MIMO) radar system, comprising:

a uniform linear array (ULA) transmit array having Nt active transmit elements, spaced apart by dt;
and
a transmitter processing stage, configured for transmitting Ns symbol-bearing sections via a plurality of active antennas, the transmitter processing stage:
identifying antennas to be active during the channel use iteration, each of the active antennas being associated with each of a first group of subcarriers to be used as shared subcarriers and a respective one private subcarrier;
performing OFDM modulation based on Ns shared subcarriers and one respective private subcarrier on the symbols of each active antenna, wherein the private subcarrier associated with a respective active antenna includes a non-zero symbol only at a symbol location corresponding to an index of the respective active antenna to enable thereby active transmit antenna identification at a receiver using sparse signal recovery;
converting the modulated subcarriers into analog signals;
and
upconverting each analog signal in accordance with a carrier frequency for transmission by a respective assigned active antenna.

5 more elements

A method for use by a multiple-input multiple-output (MIMO) radar system including a uniform linear array (ULA) transmit array having Nt active transmit elements, spaced apart by dt and configured for transmitting Ns symbol-bearing sections via a plurality of active antennas, the method comprising:

identifying antennas to be active during the channel use iteration, each of the active antennas being associated with each of a first group of subcarriers to be used as shared subcarriers and a respective one private subcarrier;
performing OFDM modulation based on Ns shared subcarriers and respective one private subcarrier on the symbols of each active antenna, wherein the private subcarrier associated with a respective active antenna includes a non-zero symbol only at a symbol location corresponding to an index of the respective active antenna to enable thereby active transmit antenna identification at a receiver using sparse signal recovery;
converting the modulated subcarriers into analog signals;
and
upconverting each analog signal in accordance with a carrier frequency for transmission by a respective assigned active antenna.

2 more elements

An apparatus, comprising:

a uniform linear array (ULA) transmit array having Nt active transmit elements, spaced apart by dt;
and
a transmitter processing stage, configured for transmitting Ns symbol-bearing sections via a plurality of active antennas, the transmitter processing stage:
identifying antennas to be active during the channel use iteration, each of the active antennas being associated with each of a first group of subcarriers to be used as shared subcarriers and a respective one private subcarrier;
performing OFDM modulation based on Ns shared subcarriers and respective one private subcarrier on the symbols of each active antenna, wherein the private subcarrier associated with a respective active antenna includes a non-zero symbol only at a symbol location corresponding to an index of the respective active antenna to enable thereby active transmit antenna identification at a receiver using sparse signal recovery;
converting the modulated subcarriers into analog signals;
and
upconverting each analog signal in accordance with a carrier frequency for transmission by a respective assigned active antenna.

5 more elements

Dependencies are inferred from the claim text.

Joint sensing and communications using OFDM waveforms

Life of this patent

Joint sensing and communications using OFDM waveforms

Life of this patent

Abstract

Claims20