Methods and systems for near-field MIMO communications
AssigneeLattice Semiconductor Corporation
InventorFarshid Aryanfar
Life of this patent
Estimating the term…
Abstract
A near-field communication (NFC) system supports increased data rates using a multiple-input-multiple-output (MIMO) interface. Multiple receive antennas are positioned within the near field of multiple transmit antennas. The NFC system uses a combination of antenna spacing and polarizations to reduce correlation between channels, and thus improves performance by creating closer to ideal MIMO operation. Such system can also be operated as parallel SISO links with reduced cross-channel interference resulting in low power consumption.
Claims27
A communication system comprising:
- a transmitter circuit comprising:
- a data mapping unit to divide a transmit data signal into transmit parallel data streams;
- a plurality of transmitters connected to the data mapping unit, each transmitter tuned to a center frequency ƒ and wavelength λ, each transmitter to output a respective transmit data stream as a respective transmit modulated signal;
- and
- a plurality of transmit antennas, each connected to one or more respective transmitters to transmit the respective transmit modulated signal, the transmit antennas collectively transmitting the transmit modulated signals of the wavelength λ;
- wherein a respective largest physical dimension of each of the plurality of transmit antennas is Di, and wherein a greatest of the respective largest physical dimensions Di of the plurality of transmit antennas is a maximum dimension D;
- and
- a receiver circuit comprising a plurality of receive antennas, the receive antennas to receive respective receive modulated signals, wherein each receive antenna is spaced from a closest one of the transmit antennas by a distance less than the greater of 2D2/λ and λ/2π.
A method comprising:
- transmitting a plurality of differently polarized signals, including:
- dividing a transmit data signal into transmit parallel data streams using a MIMO mapping scheme,
- transmitting each transmit data stream using a respective transmitter tuned to a center frequency ƒ and wavelength λ to produce transmit modulated signals,
- feeding the transmit modulated signals to a plurality of transmit antennas, wherein a respective largest physical dimension of each transmit antenna is Di, and wherein a greatest of the respective largest physical dimensions of the plurality of transmit antennas is a maximum dimension D;
- and
- transmitting each of the transmit modulated signals using a respective polarization;
- receiving a plurality of differently polarized receive modulated signals using a plurality of receive antennas, wherein each receive antenna is spaced from a closest one of the transmit antennas by a distance of less than the greater of 2D2/λ and λ2/π.
A communication system comprising:
- a MIMO transmitter comprising transmit antennas to transmit a respective transmit modulated signal of wavelength λ;
- wherein a respective largest physical dimension of each of the transmit antennas is Di, and wherein a greatest of the respective largest physical dimensions Di of the transmit antennas is a maximum dimension D;
- and
- a MIMO receiver comprising receive antennas to receive modulated signals, wherein each receive antenna is spaced from a closest one of the transmit antennas by a distance less than the greater of 2D2/λ and λ/2π.
Dependencies are inferred from the claim text.