Methods and systems for combined cyclic delay diversity and precoding of radio signals
AssigneeTelefonaktiebolaget L M Ericsson (publ)
InventorsGeorge Jöngren, Bo Göransson
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Abstract
In a transmitter or transceiver, signals can be precoded by multiplying symbol vectors with various matrices. For example, symbol vectors can be multiplied with a first column subset of unitary matrix which spreads symbols in the symbol vectors across virtual transmit antennas, a second diagonal matrix which changes a phase of the virtual transmit antennas, and a third precoding matrix which distributes the transmission across the transmit antennas.
Claims35
A method for transmitting information signals having a plurality of symbol vectors associated therewith on a radio channel comprising:
- precoding said symbol vectors by multiplying said symbol vectors with:
- a first column subset of a unitary matrix which spreads symbols in said symbol vectors across all virtual transmit antennas,
- a second diagonal matrix which changes a phase of said virtual transmit antennas, and
- a third precoding matrix which distributes transmit energy across physical transmit antennas,
- wherein said symbol vectors are first multiplied by said first column subset of unitary matrix, next multiplied by said second diagonal matrix and then multiplied by said third precoding matrix,
- further processing said precoded symbol vectors to generate said information signals, and
- transmitting said information signals.
A transmitter for transmitting information signals having a plurality of symbol vectors associated therewith on a radio channel comprising:
- a plurality of physical transmit antennas;
- a processor for precoding said symbol vectors by multiplying said symbol vectors with:
- a first column subset of a unitary matrix which spreads symbols in said symbol vectors across all virtual transmit antennas,
- a second diagonal matrix which changes a phase of said virtual transmit antennas, and
- a third precoding matrix which distributes transmit energy across said physical transmit antennas,
- wherein said symbol vectors are first multiplied by said first column subset of unitary matrix, next multiplied by said second diagonal matrix and then multiplied by said third precoding matrix
- and for further processing said precoded symbol vectors to generate said information signals;
- and
- a transmit chain of elements for transmitting said information signals.
A method for equalizing received information signals having a plurality of symbol vectors associated therewith comprising:
- forming a channel estimate associated with said received information signals by multiplying an initial channel estimate with a plurality of matrices, said plurality of matrices including:
- a first column subset of a unitary matrix,
- a second diagonal matrix, and
- a third precoding matrix, and
- equalizing said information signals using said formed channel estimate, wherein said initial channel estimate is first multiplied by said first column subset of the unitary matrix, next multiplied by said second diagonal matrix and then multiplied by said third precoding matrix.
A processor for forming a channel estimate associated with received information signals by multiplying an initial channel estimate with a plurality of matrices, said plurality of matrices including:
- a first column subset of a unitary matrix,
- a second diagonal matrix, and
- a third precoding matrix, and
- wherein said processor uses said formed channel estimate to equalize said received information signals, and
- wherein said initial channel estimate is first multiplied by said first column subset of unitary matrix, next multiplied by said second diagonal matrix and then multiplied by said third precoding matrix.
A transmitter for transmitting information signals having a plurality of symbol vectors associated therewith on a radio channel comprising:
- a plurality of physical transmit antennas;
- a processor for precoding said symbol vectors by multiplying said symbol vectors with:
- a first column subset of a unitary matrix which spreads symbols in said symbol vectors across all virtual transmit antennas,
- a second diagonal matrix which changes a phase of said virtual transmit antennas, and
- a third precoding matrix which distributes transmit energy across said physical transmit antennas, and for further processing said precoded symbol vectors to generate said information signals by mapping precoded symbols to resource blocks to be transmitted via at least one of said transmit antennas and distributing said resource blocks over the resource element grid of an orthogonal frequency division multiplexing (OFDM) type of transmission;
- and
- a transmit chain of elements for transmitting said information signals,
- wherein said symbol vectors are first multiplied by said first column subset of unitary matrix, next multiplied by said second diagonal matrix and then multiplied by said third precoding matrix.
Dependencies are inferred from the claim text.