Coding in a MIMO communication system
AssigneeAlcatel-Lucent USA Inc.
InventorAlexei Ashikhmin
Life of this patent
Estimating the term…
Abstract
A method of receiving information includes receiving a vector of signal values for a transmitted codeword in antennas of a MIMO receiver array in each of a sequence of time slots. Each vector forms one row of a matrix Y. Each antenna receives the signal values of one column of the matrix Y over the sequence of time slots such that one of the antennas receives the signal values of each column of the matrix Y. The method also includes evaluating a vector S(0, . . . , 0) for an associated zero m-component vector (0, . . . , 0). The vector S(0, . . . , 0) is given by a Hadamard transform of the diagonal part of the square matrix Y·Y†.
Claims20
An apparatus for transmitting a sequence of messages via a MIMO channel, comprising:
- a MIMO transmitter having an array of antennas, being configured to select any codeword of a codebook, and being configured to select one of the codewords in response to receiving each message of the sequence, each codeword being a matrix;
- and
- wherein for each one of the selected codewords the transmitter is configured to transmit signals from the antennas in a series of time slots corresponding to the one of the selected codewords such that each antenna transmits one column of the one of the selected codewords and such that one row of the one of the selected codewords is transmitted in each of the time slots of the corresponding series;
- and
- wherein the transmitter is configured such that each of the codewords is a matrix U(λ|a1, . . . , am|b1, . . . , bm) and is configured such that the associated product U(λ|a1, . . . , am|b1, . . . , bm)·U(λ|a1, . . . , am|b1, . . . , bm) is a projection operator P(λ|a1, . . . , am|b1, . . . , bm) that is a unitary transformation of ½[I+λE(a1, . . . , am|b1, . . . , bm)], each (a1, . . . , am|b1, . . . , bm) being a nonzero vector whose components are zero or one, each E (a1, . . . , am|b1, . . . , bm) being a direct product of m ej's, each ej satisfying:
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A method of transmitting a sequence of messages from a MIMO array of antennas, comprising:
- for each message of the sequence of messages, selecting a codeword from a preselected codebook, each codeword of the codebook being a matrix;
- for each one of the selected codewords, transmitting signals from the MIMO array of antennas in a series of time slots corresponding to the one of the selected codewords such that the MIMO array transmits one column of the one of the selected codewords from each antenna and such that one row of the one of the selected codewords is transmitted in each of the time slots of the corresponding series;
- and
- wherein each of the codewords of the codebook is equal to a matrix U(λ|a1, . . . , am|b1, . . . , bm) left multiplied by a unitary matrix and right multiplied by a unitary matrix, the columns of the U(λ|a1, . . . , am|b1, . . . , bm)'s being given by
- uj1{circle around (x)} . . . {circle around (x)}ujm's, wherein each ujk satisfies
- u
- j
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- v
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- v
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- ,
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- 0
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- .
A method of receiving information, comprising:
- in each of a sequence of time slots, receiving a vector of signal values for a transmitted codeword in antennas of a MIMO receiver array, each vector forming one row of a matrix Y, each antenna receiving the signal values of one column of the matrix Y over the sequence of time slots such that one of the antennas receives the signal values of each column of the matrix Y;
- and
- for a zero in-component vector (0, . . . , 0), evaluating an associated vector S(0, . . . , 0), the vector S(0, . . . , 0) being given by a Hadamard transform of the diagonal part of the square matrix Y·Y†.
An apparatus, comprising:
- a MIMO receiver including an array of antennas, the receiver being configured to receive a vector of signal values for a transmitted codeword via the antennas in each of a sequence of time slots, each vector forming one row of a matrix Y, the receiver being such that each antenna receives the signal values of one column of the matrix Y over the sequence of time slots such that the signal values of each column of the matrix Y are received in one of the antennas of the array;
- and
- wherein the receiver is configured to evaluate a vector S(0, . . . , 0) for a zero m-component vector (0, . . . , 0) from the received signal values, the vector S(0, . . . , 0) being given by a Hadamard transform of the diagonal part of the square matrix Y·Y†.
Dependencies are inferred from the claim text.