Method for processing information representative of a transmission channel by a radio equipment device, receiving equipment and associated computer program

A receiver for setting a multiple-input, multiple-output (MIMO) precoder of a transmitter by processing information representative of a transmission channel between radio equipment corresponding to the receiver comprising a plurality (r) of antennas and at least one transmitting antenna, and radio equipment corresponding to the transmitter comprising a plurality (t) of transmission antennas paired with the MIMO precoder and at least one receiving antenna, the number of transmitting antennas (t) being greater than the number of receiving antennas (r), said information comprising a matrix (H) representative of the transmission channel estimated beforehand from at least one received data signal, said receiver comprising:

• a processor;
• and
• a non-transitory computer-readable medium comprising instructions stored thereon, which when executed by the processor configure the device to perform acts comprising:
• obtaining at least one pair of eigen characteristics of the product of the conjugate transpose of the channel matrix with the channel matrix (H*H), consisting of non-zero eigenvalues (λi) and eigenvectors (ui) associated with said eigenvalues;
• measuring a signal to noise ratio (ρ) in the transmission channel;
• calculating at least one eigenvalue (μi) of a autocorrelation matrix of symbols on transmission, according to a criterion of maximizing a capacity (C) of the transmission channel, from the eigenvalues (λi) obtained, arranged in descending order and the measurement of the signal to noise ratio (ρ), according to the following equations:
• 0
• ≤
• p
• ≤
• argmax
• m
• ≤
• r
• ⁢
• m
• -
• 1
• (
• 1
• +
• (
• rt
• ⁢
• ⁢
• ρ
• )
• -
• 1
• ⁢
• ∑
• k
• ≤
• m
• ⁢
• λ
• k
• -
• 1
• )
• >
• (
• rt
• ⁢
• ⁢
• ρ
• ⁢
• ⁢
• λ
• m
• )
• -
• 1
• μ
• i
• =
• 1
• p
• ⁢
• (
• 1
• +
• ∑
• j
• =
• 1
• p
• ⁢
• 1
• rt
• ⁢
• ⁢
• ρ
• ⁢
• ⁢
• λ
• j
• )
• -
• 1
• rt
• ⁢
• ⁢
• ρ
• ⁢
• ⁢
• λ
• i
• ⁢
• ⁢
• for
• ⁢
• ⁢
• 1
• ≤
• i
• ≤
• p
• μ
• i
• =
• 0
• ,
• for
• ⁢
• ⁢
• p
• <
• i
• ≤
• t
• p being the number of calculated eigenvalues, and m, k and i being positive integers, the non-zero eigenvalue (μi) of the autocorrelation matrix being associated with the same eigenvector (μi) as the eigenvalue (λi) of the product of the conjugate transpose of the channel matrix with the channel matrix (H*H);
• transmitting, to the transmitter information representative of said at least one calculated non-zero eigenvalue (μi) associated with the eigenvector (μi);
• and
• receiving symbols distributed by the transmitter on transmission over the plurality (t) of transmission antennas of the transmitter, based on said information.

A non-transitory computer-readable medium comprising a computer program stored thereon, which includes instructions for implementing a method for setting a multiple-input, multiple-output (MIMO) precoder of a transmitter when executed by a processor of a processing device of a receiver, wherein the instructions configure the receiver to perform acts comprising:

• processing information representative of a transmission channel between radio equipment, corresponding to the receiver, comprising a plurality (r) of receiving antennas and at least one transmitting antenna, and radio equipment corresponding to the transmitter comprising a plurality (t) of transmission antennas paired with the MIMO precoder and at least one receiving antenna, the number of transmission antennas (t) being greater than the number of receiving antennas (r), said information comprising a matrix (H) representative of the transmission channel estimated beforehand from at least one received data signal, said processing comprising:
• obtaining at least one pair of eigen characteristics of the product of the conjugate transpose of the channel matrix with the channel matrix (H*H), consisting of non-zero eigenvalues (λi) and eigenvectors (μi) associated with said eigenvalues;
• obtaining a measurement of a signal to noise ratio (ρ) in the transmission channel;
• calculating at least one eigenvalue (μi) of an autocorrelation matrix of symbols on transmission, according to a criterion of maximizing a capacity (C) of the transmission channel, from the eigenvalues (λi) obtained, arranged in descending order and the measurement of the signal to noise ratio (ρ), according to the following equations:
• 0
• ≤
• p
• ≤
• argmax
• m
• ≤
• r
• ⁢
• m
• -
• 1
• (
• 1
• +
• (
• rt
• ⁢
• ⁢
• ρ
• )
• -
• 1
• ⁢
• ∑
• k
• ≤
• m
• ⁢
• λ
• k
• -
• 1
• )
• >
• (
• rt
• ⁢
• ⁢
• ρ
• ⁢
• ⁢
• λ
• m
• )
• -
• 1
• μ
• i
• =
• 1
• p
• ⁢
• (
• 1
• +
• ∑
• j
• =
• 1
• p
• ⁢
• 1
• rt
• ⁢
• ⁢
• ρ
• ⁢
• ⁢
• λ
• j
• )
• -
• 1
• rt
• ⁢
• ⁢
• ρ
• ⁢
• ⁢
• λ
• i
• ⁢
• ⁢
• for
• ⁢
• ⁢
• 1
• ≤
• i
• ≤
• p
• μ
• i
• =
• 0
• ,
• for
• ⁢
• ⁢
• p
• <
• i
• ≤
• t
• p being the number of calculated eigenvalues, and m, k and i being positive integers, the non-zero eigenvalue (μi) of the autocorrelation matrix being associated with the same eigenvector (ui) as the eigenvalue (λi) of the product of the conjugate transpose of the channel matrix with the channel matrix (H*H);
• transmitting, to the transmitter, information representative of said at least one calculated non-zero eigenvalue (μi) associated with the eigenvector (ui);
• and
• receiving symbols distributed by the transmitter on transmission over the plurality (t) of transmission antennas of the transmitter, based on said information.