Method for processing radio-frequency signals received on r antennas, and corresponding reception method, decoding method, computer program and system

A method of receiving radio-frequency signals on R antennas, where R≥2, implementing a radio unit communicating with a base band processing unit, wherein the method comprises, implemented by the radio unit:

• for each of the antennas, obtaining a frequency representation of the radio-frequency signal received on the antenna, formed by a set of complex samples;
• demapping the frequency representations, identifying useful resource elements, carrying data, and reference resource elements, carrying at least one reference signal of a DeModulation Reference Signal (DMRS) type,
• a useful resource element carrying v data symbols, where v≥1 is the number of spatial layers used for transmitting the data,
• estimating a transmission channel of the radio-frequency signals and a noise-plus-interference covariance from the at least one reference signal,
• for at least one useful resource element, projecting a vector of R complex samples associated with the useful resource element, obtained respectively from each of the frequency representations, onto a vector of L projected samples, taking account of the estimation of channel and of the noise-plus-interference covariance, where R>L≥V,
• transmitting at least one item of control information, obtained from the channel estimation, to the base band processing unit, and
• transmitting the vector of L projected samples to the base band processing unit.

A method of decoding radio-frequency signals received on R antennas, where R≥2, implementing a radio unit communicating with a base band processing unit, wherein the method comprises, implemented by the base band processing unit:

• receiving at least one item of control information transmitted by the radio unit, obtained from an estimation of a transmission channel of the radio-frequency signals implemented by the radio unit, from at least one reference signal of a DeModulation Reference Signal (DMRS) type,
• receiving a vector of L complex samples, referred to as projected samples, transmitted by the radio unit, obtained by projecting a vector of R complex samples associated with a useful resource element, obtained respectively from each frequency representation of the radio-frequency signals, onto the vector of L projected samples, where R>L≥v, and v≥1 is the number of spatial layers used for transmitting the data,
• equalising the L projected samples, taking account of the at least one item of control information, and
• processing the equalised symbols.

System A system comprising at least one radio unit, configured to process radio-frequency signals received on R antennas, where R≥2, and at least one base band processing unit, wherein the radio unit comprises at least a first processor configured to:

• obtain a frequency representation of the radio-frequency signal received on each of the antennas, each frequency representation being formed by a set of complex samples;
• demap the frequency representations, identifying useful resource elements, carrying data, and reference resource elements, carrying at least one reference signal of a DeModulation Reference Signal (DMRS) type,
• a useful resource element carrying v data symbols, where v≥1 is the number of spatial layers used for transmitting the data,
• estimate a transmission channel of the radio-frequency signals and a noise-plus-interference covariance from the at least one reference signal,
• project a vector of R complex samples associated with a useful resource element, obtained respectively from each of the frequency representations, onto a vector of L complex samples, referred to as projected samples, taking account of the estimation of channel and of the noise-plus-interference covariance, where R>L≥v,
• transmit at least one item of control information, obtained from the channel estimation, to the base band processing unit,
• transmit the vector of L projected samples to the base band processing unit,
• and in that the base band processing unit comprises at least a second processor configured to:
• receive the at least one item of control information transmitted by the radio unit,
• receive the vector of L projected samples transmitted by the radio unit,
• equalise the L projected samples, taking account of the at least one item of control information,
• process the equalised symbols.