Method of high-bitrate wireless communication with a multi-antenna receiver
A method is provided for transmitting data between a transmitter having M>=1 transmit antenna(s), and one or more receivers having a total of N>=2 receive antennas. In the method, the data are transmitted using OFDM/OQAM modulation having L>=1 subcarriers. The transmitted data are pre-encoded using a pre-encoding matrix, the size of which is M s N and which is dependent on a zero-forcing matrix and on a spatial multiplexing matrix.
1. A method comprising:
wireless transmission, by a wireless transmitter furnished with M≧1 transmit antenna(s), of data intended for R≧1 wireless receiver(s), each wireless receiver No. r, where r=1, . . ., R being furnished with N r receive antennas, where Σ r=1 R N r =N and N≧2, in which said data are transmitted by using an OFDM/OQAM modulation comprising L≧1 sub-carriers, said wireless transmission comprising:
for at least one value of the integer l, where 0≦l≦L−1, a prior step of obtaining an estimate Ĥ (I) of the transfer matrix, of dimension N·M, of the MIMO channel between said transmit antennas and said receive antennas, and
for said value of l, the following steps:
placement of data to be transmitted in a data vector X (l) with N real components,
calculation of a coded data vector S (l) ≡W (I) ·X (l) with M components, where W (I) is a precoding matrix of dimension M·N depending:
on a Zero-Forcing matrix Q, and
on the real part of a matrix representing a spatial multiplexing P (I) followed by a channel transfer Ĥ (I) , and
transmission of said coded data vector S (l) on the sub-carrier l, by transmitting the m-th component, where m=1,2, . . ., M, of the vector S (l) from the m-th transmit antenna.
2. The method as claimed in claim 1 , wherein W (I) is of the form:
W (I) =Q· ( Ĥ (I) ·P (I) ), where Q =( Ĥ (I) ) H ·[Ĥ (I) ·( Ĥ (I) ) H ] −1 .
3. The method as claimed in claim 1 , wherein said spatial multiplexing is carried out by using the following MMSE precoder:
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4. The method as claimed in claim 1 , wherein said spatial multiplexing is carried out by using the following time-reversal precoder:
P (I) =( Ĥ (I) ) H .
5. The method of claim 1 , further comprising:
for said value of l, at least one of the wireless receivers No. r, where r=1, . . ., R, implements the following steps:
reception of said coded data,
determination of a received vector Y (r) (l) , and
obtaining of a decoded data vector T (r) (l) on the basis of said received vector Y (r) (l) ,
where the received vector Y (r) (l) is the vector with N r real components whose n-th component, where n=1,2, . . .,N r , is equal to the symbol associated with the sub-carrier l received on the n-th receive antenna, after OFDM/OQAM demodulation and extraction of the real part.
6. A wireless transmitter comprising:
M≧1 transmit antenna(s),
means for transmitting data intended for R≧1 wireless receiver(s), each wireless receiver No. r, where r=1, . . .,R being furnished with N r receive antennas, where Σ r=1 R N r =N and N >2, by means of an OFDM/OQAM modulation comprising L≧1 sub-carriers,
means for obtaining, for at least one value of the integer l, where0≦l≦L−1, an estimate Ĥ (I) of the transfer matrix, of dimension N·M,of the MIMO channel between said transmit antennas and said receive antennas, and
for said value of l, means for:
placing data to be transmitted in a data vector X (l) with N real components,
calculating a coded data vector S (l) ≡W (I) ·X (l) with M components, where W (I) is a precoding matrix of dimension M·N depending:
on a Zero-Forcing matrix Q, and
on the real part of a matrix representing a spatial multiplexingP (I) followed by a channel transfer Ĥ (I) , and
transmitting said coded data vector S (l) on the sub-carrier l, by transmitting the m-th component, where m=1,2, . . . , M, of the vector S (l) from the m-th transmit antenna.
7. The wireless transmitter of claim 6 , wherein W (i) is of the form:
W (I) =Q · ( Ĥ (I) ·P (I) ), where Q =( Ĥ (I) ) H ·[Ĥ (I) ·( Ĥ (I) ) H ] −1 .
8. The wireless transmitter as claimed in claim 6 , wherein said spatial multiplexing is carried out by using the following MMSE precoder:
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9. The wireless transmitter as claimed in claim 6 , wherein said spatial multiplexing is carried out by using the following time-reversal precoder:
P (I) =( Ĥ (I) ) H .
10. A system comprising:
a wireless transmitter furnished with M≧1 transmit antenna(s),comprising means for transmitting data to R≧1 wireless receiver(s), eachwireless receiver No. r, where r=1, . . . , R being furnished with N r receive antennas, where Σ r=1 R N r =N and N≧2, by using an OFDM/OQAM modulation comprising L≧1 sub-carriers, as well as means for obtaining,for at least one value of the integer l, where 0≦l≦L−1, an estimate Ĥ (I) of the transfer matrix, of dimension N·M, of the MIMO channel between said transmit antennas and said receive antennas, said wireless transmitter further comprising, for said value of l, means for:
placing data to be transmitted in a data vector X (l) with N real components,
calculating a coded data vector S (l) ≡W (I) ·X (l) with M components, where W (I) is a precoding matrix of dimension M·N depending:
on a Zero-Forcing matrix Q and
on the real part of a matrix representing a spatial multiplexing P (I) followed by a channel transfer Ĥ (I) , and
transmitting said coded data vector S (l) on the sub-carrier l,by transmitting the m-th component, where m=1,2, . . . , M, ofthe vector S (l) from the m-th transmit antenna; and
said R wireless receiver(s), and wherein, for said value of l, at least one wireless receiver No. r, where r=1, . . . , R, comprises means for:
receiving said coded data,
determining a received vector Y (r) (l) and
obtaining a decoded data vector T (r) (l) on the basis of said received vector Y (r) (l) , where the received vector Y (r) (l) is the vector with N r real components whose n-th component, where n=1,2, . . . , N r , is equal to the symbol associated with the sub-carrier l received on the n-th receive antenna, after OFDM/OQAM demodulation and extraction of the real part.
11. An irremovable or partially or totally removable non-transitory computer-readable medium for storing data, comprising computer program code instructions stored thereon for execution of a method of wireless transmission, by a wireless transmitter comprising a processor and M≧1 transmit antenna(s), of data intended for R≧1 wireless receiver(s), each wireless receiver No. r, where r=1, . . . , R being furnished with N r receive antennas, where Σ r=1 R N r =N and N≧2, in which said data are transmitted by using an OFDM/OQAM modulation comprising L≧1 sub-carriers when the instructions are executed by the processor, said wireless transmission comprising:
for at least one value of the integer l, where 0≦l≦L−1, a prior step of obtaining an estimate Ĥ (I) of the transfer matrix, of dimension N·M of the MIMO channel between said transmit antennas and said receive antennas, and
for said value of l, the following steps:
placement of data to be transmitted in a data vector X (l) with N real components,
calculation of a coded data vector S (l) ≡W (I) ·X (l) with M components, where W (I) is a precoding matrix of dimension M·N depending:
on a Zero-Forcing matrix Q, and
on the real part of a matrix representing a spatial multiplexing P (I) followed by a channel transfer Ĥ (I) , and
transmission of said coded data vector S (l) on the sub-carrier l, by transmitting the m-th component, where m=1,2, . . . , M, of the vector S (l) from the m-th transmit antenna.