Receiver in wireless communication system and diversity combining method thereof
View Patent ↗A diversity combining method applied by a receiver in a wireless communication system is provided, including: acquiring baseband signals of receiving channels corresponding to multiple receiving antennas, and combining multiple acquired baseband signals according to a Maximal-Ratio Combining (MRC) principle at an intermediate frequency and/or within an equalizer and/or after the equalizer. Further a receiver in a wireless communication system is provided. By means of the technical solutions of the disclosure, it is possible to improve a demodulation threshold and the demodulation sensitivity of a microwave system.
1. A diversity combining method applied by a receiver in a wireless communication system, the method comprising:
acquiring baseband signals of receiving channels corresponding to multiple receiving antennas; and
combining, according to a Maximal-Ratio Combining (MRC) principle, the acquired baseband signals within an equalizer to obtain a diversity combined baseband signal with improved diversity gain by using a formula:
r
n
=
∑
i
=
1
L
S
N
R
i
r
n
(
i
)
;
wherein r n represents the diversity combined baseband signal, SNR i represents a Signal Noise Ratio (SNR) of a received signal corresponding to an ith receiving antenna, and r n (i) represents a baseband signal of a receiving channel corresponding to the ith receiving antenna.
2. The diversity combining method applied by a receiver in a wireless communication system according to claim 1 , wherein the acquired baseband signals of the receiving channels corresponding to the multiple receiving antennas are baseband signals processed by matched filtering.
3. A receiver in a wireless communication system, comprising:
an equalizer configured to acquire baseband signals of receiving channels corresponding to multiple receiving antennas, and combine, according to a Maximal-Ratio Combining (MRC) principle, the acquired baseband signals to obtain a diversity combined baseband signal with improved, diversity gain by, using a formula:
r
n
=
∑
i
=
1
L
S
N
R
i
r
n
(
i
)
;
wherein r n represents the diversity combined baseband signal, SNR i represents a Signal Noise Ratio (SNR) of a received signal corresponding to an ith receiving antenna, and r n (i) represents a baseband signal of a receiving channel corresponding to the ith receiving antenna.
4. The receiver in a wireless communication system according to claim 3 , further comprising:
a filter configured to perform matched filtering processing on the baseband signals of the receiving channels corresponding to the multiple receiving antennas, which are acquired from a Radio Frequency (RF) front end, and transmit processed signals to the first combination module.
5. A diversity combining method applied by a receiver in a wireless communication system, the method comprising:
performing intermediate frequency processing and matched filtering processing on a baseband signal of a receiving channel corresponding to an ith receiving antenna to obtain a time domain baseband signal r n (i) , wherein i=1, . . . , L;
performing Fast Fourier Transform (FFT) on r n (i) to obtain a frequency domain signal R k (i) ; and
performing combination within a frequency-domain equalization module according to a Maximal-Ratio Combining (MRC) principle using below formula to obtain an FFT value S k of a transmitted symbol:
S
k
=
∑
i
=
1
L
c
k
(
i
)
R
k
(
i
)
;
wherein c k (i) is a coefficient when FFT is performed on the transmitted symbol, where an optimal coefficient is obtained according to a minimum error principle and using a formula below:
c
k
(
i
)
=
(
σ
d
σ
n
(
i
)
)
2
(
H
k
(
i
)
)
*
1
+
∑
l
=
1
L
(
(
σ
d
σ
n
(
l
)
)
2
H
k
(
l
)
2
)
;
wherein H k (i) is a frequency domain response of a channel corresponding to the i th antenna; and wherein σ d /σ n (l) is a Signal to Interference plus Noise Ratio (SINR).
6. The diversity combining method applied by a receiver in a wireless communication system according to claim 5 , the method further comprising:
performing Inverse Fast Fourier Transform (IFFT) on S k to convert the frequency domain signal to the time domain signal, thus obtaining an equalized signal s n .
7. A receiver in a wireless communication system, comprising:
a filter configured to perform intermediate frequency processing and matched filtering processing on a baseband signal of a receiving channel corresponding to an i th receiving antenna to obtain a time domain baseband signal r n (i) , wherein i=1, . . . , L;
a first FFT module configured to perform FFT on r n (i) to obtain a frequency domain signal R k (i) ; and
a second combination module configured to perform combination within a frequency-domain equalization module according to a Maximal-Ratio Combining (MRC) principle using a formula below to obtain an FFT value S k of a transmitted symbol:
S
k
=
∑
i
=
1
L
c
k
(
i
)
R
k
(
i
)
;
wherein c k (i) is a coefficient when FFT is performed on the transmitted symbol, where an optimal coefficient is obtained according to a minimum error principle and using a formula below:
c
k
(
i
)
=
(
σ
d
σ
n
(
i
)
)
2
(
H
k
(
i
)
)
*
1
+
∑
l
=
1
L
(
(
σ
d
σ
n
(
l
)
)
2
H
k
(
l
)
2
)
;
wherein H k (i) is a frequency domain response of a channel corresponding to the i th antenna; and wherein σ d /σ n (l) is a Signal to Interference plus Noise Ratio (SINR).
8. The receiver in a wireless communication system according to claim 7 , further comprising:
a first IFFT module configured to perform IFFT on S k to convert the frequency domain signal to the time domain signal, thus obtaining an equalized signal s n .