Progressive parallel interference canceller and method and receiver thereof
First Claim
1. A progressive parallel interference canceller (PPIC), adaptable to a receiver in a multiple input multiple output (MIMO) communication system based on an orthogonal frequency-division multiplexing (OFDM) modulation technique, wherein the receiver performs a plurality of iterations, the PPIC comprising:
- a plurality of subchannel interference reconstruction units, wherein the kth subchannel interference reconstruction unit corresponding to a rth receiving antenna generates a kth subchannel interference reconstruction signal SICI,r,k(i) corresponding to the rth receiving antenna during the ith iteration according to (2×
i−
2) subchannel frequency-domain estimation signals Ŝ
t,((k−
i+1))N(1), Ŝ
t,((k−
i+2))N(2), . . . , Ŝ
t,((k−
2))N(i−
2), Ŝ
t,((k−
1))N(i−
1), Ŝ
t,((k+1))N(i−
1), Ŝ
t,((k+2))N(i−
2), . . . , Ŝ
t,((k+i−
2))N(2), Ŝ
t,((k+i−
1))N(1), wherein i is an integer greater than 1, the subchannel frequency-domain estimation signal Ŝ
t,q(x) represents a qth subchannel frequency-domain estimation signal corresponding to a tth transmitting antenna generated during the xth iteration, and ((•
))N represents a calculation of dividing by N to obtain a remainder, N is a number of subchannels in the MIMO communication system, k is an integer between 0 and (N−
1), x is an integer between 1 and (i−
1), and q=k−
i+x or q=k+i−
x; and
a plurality of subchannel interference cancellation units, wherein the kth subchannel interference cancellation unit corresponding to the rth receiving antenna is coupled to the kth subchannel interference reconstruction unit corresponding to the rth receiving antenna, and the kth subchannel interference cancellation unit obtains a kth subchannel frequency-domain signal Y′
r,k(i) corresponding to the rth receiving antenna according to a kth subchannel frequency-domain reception signal Yr,k and the kth subchannel interference reconstruction signal SICI,r,k(i) corresponding to the rth receiving antenna during the ith iteration.
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Abstract
A progressive parallel interference canceller (PPIC) and a method and a receiver thereof are illustrated. The PPIC reconstructs each subchannel interference reconstruction signal through several iterations and subtracts the corresponding subchannel interference reconstruction signal from each subchannel frequency-domain reception signal to obtain a subchannel frequency-domain signal. Thereby, according to the present disclosure, inter-channel interference can be cancelled without re-performing channel coding or estimating the signal to noise ratio (SNR) or frequency offset.
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Citations
29 Claims
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1. A progressive parallel interference canceller (PPIC), adaptable to a receiver in a multiple input multiple output (MIMO) communication system based on an orthogonal frequency-division multiplexing (OFDM) modulation technique, wherein the receiver performs a plurality of iterations, the PPIC comprising:
-
a plurality of subchannel interference reconstruction units, wherein the kth subchannel interference reconstruction unit corresponding to a rth receiving antenna generates a kth subchannel interference reconstruction signal SICI,r,k(i) corresponding to the rth receiving antenna during the ith iteration according to (2×
i−
2) subchannel frequency-domain estimation signals Ŝ
t,((k−
i+1))N (1), Ŝ
t,((k−
i+2))N (2), . . . , Ŝ
t,((k−
2))N (i−
2), Ŝ
t,((k−
1))N (i−
1), Ŝ
t,((k+1))N (i−
1), Ŝ
t,((k+2))N (i−
2), . . . , Ŝ
t,((k+i−
2))N (2), Ŝ
t,((k+i−
1))N (1), wherein i is an integer greater than 1, the subchannel frequency-domain estimation signal Ŝ
t,q(x) represents a qth subchannel frequency-domain estimation signal corresponding to a tth transmitting antenna generated during the xth iteration, and ((•
))N represents a calculation of dividing by N to obtain a remainder, N is a number of subchannels in the MIMO communication system, k is an integer between 0 and (N−
1), x is an integer between 1 and (i−
1), and q=k−
i+x or q=k+i−
x; anda plurality of subchannel interference cancellation units, wherein the kth subchannel interference cancellation unit corresponding to the rth receiving antenna is coupled to the kth subchannel interference reconstruction unit corresponding to the rth receiving antenna, and the kth subchannel interference cancellation unit obtains a kth subchannel frequency-domain signal Y′
r,k(i) corresponding to the rth receiving antenna according to a kth subchannel frequency-domain reception signal Yr,k and the kth subchannel interference reconstruction signal SICI,r,k(i) corresponding to the rth receiving antenna during the ith iteration. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A receiver, adaptable to a MIMO communication system based on an OFDM modulation technique, wherein the receiver performs a plurality of iterations and comprises:
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a plurality of receiving antennas; a plurality of OFDM demodulators, wherein each of the OFDM demodulators is coupled to one of the receiving antennas; a PPIC, coupled to the OFDM demodulators, the PPIC comprising; a plurality of subchannel interference reconstruction units, wherein the kth subchannel interference reconstruction unit corresponding to the rth receiving antenna generates a kth subchannel interference reconstruction signal SICI,r,k(i) corresponding to the rth receiving antenna according to (2×
i−
2) subchannel frequency-domain estimation signals Ŝ
t,((k−
i+1))N (1), Ŝ
t,((k−
i+2))N (2), . . . , Ŝ
t,((k−
2))N (i−
2), Ŝ
t,((k+1))N (i−
1), Ŝ
t,((k+2))N (i−
2), Ŝ
t,((k−
1))N (i−
1), . . . , Ŝ
t,((k+i−
2))N (2), Ŝ
t,((k+i−
1))N (1) during the ith iteration, wherein i is an integer greater than 1, the subchannel frequency-domain estimation signal represents the qth subchannel frequency-domain estimation signal corresponding to a tth transmitting antenna generated during the xth iteration, ((•
))N represents a calculation of dividing by N to obtain a remainder, N is a number of subchannels in the MIMO communication system, k is an integer between 0 and (N−
1), x is an integer between 1 and (i−
1), and q=k−
i+x or q=k+i−
x; anda plurality of subchannel interference cancellation units, wherein the kth subchannel interference cancellation unit corresponding to the rth receiving antenna is coupled to the kth subchannel interference reconstruction unit corresponding to the rth receiving antenna, and the kth subchannel interference cancellation unit obtains a kth subchannel frequency-domain signal Yr,k(i) corresponding to the rth receiving antenna according to a kth subchannel frequency-domain reception signal Yr,k and the kth subchannel interference reconstruction signal SICI,r,k(i) corresponding to the rth receiving antenna during the ith iteration; and a MIMO detector, coupled to the subchannel interference reconstruction units and the subchannel interference cancellation units, for determining a plurality of bits b0, b1, . . . , and bMT−
1 corresponding to kth subchannels of the transmitting antennas according to the kth subchannel frequency-domain signals Y′
1,k(i), Y′
2,k(i), . . . , and Y′
R,k(i) of the receiving antennas when the PPIC performs the ith iteration, wherein M is a bit modulation order, R is a number of the receiving antennas, T is a number of the transmitting antennas, and the bits bM(t−
1), bM(t−
1)+1, . . . , and bMt−
1 corresponding to the kth subchannel of the tth transmitting antenna are used for determining the subchannel frequency-domain estimation signal Ŝ
t,k(i). - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20, 21)
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22. A progressive parallel interference cancellation method, adaptable to a receiver in a MIMO communication system based on an OFDM modulation technique, wherein the receiver performs a plurality of iterations, the progressive parallel interference cancellation method comprising:
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generating a kth subchannel interference reconstruction signal SICI,r,k(i) corresponding to the rth receiving antenna according to (2×
i−
1) subchannel frequency-domain estimation signals Ŝ
t,((k−
i+1))N (1), Ŝ
t,((k−
i+2))N (2), . . . , Ŝ
t,((k−
2))N (i−
2), Ŝ
t,((k−
1))N (i−
1), Ŝ
t,((k+2))N (i−
2), Ŝ
t,((k+1))N (i−
1), . . . , Ŝ
t,((k+i−
2))N (2), Ŝ
t,((k+i−
1))N (1), during the ith iteration, wherein i is an integer greater than 1, the subchannel frequency-domain estimation signal Ŝ
1,q(x) represents the qth subchannel frequency-domain estimation signal corresponding to a tth transmitting antenna generated during the xth iteration, ((•
))N represents a calculation of dividing by N to obtain a remainder, N is a number of subchannels in the MIMO communication system, k is an integer between 0 and (N−
1), x is an integer between 1 and (i−
1), q=k−
i+x or q=k+i−
x; andobtaining a kth sub channel frequency-domain signal Y′
r,k(i) corresponding to the rth receiving antenna according to a kth subchannel frequency-domain reception signal Yr,k and the kth subchannel interference reconstruction signal SICI,r,k(i) corresponding to the rth receiving antenna during the ith iteration. - View Dependent Claims (23, 24, 25, 26, 27, 28, 29)
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Specification