摘要:
A method for removing ICI for a received symbol is provided. Firstly, a transmitted symbol is received via a wireless channel within a symbol time so as to obtain the received symbol. The transmitted symbol includes P identical original partial data, wherein P is a positive integer larger than 1. The received symbol includes P received partial data corresponding to the original partial data, respectively. Next, on a time domain at least two of the P received partial data are copied so as to obtain at least two copied partial data. Each copied partial data includes P copies of its corresponding received partial data. After that, an estimated ICI of the time domain is determined according to the product of a predetermined constant array and the difference between the copied partial data. Afterwards, the estimated ICI is subtracted from the received symbol so as to obtain an output symbol.
摘要:
An apparatus and method for cell acquisition and downlink synchronization acquisition in an OFDMA wireless communication system are provided. In an SS apparatus in a broadband wireless communication system, a preamble subcarrier acquirer extracts subcarrier values having a preamble code from an FFT signal. A multiplier code-demodulates the subcarrier values by multiplying the subcarrier values by a preamble code. A correlator calculates a plurality of differential correlations in the code-demodulated signal. An IFFT processor IFFT-processes the differential correlations by mapping the differential correlations to subcarriers. A maximum value detector detects a maximum value from the IFFT signal and calculates a timing offset using an IFFT output index having the maximum value.
摘要:
In one aspect of the invention, a carrier frequency offset (CFO) estimation method to estimate a CFO value of a received signal is provided, and the method comprises: receiving a preamble signal which includes several non-perfect repeat segments; applying an interpolation procedure to interpolate the perfect repeat point of one segment compared with the next segment or the previous segment; acquiring a delay correlation value based on the two perfect repeat signal segments and estimating the CFO value based on the delay correlation value.
摘要:
Methods and systems for providing generalized link adaptation in an orthogonal frequency-division multiple access wireless communications network can include determining a number of desired resource blocks (RBs) for each user of a plurality of users; calculating a maximal channel gain Gm for each RB of a plurality of RBs; reordering the plurality of RBs based on the Gm; assigning one of the plurality of RBs to the plurality of users one-by-one according to the reordering of the plurality of RBs; determining a priority list for assigning remaining unassigned RBs; assigning the remaining unassigned RBs to the plurality of users based on the priority list; and mapping a symbol or a packet to each assigned RB.
摘要:
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.
摘要:
A method, and device implementing the method, for adaptively allocating pilot signals in a wireless communication system. The method includes receiving channel data, including channel length (L) data, inter-carrier interference power (PICI) data, coherence time (CT) data, and a number of subcarriers (N). The method further includes selecting, when L is greater than a first channel length threshold (LTH1), a first number of pilot signals between a minimum value of L and a maximum number of pilot signals NP,MAX, wherein the first number of pilot signals NP are equally spaced in time according to the CT data, and equally spaced in frequency. Further, the method includes selecting, when L is less than LTH1 and PICI is less than a power threshold (PTH), a second number of pilot signals such that the second number of pilot signals is between the minimum value of L and NP,MAX, wherein the second number of pilot signals are equally spaced in time according to the CT data, and equally spaced in frequency. Finally, the method includes selecting, when L is less than LTH1 and PICI is greater than PTH, a third number of pilot signals such that the third number of pilot signals is equal to n times L (nL), wherein n is an integer, the third number of pilot signals being equally spaced in time according to the CT data, and allocated according to a cluster(n) clustered pilot scheme with a cluster size equal to n, the n-sized clusters being clustered in frequency.
摘要:
A multiple-input multiple-output detector and a detection method using the same are provided. The detection method includes following steps. First, a plurality of candidate results is provided by a plurality of detectors. Next, a channel condition and a detected criterion are provided. Finally, one of the candidate results is selected to serve as a detected result according to the channel condition and the selection criterion.
摘要:
Methods and systems for providing generalized link adaptation in an orthogonal frequency-division multiple access wireless communications network can include determining a number of desired resource blocks (RBs) for each user of a plurality of users; calculating a maximal channel gain Gm for each RB of a plurality of RBs; reordering the plurality of RBs based on the Gm; assigning one of the plurality of RBs to the plurality of users one-by-one according to the reordering of the plurality of RBs; determining a priority list for assigning remaining unassigned RBs; assigning the remaining unassigned RBs to the plurality of users based on the priority list; and mapping a symbol or a packet to each assigned RB.
摘要:
A method, and device implementing the method, for adaptively allocating pilot signals in a wireless communication system. The method includes receiving channel data, including channel length (L) data, inter-carrier interference power (PICI) data, coherence time (CT) data, and a number of subcarriers (N). The method further includes selecting, when L is greater than a first channel length threshold (LTH1), a first number of pilot signals between a minimum value of L and a maximum number of pilot signals NP,MAX, wherein the first number of pilot signals NP are equally spaced in time according to the CT data, and equally spaced in frequency. Further, the method includes selecting, when L is less than LTH1 and PICI is less than a power threshold (PTH), a second number of pilot signals such that the second number of pilot signals is between the minimum value of L and NP,MAX, wherein the second number of pilot signals are equally spaced in time according to the CT data, and equally spaced in frequency. Finally, the method includes selecting, when L is less than LTH1 and PICI is greater than PTH, a third number of pilot signals such that the third number of pilot signals is equal to n times L (nL), wherein n is an integer, the third number of pilot signals being equally spaced in time according to the CT data, and allocated according to a cluster(n) clustered pilot scheme with a cluster size equal to n, the n-sized clusters being clustered in frequency.
摘要:
An apparatus and method for cell acquisition and downlink synchronization acquisition in an OFDMA wireless communication system are provided. In an SS apparatus in a broadband wireless communication system, a preamble subcarrier acquirer extracts subcarrier values having a preamble code from an FFT signal. A multiplier code-demodulates the subcarrier values by multiplying the subcarrier values by a preamble code. A correlator calculates a plurality of differential correlations in the code-demodulated signal. An IFFT processor IFFT-processes the differential correlations by mapping the differential correlations to subcarriers. A maximum value detector detects a maximum value from the IFFT signal and calculates a timing offset using an IFFT output index having the maximum value.