Industrial Technology Research Institute

Jiun-Yo Lai

Pang-An Ting

Jen-Yuan Hsu

Huei-Jin Lin

Wei Ping Chuang

Lai-Huei Wang

Chin-Hung Chen

Chia-Chi Huang

Chao-Kai Wen

Yu-Tao Hsieh

Jia-Hao Wu

Yung-Yih Jian

Yu T Su

Yen-Shuo Lu

Chao-Wang Huang

Chih-Lun Weng

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.

Progressive parallel interference canceller and method and receiver thereof

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.

Wireless transmission system, receiver thereof, and method for removing inter-carrier interference thereof

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.

Carrier frequency offset estimation method and system

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.

FFT-size detection and cell search for a cellular communication system

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 Gfor each RB of a plurality of RBs; reordering the plurality of RBs based on the G; 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.

Link adaption in wireless communications

The invention provides an FFT-size detection method and system and a cell search method and system based on FFT-size detection, and more particularly to a cell search method based on FFT-size detection in cellular system. The cell search method utilizes two frames to correctly detect the actual cell ID. The cell search method uses the first frame to detect the actual FFT size of a received signal. When the FFT size is determined, the cell search method use the second frame to detect the cell ID of a base station outputting the received signal based on the FFT size.

FFT-size detector and FFT-size detection method and cell search apparatus and cell search method in cellular system

The method disclosed in the invention comprises setting a plurality of subcarrier position hypotheses for a received preamble according to a plurality of ideal subcarrier positions and the maximum amount of integer carrier frequency offset (ICFO), generating a plurality of preamble pattern hypotheses by retrieving the received preamble according to the subcarrier position hypotheses, calculating the correlation between the preamble pattern hypotheses and a plurality of specified preamble patterns, determining to which sector the received preamble belongs according to a correct preamble pattern, the specified preamble pattern having the highest correlation with the preamble pattern hypotheses, obtaining a correct subcarrier position according to the sector to which the received preamble belongs; and estimating the ICFO by calculating the offset between the correct subcarrier position and the subcarrier position hypothesis of the preamble pattern hypothesis having the highest correlation with the correct preamble pattern.

Method and device for estimating integer carrier frequency offset

Fractional carrier frequency offset estimators and related methods are disclosed. The invention may be particularly applied in WiMAX systems. The disclosed method of estimating fractional carrier frequency offset between a transmitter and a receiver includes calculating a first delay correlation based on a first and a second preamble repetitions included in a received signal, processing the phase of the first delay correlation to compensate for a phase rotation of the first delay correlation, and estimating the fractional carrier frequency offset by multiplying a processed phase value, generated after the step of processing the phase of the first delay correlation, by a predetermined value.

Fractional carrier frequency offset estimator and method of estimating fractional carrier frequency offset between transmitter and receiver

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 (P) 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 (L), a first number of pilot signals between a minimum value of L and a maximum number of pilot signals N, wherein the first number of pilot signals Nare equally spaced in time according to the CT data, and equally spaced in frequency. Further, the method includes selecting, when L is less than Land Pis less than a power threshold (P), a second number of pilot signals such that the second number of pilot signals is between the minimum value of L and N, 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 Land Pis greater than P, 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.

Adaptive pilot design for mobile system

A method for compensating IQ imbalance is disclosed. First, an OFDM signal is received. The OFDM signal is translated into frequency domain, wherein the translated OFDM signal has N sub-carriers noted as Y(1)-Y(N). The IQ imbalance compensation factor is generated according to the k-th sub-carrier of the translated signal Y(k), the (N&#x2212;k+2)-th sub-carrier of the translated signal Y(N&#x2212;k+2), and the complex conjugates thereof.

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Taichung, Taiwan

Jiun-Yo Lai