Patent application number | Description | Published |
20080260076 | CARRIER FREQUENCY OFFSET ESTIMATION METHOD AND SYSTEM - 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. | 10-23-2008 |
20080260085 | Method and device for estimating integer carrier frequency offset - 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. | 10-23-2008 |
20080279221 | Method for estimating and compensating IQ imbalance in OFDM systems - 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−k+2)-th sub-carrier of the translated signal Y(N−k+2), and the complex conjugates thereof. | 11-13-2008 |
20080310525 | FFT-size detector and FFT-size detection method and cell search apparatus and cell search method in cellular 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. | 12-18-2008 |
20100008308 | LINK ADAPTION IN WIRELESS COMMUNICATIONS - 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 G | 01-14-2010 |
20100027703 | MULTIPLE-INPUT MULTIPLE-OUTPUT DETECTOR AND DETECTION METHOD USING THE SAME - 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. | 02-04-2010 |
20110013735 | PROGRESSIVE PARALLEL INTERFERENCE CANCELLER AND METHOD AND RECEIVER THEREOF - 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. | 01-20-2011 |
20110164568 | FFT-SIZE DETECTOR AND FFT-SIZE DETECTION METHOD AND CELL SEARCH APPARATUS AND CELL SEARCH METHOD IN CELLULAR 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. | 07-07-2011 |
20130028167 | MULTIPLE-HOP MULTI-INPUT MULTI-OUTPUT AMPLIFY-AND-FORWARD RELAY WIRELESS COMMUNICATION SYSTEM AND METHOD APPLICABLE THERETO - A multiple-hop multi-input multi-output (MIMO) amplify-and-forward relay wireless communication system includes a signal source node, a signal destination node and a plurality of relay nodes, wirelessly coupled between the signal source node and the signal destination node. The relay nodes feed back a plurality of signal to noise ratio information and a plurality of antenna number information to the signal source node. The signal source node allocates a plurality of corresponding transmission powers for the relay nodes and sends to the relay nodes. | 01-31-2013 |