Abstract:
A method for a mobile station to provide to a base station feedback of channel state information (CSI) regarding a plurality of communication channels between the mobile station and the base station. The method includes: estimating the CSI by calculating a plurality of channel responses each for one of the communication channels; compressing the estimated CSI; and sending the compressed CSI as the feedback to the base station.
Abstract:
A method for a mobile station to provide to a base station feedback of channel state information (CSI) regarding a plurality of communication channels between the mobile station and the base station. The method includes: estimating the CSI by calculating a plurality of channel responses each for one of the communication channels; compressing the estimated CSI; and sending the compressed CSI as the feedback to the base station.
Abstract:
A subcarrier allocation method for use by a transmitter, the transmitter being configured to, when transmitting first and second data streams, allocate pilot symbols for the first and second data streams to subcarriers, such that a first plurality of subcarriers carry the pilot symbols for the first data stream and a second plurality of subcarriers carry the pilot symbols for the second data stream. The method includes allocating, when the transmitter transmits the first data stream but does not transmit the second data stream, the second plurality of subcarriers to carry no formation or information relating to the first data stream.
Abstract:
A wireless communication method implemented in a communication system may include receiving a data sequence to be permuted, and obtaining information associated with the data sequence to be permuted, the information containing at least a length of the data sequence and a sampling spacing for permuting the data sequence. The method may also include identifying a first portion of the data sequence having a first number of adjacent data items, and a second portion of the data sequence having a second number of adjacent data items. The method may also include accessing the first number of data items from the first portion at the sampling spacing, and placing the accessed first number of data items into a predetermined number of sub-blocks included within a permuted data sequence to be generated based on the received data sequence. The method may further include inserting each of the second number of data items into an end position of one of the sub-blocks within the permuted data sequence, and outputting the permuted data sequence.
Abstract:
A method and OFDM receiver for estimating timing offset are provided. The method includes receiving OFDM data to calculate frequency offset between a transmitter carrier frequency and a receiver carrier frequency, determining first timing offset based on the frequency offset, compensating the OFDM data with the first timing offset, estimating a residual common phase based on the compensated OFDM data, determining second timing offset based on the residual common phase, and compensating the OFDM data with the second timing offset, if the frame symbol index exceeds the predetermined data length.
Abstract:
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.
Abstract:
A DC offset estimation system is disclosed. A DC offset estimation system includes a carrier frequency offset estimator receiving an input signal and estimating a carrier frequency offset value, a symbol timing recovery unit providing a symbol boundary of the input signal, and a DC offset estimator estimating a DC offset value to compensate the input signal based on the input signal, the carrier frequency offset value, and the symbol boundary.
Abstract:
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.
Abstract:
A wireless communication method may include receiving a first data stream comprising a data sequence and computing a permutation sequence based on a content of the received first data stream. The permutation sequence is a non-predetermined sequence. The method may further include performing a permutation on the first data stream based on the permutation sequence to generate a permuted first data stream being configured for wireless transmission.
Abstract:
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.