Abstract: A method for inter-carrier interference cancellation is provided. A time-domain received signal is detected to obtain information of an inter-symbol interference free region. Multiple cyclic useful symbols are obtained from the time-domain received signal according to the information of the inter-symbol interference free region and a set of multi-step windowing coefficients is generated. Adjusted cyclic useful symbols are obtained by multiplying the cyclic useful symbols by the set of multi-step windowing coefficients, respectively, and then combined in a time domain to obtain a time-domain combination signal. The inter-carrier interference of each of sub-carriers of the time-domain combination signal is centralized on neighboring D sub-carriers. The time-domain combination signal is transformed into a frequency-domain received signal. The frequency-domain received signal and its corresponding channel response matrix are divided into overlapped signal blocks according to D.

Abstract: A signal receiving method of a receiver includes following steps. Multiple time-domain received signals are transformed into multiple frequency-domain received signals, and channel response matrices corresponding to the frequency-domain received signals are estimated. The frequency-domain received signals are STBC decoded and multiple original combination signals are obtained based on the corresponding channel response matrices. The frequency-domain received signals are rearranged, and the rearranged frequency-domain received signals are STBC decoded and multiple rearrangement combination signals are obtained based on the corresponding channel response matrices. The original combination signals and the rearrangement combination signals are randomly chosen and summed to obtain multiple complex signals. The complex signal with minimum interference power is selected and then the selected signal is used to cancel interference and compensate the channel effect to obtain the detected data.

Abstract: This invention provides a transmission architecture of transmitter which includes a forestage module, a pilot insertion, a scramble selector, and a backstage module. A frequency domain data symbol is transmitted by the forestage module. A pilot signal is inserted in the frequency domain data symbol by the pilot insertion, and a frequency domain pilot symbol is produced. The frequency domain pilot symbol performed a scramble operation and a select operation with certain scramble patterns by the scramble selector, and a requirement symbol is produced. The requirement symbol is converted into the transmitted signal by the backstage module. Because the use of the scramble operation and the select operation from the scramble selector, the transmission architecture of transmitter provided by this invention can both reduce the PAPR and increase the multi-cell diversity gain in an OFDM single frequency network system.

Abstract: A signal receiving method of a receiver includes following steps. Multiple time-domain received signals are transformed into multiple frequency-domain received signals, and channel response matrices corresponding to the frequency-domain received signals are estimated. The frequency-domain received signals are STBC decoded and multiple original combination signals are obtained based on the corresponding channel response matrices. The frequency-domain received signals are rearranged, and the rearranged frequency-domain received signals are STBC decoded and multiple rearrangement combination signals are obtained based on the corresponding channel response matrices. The original combination signals and the rearrangement combination signals are randomly chosen and summed to obtain multiple complex signals. The complex signal with minimum interference power is selected and then the selected signal is used to cancel interference and compensate the channel effect to obtain the detected data.

Abstract: A transmission method of a wireless signal including the following steps is provided. Multiple orthogonal frequency division multiplexing (OFDM) symbols carried by multiple subcarriers are generated according to a data signal. A scrambling pattern including multiple scrambling symbols is generated, wherein the scrambling symbols respectively correspond to the subcarriers in the frequency domain. The scrambling symbols corresponding to two contiguous subcarriers are correlated. The scrambling symbols are utilized to encode the OFDM symbols carried by the corresponding subcarriers.

Abstract: A method for inter-carrier interference cancellation is provided. A time-domain received signal is detected to obtain information of an inter-symbol interference free region. Multiple cyclic useful symbols are obtained from the time-domain received signal according to the information of the inter-symbol interference free region and a set of multi-step windowing coefficients is generated. Adjusted cyclic useful symbols are obtained by multiplying the cyclic useful symbols by the set of multi-step windowing coefficients, respectively, and then combined in a time domain to obtain a time-domain combination signal. The inter-carrier interference of each of sub-carriers of the time-domain combination signal is centralized on neighboring D sub-carriers. The time-domain combination signal is transformed into a frequency-domain received signal. The frequency-domain received signal and its corresponding channel response matrix are divided into overlapped signal blocks according to D.

Abstract: A device for signal synchronization in a communication system is configured to perform a first sliding correlation for a received signal and a pseudo-random noise (PN) sequence to obtain information on symbol timing, identify a fractional carrier frequency offset (FCFO) using the information on symbol timing and the cyclic extension property of the PN guard interval (GI), and provide a first product by multiplying the received signal with the FCFO. The device is also configured to provide a set of second products by multiplying the first product with each of a set of phases related to integral carrier frequency offsets (ICFOs), perform a second sliding correlation for the PN sequence and each one of the set of the second products to thereby provide a set of peak values, and identify an ICFO by detecting an index number of a maximal value among the set of peak values.

Abstract: An apparatus capable of inter-carrier interference (ICI) cancellation in a communication system, the apparatus comprising a detecting module configured to detect an ISI-free region free from inter-symbol interference (ISI) in a guard interval (GI) of a symbol in time domain, a windowing module configured to provide a windowing function in time domain, identifying a weight value in the windowing function based on the ISI-free region, and multiplying a channel response related to the symbol by the windowing function in time domain to obtain a windowing result, wherein the windowing result comprises a first portion corresponding to the ISI-free region and a second region corresponding to an end portion of the symbol, the end portion and the ISI-free region having the same length, and a combination module configured to combine the first portion and the second portion of the windowing result in time domain.

Abstract: A method for ICI self-cancellation and ICI reconstruction and cancellation is introduced. The method includes receiving input signals; receiving boundary information regarding a length q of an ISI-free region of the received signals; selecting a plurality of ISI-free signals from the received signals; combining the plurality of ISI-free signals to provide combined signals z(n); performing FFT operations on the combined signals to provide output signals Z(k); reconstructing ICI based on the output signals Z(k) and the length q of the ISI-free region of the input signals r(n) in order to provide an estimated ICI; subtracting the estimated ICI from the output signals Z(k) to provide a cancelled signal W(k); performing a channel estimation for the cancelled signal W(k); equalizing the cancelled signal W(k) to provide an equalized signal; and de-mapping the equalized signal to provide a de-mapped signal d(k).

Abstract: A transmission method of a wireless signal including the following steps is provided. Multiple orthogonal frequency division multiplexing (OFDM) symbols carried by multiple subcarriers are generated according to a data signal. A scrambling pattern including multiple scrambling symbols is generated, wherein the scrambling symbols respectively correspond to the subcarriers in the frequency domain. The scrambling symbols corresponding to two contiguous subcarriers are correlated. The scrambling symbols are utilized to encode the OFDM symbols carried by the corresponding subcarriers.

Abstract: This invention provides a transmission architecture of transmitter which includes a forestage module, a pilot insertion, a scramble selector, and a backstage module. A frequency domain data symbol is transmitted by the forestage module. A pilot signal is inserted in the frequency domain data symbol by the pilot insertion, and a frequency domain pilot symbol is produced. The frequency domain pilot symbol performed a scramble operation and a select operation with certain scramble patterns by the scramble selector, and a requirement symbol is produced. The requirement symbol is converted into the transmitted signal by the backstage module. Because the use of the scramble operation and the select operation from the scramble selector, the transmission architecture of transmitter provided by this invention can both reduce the PAPR and increase the multi-cell diversity gain in an OFDM single frequency network system.

Abstract: A device for signal synchronization in a communication system, the device comprising a first detector configured to perform a first sliding correlation for a received signal and a pseudo-random noise (PN) sequence to obtain information on symbol timing, a second detector configured to identify a fractional carrier frequency offset (FCFO) using the information on symbol timing and the cyclic extension property of the PN guard interval (GI), a first multiplier configured to provide a first product by multiplying the received signal with the FCFO, and a third detector comprising a set of second multipliers configured to provide a set of second products by multiplying the first product with each of a set of phases related to integral carrier frequency offsets (ICFOs), a set of sliding correlators each being configured to perform a second sliding correlation for the PN sequence and one of the set of the second products, the set of sliding correlators providing a set of peak values, and a peak detector configured t

Abstract: An apparatus capable of inter-carrier interference (ICI) cancellation in a communication system, the apparatus comprising a detecting module configured to detect an ISI-free region free from inter-symbol interference (ISI) in a guard interval (GI) of a symbol in time domain, a windowing module configured to provide a windowing function in time domain, identifying a weight value in the windowing function based on the ISI-free region, and multiplying a channel response related to the symbol by the windowing function in time domain to obtain a windowing result, wherein the windowing result comprises a first portion corresponding to the ISI-free region and a second region corresponding to an end portion of the symbol, the end portion and the ISI-free region having the same length, and a combination module configured to combine the first portion and the second portion of the windowing result in time domain.

Abstract: A method for ICI self-cancellation and ICI reconstruction and cancellation is introduced. The method includes receiving input signals; receiving boundary information regarding a length q of an ISI-free region of the received signals; selecting a plurality of ISI-free signals from the received signals; combining the plurality of ISI-free signals to provide combined signals z(n); performing FFT operations on the combined signals to provide output signals Z(k); reconstructing ICI based on the output signals Z(k) and the length q of the ISI-free region of the input signals r(n) in order to provide an estimated ICI; subtracting the estimated ICI from the output signals Z(k) to provide a cancelled signal W(k); performing a channel estimation for the cancelled signal W(k); equalizing the cancelled signal W(k) to provide an equalized signal; and de-mapping the equalized signal to provide a de-mapped signal d(k).

Abstract: A method and apparatus for the signal synchronization of an orthogonal frequency division multiplexing system includes a delay conjugate multiplication module, a phase processor and an edge detector. It provides estimates for the boundaries of inter-symbol interference free region by utilizing the characteristics of a guard interval in combination with the techniques of the delay conjugate multiplication module, phase differential operation, symbol-by-symbol average operation, and edge detection. The method determines a fixed optimal threshold for directly separating the inter-symbol interference region in a mobile environment to obtain an inter-symbol interference free version of symbol information.

Abstract: A method and apparatus for the signal synchronization of an OFDM system are proposed including a delay conjugate multiplication module, a phase processor and an edge detector. It provides estimates for the boundaries of ISI-free region by utilizing the characteristics of the guard interval and combining the techniques of the delay conjugate multiplication module, phase differential operation, symbol-by-symbol average operation, and edge detection. This method provides an improved performance in a multi-path fading channel with large delay spread, and can be utilized in a broadcasting system, such as the DAB and DVB-T systems. This invention is easy to determine a fixed optimal threshold that can directly separate the ISI region in any mobile environment, thereby most symbol information with ISI-free version can be obtained.

Abstract: A synchronization system for an input signal having a plurality of OFDM symbols, each symbol having at least one guard interval, includes a correlation device for providing a product of the input signal with a complex conjugate of the input signal delayed for a predetermined period, an arithmetic device for obtaining an argument value of the product, and a detection device for detecting a transition in phase values of an output of the arithmetic device, wherein the transition occurring when the phase value in one portion of the symbol duration is substantially smaller than another portion of the symbol duration. The system additionally includes a power estimator for detecting an OFDM symbol frame of the input signal with reference to a predetermined threshold, and a device for estimating fractional carrier frequency offset.