Industrial Technology Research Institute

Ching-Yung Chen

Ming-Chien Tseng

Chorng-Ren Sheu

Chih-Chun Feng

Yung-Hua Hung

Chih-Yang Kao

Yi-Ting Wang

Hsien-Wen Chang

Fang-Chu Chen

Ce-Min Fang

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.

Transmission architecture of transmitter

A method for transmitting signals using orthogonal frequency division multiplexing (OFDM) symbols in a wireless communication system, includes: selecting a plurality of OFDM symbols as a symbol group in time dimension; and multiplying a scrambling pattern with the symbol group.

Method and apparatus for providing time-frequency diversity in OFDM wireless communication systems

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.

Transmission method of wireless signal and transmitter using the same

A shift space-time encoding scheme applies STBC over hierarchical modulation. A low-priority bit stream is modulated to complex symbols using STBC encoding and a high-priority bit stream is modulated to complex symbols without STBC encoding. Complex symbols from the low-priority bit stream together with the complex symbols from the high-priority bit stream are added to form a hierarchical 64-QAM constellation.

Shift space-time coding for digital video broadcasting systems

An apparatus for synchronizing pilots contained in symbols received by a receiver in a multicarrier transmission system and a method thereof are provided. Frequency or Time-frequency correlation-based scheme, with exploitation of time-frequency correlation characteristics of the pilots, may be used for identifying the positions of the pilots in frequency or time and frequency dimensions consisting of received symbols. In one example, the apparatus includes a pilot compensator and a signal selector for determining at least one correlation set, a correlator for generating one correlation set result for each of the correlation set, and a judgment or processing unit for determining positions of the pilots in response to the correlation set result.

Frequency correlation based synchronization for coherent OFDM receiver and apparatus thereof

A system for receiving a digital broadcast includes an input terminal that receives the digital broadcast containing scalable data, and a controller for controlling an operation mode of the system. In addition, the system may also include a processor that decodes the data, and a power management device that varies the amount of data to be decoded according to the operation mode.

Systems and methods of flexible power management applicable to digital broadcasting

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).

Apparatus and method for inter-carrier interference self-cancellation and inter-carrier interference reconstruction and cancellation

A structure and method for demodulating two-level differential amplitude-shift-keying signals using simple adding operations are provided. Threshold values are dynamically adjusted according to the channel response. By comparing the threshold values and the differential amplitude values, it can be found whether the amplitude of the received signal is changed. Furthermore, it no needs to know the changed value of received signal amplitudes and the differential two-level amplitude-shift-keying signals can be demodulated by just detecting whether the amplitude of the received signal is changed. By this idea, the complexity of the receiver implementation is simplified and the demodulator can get better performance.

Communication system with demodulation of two-level differential amplitude-shift-keying signals

A modulation recognition method and device for digitally modulated signals with multi-level magnitudes are provided. The modulation recognition method includes selecting plural quantization sizes used to construct plural statistic histograms related to the magnitude of a sequence of data, setting up an off-line processing to extract plural useful feature patterns for each modulation type of interest, receiving a sequence of samples of a modulated object signal and constructing plural statistic histograms related to the magnitude of these samples, and adopting a hierarchical classification method for modulation recognition. It can be applied to the adaptive-modulation communication system, software defined radio, digital broadcasting systems and military communication systems. It can also be integrated with modulation recognition techniques for other types of modulated signals to function in a universal demodulator. It recognizes digitally modulated signals of multi-level magnitudes with low computational complexity in advancing the efficiency of communication systems.

Growing community of inventors

Hsinchu, Taiwan

Ching-Yung Chen