Yihong Qi
Yihong Qi, Sunnyvale, CA US
Patent application number | Description | Published |
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20100067618 | D-PSK Demodulation Based On Correlation Angle Distribution - An apparatus and method is described that provides optimal D-PSK demodulation based on the distribution of phase differences between successive D-PSK symbols. A plurality of D-PSK data symbols are received, and each symbol is characterized by a real component and an imaginary component. An angle of correlation between any two successive symbols is calculated. A variance of correlation angles is obtained by using data symbols or pilot symbols, if available. The probability of the correlation angle being each of possible phase difference according the D-PSK constellation is then determined. From the probabilities of the particular correlation angle, a probability of each input bit being a “0” or “1” is determined. | 03-18-2010 |
20100303156 | Method and Apparatus for Providing Precise Transport Stream Packet Ordering and Erasure Optimization for Digital Video Decoder - One method includes estimating, by a lost packet determination logic, an expected number of packets, expected to be received within a time interval, based on packet arrival speed; and determining a number of lost packets by using the expected number of packets and a packet counter wherein the packet counter counts a plurality of received packets. The method may further include comparing the expected number of packets to the packet counter and determining that the expected number of packets is greater than the packet counter; and then using the expected number of packets and the packet counter to determine the actual number of lost packets, where the actual number of lost packets exceeds the packet counter maximum. The methods may also introduce erasures when there is uncertainty of whether some packets or bytes are in error, such that a simplified erasure-based Reed-Solomon decoder may be used. | 12-02-2010 |
Yihong Qi, Schaumburg, IL US
Patent application number | Description | Published |
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20090067549 | Optimal Two-Layer Coherent Demodulation for DPSK (Differential Phase Shift Keying) - A D-PSK demodulator utilizes a two-layer coherent approach to estimate the phase shift of adjacent symbols. There is generated a probability set of each received symbol being one of possible constellation values. There is also generated a probability set of each of possible phase difference between two adjacent symbols. This probability set is then converted into soft bit information according to specific mathematical operation. | 03-12-2009 |
20090304113 | Optimal Blind Channel Estimation for DQPSK Demodulation - An apparatus and method are described that provide an optimal blind channel estimation approach for a differential quadrature phase shift keying (DQPSK) modulation communication receiving system. The described blind channel estimation technique takes advantage of the characteristics of DQPSK constellations and the fact that estimates of relative channel phase distortion, and not absolute channel phase distortion, are sufficient for a DQPSK demodulation scheme. The described channel estimation approach provides low complexity, offers improved demodulation performance, and is theoretically optimal. It is particularly useful in existing DQPSK-based communications protocols that do not provide sufficient reference symbols for channel estimation. | 12-10-2009 |
20100002783 | Blind Channel Estimation for PSK and D-PSK Modulated Multicarrier Communication Systems - An apparatus and method is described that provide an efficient blind channel estimation approach for PSK and DPSK modulated multicarrier communication systems. With the requirement that the channel phase difference between any two adjacent carriers is smaller than one half of the minimum phase difference between two symbols of the PSK or DPSK constellation, a low-complexity deterministic approach to channel estimation is devised. This approach is highly effective, robust, and particularly useful for time varying channels with low AWGN noise. | 01-07-2010 |
Yihong Qi, Tokyo JP
Patent application number | Description | Published |
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20090207885 | Delay estimation apparatus and method - Delay estimation apparatus and method, comprising: a correlation step which a correlation function between a received signal and a supplied template waveform is generated, AD conversion step at which said correlation output generated at said correlation step is uniformly sampled into discrete samples; and arithmetic operation step at which a time delay estimate of the received signal based on said discrete samples generated at said AD conversion step is computed, wherein a selection criterion depending on the digital sampling frequency used at said AD conversion means is checked, if said selection criterion is satisfied, computes the time delay estimate based on the direct pick method, and if said selection criterion does not hold, computes the time delay estimate based on the simplified maximum likelihood (ML) method. | 08-20-2009 |
20090296783 | Delay estimation apparatus and method - The delay estimation apparatus ( | 12-03-2009 |
20090296831 | Wireless Communication Method and System - Wireless communication method for wireless communication from transmitter to receiver, comprising: | 12-03-2009 |
20090323771 | Interactive Wireless Communication Device - One communication apparatus | 12-31-2009 |
Yihong Qi, Shenzhen CN
Patent application number | Description | Published |
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20150280844 | METHOD AND DEVICE FOR TESTING PERFORMANCE OF WIRELESS TERMINAL - A method and a device for testing a performance of a wireless terminal and a computer readable storage medium are provided. The wireless terminal is placed in a first anechoic chamber and comprises m antennas, where m is a positive integer greater than 1. The method comprises steps of: S | 10-01-2015 |