公开(公告)号：CA2600489A1

公开(公告)日：2006-09-21

申请号：CA2600489

申请日：2006-03-13

Applicant: QUALCOMM INC

Inventor： LING FUYUN ,  MURTHY VINAY ,  GUPTA ALOK ,  CHUNG SEONG TAEK

IPC: H03J7/04

Abstract: Techniques for performing frequency control in an OFDM system are described. In one aspect, frequency acquisition is performed based on a received pilot, and frequency tracking is performed based on received OFDM symbols. For frequency acquisition, an initial frequency error estimate may be derived based on the received pilot, and an automatic frequency control (AFC) loop may be initialized with the initial frequency error estimate. For frequency tracking, a frequency error estimate may be derived for each received OFDM symbol, and the AFC loop may be updated with the frequency error estimate. Frequency error in input samples is corrected by the AFC loop with the initial frequency error estimate as well as the frequency error estimate for each received OFDM symbol. In another aspect, a variable number of samples of a received OFDM symbol are selected, e.g., based on the received OFDM symbol timing, for use for frequency error estimation.

公开(公告)号：DE60022750T2

公开(公告)日：2006-07-06

申请号：DE60022750

申请日：2000-05-10

Applicant: QUALCOMM INC

Inventor： LING FUYUN

IPC: H04B1/7085 ,  H04L25/02 ,  H04B1/7115 ,  H04B7/005 ,  H04Q7/38

Abstract: Apparatus for a transmitter and a receiver which enhance the performance of a system coherent demodulation by utilizing non-pilot sub-channels to enhance the accuracy of estimates of amplitude and phase noise inherent in the transmission channel is described. This enhancement is accomplished by utilizing the corrected received data on a fundamental channel to enhance a pilot channel estimate, which is subsequently utilized by a dot product module in demodulating a supplementary data channel.

公开(公告)号：CA2575528A1

公开(公告)日：2006-02-09

申请号：CA2575528

申请日：2005-07-29

Applicant: QUALCOMM INC

Inventor： MURALI RAMASWAMY ,  VIJAYAN RAJIV ,  LING FUYUN ,  WANG MICHAEL MAO

IPC: H04L1/00

Abstract: A method for improving frequency diversity in an OFDM system using interleaved interlaces for constellation symbol interleaving comprises interleaving a number of subcarriers of an interlace in a bit reversal fashion and interleaving a number of interlaces in the bit reversal fashion.

公开(公告)号：AU2005267808A1

公开(公告)日：2006-02-09

申请号：AU2005267808

申请日：2005-07-29

Applicant: QUALCOMM INC

Inventor： WANG MICHAEL MAO ,  LING FUYUN ,  VIJAYAN RAJIV ,  MURALI RAMASWAMY

IPC: H04L1/00

Abstract: A method for improving frequency diversity in an OFDM system using interleaved interlaces for constellation symbol interleaving comprises interleaving a number of subcarriers of an interlace in a bit reversal fashion and interleaving a number of interlaces in the bit reversal fashion.

公开(公告)号：DE60022750D1

公开(公告)日：2006-02-02

申请号：DE60022750

申请日：2000-05-10

Applicant: QUALCOMM INC

Inventor： LING FUYUN

IPC: H04B1/7085 ,  H04B1/7115 ,  H04B7/005 ,  H04L25/02 ,  H04Q7/38

Abstract: Apparatus for a transmitter and a receiver which enhance the performance of a system coherent demodulation by utilizing non-pilot sub-channels to enhance the accuracy of estimates of amplitude and phase noise inherent in the transmission channel is described. This enhancement is accomplished by utilizing the corrected received data on a fundamental channel to enhance a pilot channel estimate, which is subsequently utilized by a dot product module in demodulating a supplementary data channel.

公开(公告)号：DE60114881D1

公开(公告)日：2005-12-15

申请号：DE60114881

申请日：2001-12-27

Applicant: QUALCOMM INC

Inventor： LING FUYUN ,  CHEN TAO

IPC: H04B7/00 ,  H04B7/005 ,  H04B7/26 ,  H04W52/12 ,  H04W52/14 ,  H04W52/20 ,  H04W52/22 ,  H04W52/42

Abstract: A novel and improved method and apparatus for performing closed loop forward link power control using a selected dedicated and power controlled forward link signal is described. A "Selected Signal Bit Error Rate" (SSBER) is estimated, where each selected signal "bit" consists of a number selected signal chips distributed over a frame. In addition, the method estimates the normalized variance of the signal energy (or C/I) for each packet. The average number of fingers in lock is also used to determine the power control set point.

公开(公告)号：AU2005219932A1

公开(公告)日：2005-09-15

申请号：AU2005219932

申请日：2005-02-25

Applicant: QUALCOMM INC

Inventor： AGRAWAL AVNEESH ,  LING FUYUN ,  KHANDEKAR AAMOD

IPC: H04L25/03 ,  H04L1/00

Abstract: For an iterative channel and interference estimation and decoding scheme, prior information for channel gain and interference is initially obtained based on received pilot symbols. Forward information for code bits corresponding to received data symbols is derived based on the received data symbols and the prior information and then decoded to obtain feedback information for the code bits corresponding to the received data symbols. A posteriori information for channel gain and interference for each received data symbol is derived based on the feedback information for that received data symbol. The a posteriori information for the received data symbols and the prior information are combined to obtain updated information for channel gain and interference for each received data symbol. The process can be repeated for any number of iterations. The prior, a posteriori, and updated information may be represented by joint probability distributions on channel gain and interference. The forward and feedback information may be represented by log-likelihood ratios.

公开(公告)号：AU2005208658A1

公开(公告)日：2005-08-11

申请号：AU2005208658

申请日：2005-01-20

Applicant: QUALCOMM INC

Inventor： LING FUYUN ,  GORE DHANANJAY ASHOK ,  KRISHNANMOORTHI RAGHURAMAN ,  MUKKAVILLI KIRAN ,  MANTRAVADI ASHOK

IPC: H04L25/02 ,  H04L27/26

Abstract: Pilot transmission and channel estimation techniques for an OFDM system with excess delay spread are described. To mitigate the deleterious effects of excess delay spread, time filtering is utilized. Time filtering is utilized to combat excess delay spread effects in channel estimation. The time filtering is performed in the presence of staggered pilots and helps in improving the channel estimate in the presence of excess delay spread.

公开(公告)号：AU2004307128A1

公开(公告)日：2005-05-12

申请号：AU2004307128

申请日：2004-10-22

Applicant: QUALCOMM INC

Inventor： LING FUYUN ,  MANTRAVADI ASHOK ,  MURALI RAMASWAMY ,  WALKER KENT G ,  VIJAYAN RAJIV

IPC: H04L12/18 ,  H04L12/56 ,  H04W74/04 ,  H04W88/08

Abstract: A method of broadcasting data in a wireless broadcast network, comprising multiplexing data for a wide-area transmission onto a first transmission span, the wide-area transmission being sent from a plurality of transmitters in the network; multiplexing data for a local transmission onto a second transmission span, wherein the multiplexing is onto frequency subbands pseudo-randomly selected from among all usable frequency subbands and the local transmission being sent from a subset of the plurality of transmitters; selecting the first and second transmission spans based on an amount of data to broadcast for the wide-area transmission and an amount of data to broadcast for the local transmission; and broadcasting the local and wide-area transmissions via a wireless link, wherein the data for the wide-area transmission and the data for the local transmission are time division multiplexed (TDM) at each base station, and wherein the first and second transmission spans are first and second time segments, respectively, of a frame of a predetermined time duration as well as a corresponding system.

公开(公告)号：HK1068465A1

公开(公告)日：2005-04-29

申请号：HK05100463

申请日：2005-01-18

Applicant: QUALCOMM INC

Inventor： LING FUYUN ,  WALTON JAY R ,  HOWARD STEVEN J ,  WALLACE MARK ,  KETCHUM JOHN W

IPC: H04J99/00 ,  H04B7/04 ,  H04B7/06 ,  H04B7/08 ,  H04L20100101 ,  H04L1/00 ,  H04L27/26

Abstract: Techniques for transmitting data from a transmitter unit to a receiver unit in a multiple-input mutiple-output (MIMO) communication system. In one method, at the receiver unit, a number of signals are received via a number of receive antennas, with the received signal from the transmitter unit. The received signals are processed to derive channel state information (CSI) indicative of characteristics of a number of transmission channels used for data transmission. The CSI is transmitted back to the transmitter unit. At the transmitter unit, the CSI from the receiver unit is received and data for transmission to the receiver units is processed based on the received CSI.