公开(公告)号：DE60027270T2

公开(公告)日：2007-04-12

申请号：DE60027270

申请日：2000-02-08

Applicant: QUALCOMM INC

Inventor： LEVIN A ,  RIDDLE C ,  SHERMAN TOM

IPC: H04B1/7085

Abstract: In order to time track an incoming signal, a receiver demodulates a first instance of a signal to produce a first set of energy values corresponding to a set of possible data values of the signal. The receiver also demodulates a second instance of the signal to produce a second set of energy values corresponding to the set of possible data values. The receiver combines the first and the second sets of energy values to determine a combined set of energy values. The receiver determines a first estimate of a most likely transmitted data value based upon the combined set of energy values. The receiver decovers an early set of despread samples of the first instance using a symbol corresponding to the first estimate to produce a first early energy value. The receiver decovers a late set of despread samples of the first instance using the symbol corresponding to the first estimate to produce a first late energy value. Finally, the receiver determines a time offset of the first instance based upon the first early and the first late energy values.

公开(公告)号：DE69918313T2

公开(公告)日：2005-09-29

申请号：DE69918313

申请日：1999-08-13

Applicant: QUALCOMM INC

Inventor： RIDDLE C ,  LEVIN A

IPC: H03M7/24 ,  G06F7/48 ,  H03M7/34 ,  H03M7/00 ,  H03M3/02

Abstract: A method and apparatus for compressing fixed point signals without introducing a bias. Signals are compressed according to a dithered rounding approach wherein signal values are rounded up and rounded down with approximately equal probability, canceling the bias that would otherwise result from the rounding operation. Numerical properties of the input signal are exploited in order to determine whether the signal value should be rounded up or down. Signal compression may, therefore, be introduced at multiple points within a system without accumulating a signal bias and degrading downstream performance. Further, one bit signal compression may be achieved in a particularly efficient fashion with a minimal amount of hardware.

公开(公告)号：DE69928003T2

公开(公告)日：2006-07-27

申请号：DE69928003

申请日：1999-12-09

Applicant: QUALCOMM INC

Inventor： LEVIN A ,  RIDDLE C ,  SHERMAN B

IPC: H04B1/7117 ,  H04B1/7115 ,  H04B1/712 ,  H04B7/26

Abstract: A wireless receiver receiving multipath Wash-code symbols determines which of fingers 402, 410 have locked on a signal. Measurements of the correlation energies between the received signal and all possible symbols are stored in energy storage units 404, 412. The actual signals are combined in combiner 408. A maximum determiner 416 determines the most likely combined symbol, and an index for this symbol is fed back to the energy storage units. Lock detectors 406, 414 use the measurement for this fed-back symbol to determine whether the finger has locked onto a path. This determination is used to decide whether the next signal detected by that finger should be applied to the combiner.

公开(公告)号：DE60027270D1

公开(公告)日：2006-05-24

申请号：DE60027270

申请日：2000-02-08

Applicant: QUALCOMM INC

Inventor： LEVIN A ,  RIDDLE C ,  SHERMAN TOM

IPC: H04B1/7085

Abstract: In order to time track an incoming signal, a receiver demodulates a first instance of a signal to produce a first set of energy values corresponding to a set of possible data values of the signal. The receiver also demodulates a second instance of the signal to produce a second set of energy values corresponding to the set of possible data values. The receiver combines the first and the second sets of energy values to determine a combined set of energy values. The receiver determines a first estimate of a most likely transmitted data value based upon the combined set of energy values. The receiver decovers an early set of despread samples of the first instance using a symbol corresponding to the first estimate to produce a first early energy value. The receiver decovers a late set of despread samples of the first instance using the symbol corresponding to the first estimate to produce a first late energy value. Finally, the receiver determines a time offset of the first instance based upon the first early and the first late energy values.

公开(公告)号：DE69928003D1

公开(公告)日：2005-12-01

申请号：DE69928003

申请日：1999-12-09

Applicant: QUALCOMM INC

Inventor： LEVIN A ,  RIDDLE C ,  SHERMAN B

IPC: H04B1/7117 ,  H04B1/7115 ,  H04B1/712 ,  H04B7/26 ,  H04B1/707

Abstract: A wireless receiver receiving multipath Wash-code symbols determines which of fingers 402, 410 have locked on a signal. Measurements of the correlation energies between the received signal and all possible symbols are stored in energy storage units 404, 412. The actual signals are combined in combiner 408. A maximum determiner 416 determines the most likely combined symbol, and an index for this symbol is fed back to the energy storage units. Lock detectors 406, 414 use the measurement for this fed-back symbol to determine whether the finger has locked onto a path. This determination is used to decide whether the next signal detected by that finger should be applied to the combiner.

公开(公告)号：DE69918313D1

公开(公告)日：2004-07-29

申请号：DE69918313

申请日：1999-08-13

Applicant: QUALCOMM INC

Inventor： RIDDLE C ,  LEVIN A

IPC: H03M7/24 ,  G06F7/48 ,  H03M7/34 ,  H03M7/00 ,  H03M3/02

Abstract: A method and apparatus for compressing fixed point signals without introducing a bias. Signals are compressed according to a dithered rounding approach wherein signal values are rounded up and rounded down with approximately equal probability, canceling the bias that would otherwise result from the rounding operation. Numerical properties of the input signal are exploited in order to determine whether the signal value should be rounded up or down. Signal compression may, therefore, be introduced at multiple points within a system without accumulating a signal bias and degrading downstream performance. Further, one bit signal compression may be achieved in a particularly efficient fashion with a minimal amount of hardware.