초록 ▼

The present invention provides a search window delay tracking procedure for use in a multipath search processor of a CDMA radio receiver. A channel impulse responses is estimated for a received signal containing plural paths, each path having a corresponding path delay. A search window defines a del

The present invention provides a search window delay tracking procedure for use in a multipath search processor of a CDMA radio receiver. A channel impulse responses is estimated for a received signal containing plural paths, each path having a corresponding path delay. A search window defines a delay profile that contains the plural paths of the received signal. A mean or average delay is calculated for the estimated channel impulse response (CIR), and an error is determined between the mean CIR delay and a desired delay position corresponding to the center of the CIR search window. An adjustment is made to reduce that error so that the center of the search window and the mean CIR delay are aligned. The error may be processed either linearly (in one embodiment) or non-linearly (in another embodiment) to minimize the error and to reduce an influence of noise. A non-linear filtering process includes calculating a delay spread from the mean CIR delay calculated for successive processing cycles of a window delay tracking procedure corresponding to each new input. A difference is determined between the successive delay spreads. Adjustment signal is set equal to the error signal if the difference is less than or equal to a threshold. Alternatively, the adjustment signal is set to zero if the difference is greater than the threshold. Consequently, if the delay spread in the current iteration is significantly different from the delay spread in the previous iteration, the new error sample calculated in the current iteration is considered unreliable, and no adjustment is made.

대표청구항 ▼

1. In a radio receiver, a method comprising the steps of:estimating a channel impulse response for a received signal containing plural paths, each path having a corresponding path delay; calculating a mean delay for the estimated channel impulse response (CIR) using plural path delays; determining a

1. In a radio receiver, a method comprising the steps of:estimating a channel impulse response for a received signal containing plural paths, each path having a corresponding path delay; calculating a mean delay for the estimated channel impulse response (CIR) using plural path delays; determining a delay error between the mean CIR delay and a desired delay position; and making an adjustment to reduce the delay error.