摘要:
A spread spectrum digital communication receiver, of the type comprising an input memory buffer (16) for storing samples of an input signal (y(k)) and a code generator circuit (30) for generating a re-generated user code, incorporates a device (24) for the estimation of a channel delay profile comprises: a basic correlator (32) having a first input (41) for sequentially reading from a memory location of the input memory buffer (16) a plurality of samples of the input signal (y(k)), a second input (43) for receiving from the code generator circuit (30) a re-generated user code, and an output terminal for generating, by means of a correlation operation between the plurality of samples of the input signal and the regenerated user code, a first value of the channel delay profile energy (DP(1)); and a memory controller circuit (36) for addressing said the memory buffer (16) so that the first input (41) of the basic correlator (32) is successively fed with the content of several memory locations of the memory buffer (16), each addressing operation corresponding to a new correlation operation of the basic correlator (32) for the computation of a new value of the channel delay profile energy (DP(l)).
摘要:
A spread spectrum digital communication receiver, of the type comprising an input memory buffer (16) for storing samples of an input signal (y(k)) and a code generator circuit (30) for generating a re-generated user code, incorporates a device (24) for the estimation of a channel delay profile comprises: a basic correlator (32) having a first input (41) for sequentially reading from a memory location of the input memory buffer (16) a plurality of samples of the input signal (y(k)), a second input (43) for receiving from the code generator circuit (30) a re-generated user code, and an output terminal for generating, by means of a correlation operation between the plurality of samples of the input signal and the regenerated user code, a first value of the channel delay profile energy (DP(1)); and a memory controller circuit (36) for addressing said the memory buffer (16) so that the first input (41) of the basic correlator (32) is successively fed with the content of several memory locations of the memory buffer (16), each addressing operation corresponding to a new correlation operation of the basic correlator (32) for the computation of a new value of the channel delay profile energy (DP(l)).
摘要:
A system for estimating the transfer function of a transmission channel such as the downlink channel in a CDMA system over which a pilot signal (P-CPICH) and a data signal (DPCH) are transmitted. The system includes: - at least one estimator (21, 22, 27; 24, 23, 25) for producing first and second channel estimates from the pilot signal and the data signals, and - a combination node (26) for combining the first and second channel estimates to obtain final combined channel estimates. The system includes an interpolator module (25) adapted for interpolating the second channel estimates over a basic estimation reference time (T) to produce equal numbers of channel estimates over the basic estimation reference time (T) derived from the data signal and the pilot signal respectively, and, possibly - rate adaptation modules (23, 27) adapted for mapping the channel estimates on the basic estimation reference time (T). The combination node is a summation node (26) producing the final combined channel estimates as a sum (26) of the first channel estimates and the interpolated second channel estimates.