Memory based devcie and method for channel estimation in a digital communication receiver

A method for the estimation of the channel delay profile energy in 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, comprising the steps of:

• a) sequentially reading a first plurality of samples of the input signal y(k) from said memory buffer 16;
• b) correlating said plurality of samples of said input signal with said re-generated user code for generating a first value of the channel delay profile energy (DP(k));
• c) updating the reading position on said input memory buffer (16) for reading a further plurality of samples of the input signal (y(k));
• d) correlating said further plurality of samples of said input signal with said re-generated user code for generating a further value of the channel delay profile energy (DP(k+1)), said generated value of the channel delay profile energy (DP(k+1)) being stored in a profile accumulation memory (34);
• e) repeating the steps c) to d) in order to compute all the values of the channel delay profile.

A spread spectrum digital communication receiver, comprising:

• a code generator circuit (52) for generating a re-generated user code;
• a memory buffer (50) for storing samples of said re-generated user code;
• a device (64) for the estimation of a channel delay profile energy, for computing the time delays and amplitudes of each received multi-path component of an input signal (y(k)) received by said receiver;
• a plurality of fingers (78);
• a finger allocation unit (76) for processing said channel delay profile energy in order to select the strongest multi-path components of said input signal (y(k)) and allocate them to said fingers (78);
• characterized in that said device (64) for the estimation of a channel delay profile energy comprises:
• a basic correlator (54) having a first input (41) for receiving said input signal (y(k)) and a second input (43) for sequentially reading from a memory location of said memory buffer (50) a plurality of samples of said re-generated user code, and an output terminal for generating, by means of a correlation operation between said input signal and said plurality of samples of said regenerated user code, a value of said channel delay profile energy (DP(1));
• a memory controller circuit (58) for addressing said memory buffer (50) so that said second input (43) of said basic correlator (54) is successively fed with the content of the memory locations of said memory buffer (50), each addressing operation corresponding to a new correlation operation of said basic correlator (58) for the computation of a new value of said channel delay profile energy (DP(1)).

A method for the estimation of the channel delay profile energy in a spread spectrum digital communication receiver of the type comprising a code generator circuit (52) for generating a re-generated user code and a memory buffer (50) for storing samples of said re-generated user code, comprising the steps of:

• a) sequentially reading a first plurality of samples of the re-generated user code from said memory buffer (50);
• b) correlating said plurality of samples of said re-generated user code with an input signal y(k) for generating a first value of the channel delay profile energy (DP(k));
• c) updating the reading position on said input memory buffer (50) for reading a further plurality of samples of the re-generated user code;
• d) correlating said further plurality of samples of said re-generated user code with said input signal y(k) for generating a further value of the channel delay profile energy (DP(k+1)), said generated value of the channel delay profile energy (DP(k+1)) being stored in a profile accumulation memory (56);
• e) repeating the steps c) to d) in order to compute all the values of the channel delay profile.