Adaptive path selection threshold setting for DS-CDMA receivers

DETAILED DESCRIPTION In the following description, for purposes of explanation and not limitation, specific details are set forth, such as particular circuits, circuit components, techniques, etc.
in order to provide a thorough understanding of the present invention.
However, it will be apparent to one skilled in the art that the present invention may be practiced in other embodiments that depart from these specific details.
In other instances, detailed descriptions of well-known methods, devices, and circuits are omitted so as not to obscure the description of the present invention.
FIG.
2 shows a block diagram of an exemplary searching and tracking unit 100 in which the present invention can be implemented.
Note that this particular configuration illustrated in FIG.
2, e.
g.
, the number of antenna signals and sectors, is purely exemplary.
Sector 1.
sub.
1 through sector 1.
sub.
6, represent different antenna sectors associated with the receiver.
The composite DS-CDMA signals received on sectors 1.
sub.
1 through 1.
sub.
6 are initially processed by searching and tracking unit 100 at selector unit 3.
Selector unit 3 contains a pilot demultiplexer and a buffer, (not shown), for each antenna signal.
The demultiplexers extract pilot symbols and other samples from the data stream.
The demultiplexed and buffered signals are selectively distributed to searchers 5.
sub.
1 through 5.
sub.
L.
The searchers 5.
sub.
1 through 5.
sub.
L perform complex correlations using appropriate codes (e.
g.
, short and long Gold codes) on the demultiplexer/buffered signals passed from the selector unit 3 to "search" for a desired signal in the composite signal received on active ones of antenna sectors 1.
sub.
1 -1.
sub.
6.
These correlations are performed over a given time or search window.
As a result, searchers 5.
sub.
1 through 5.
sub.
L deliver a DPP for each antenna signal to the path selection unit 7.
Although the details of DPP calculation are not particularly relevant to this description, the interested reader is referred to German Application Number DE-19824218