Appeal No. 2002-2291
Application No. 09/196,117
The invention is directed to estimating the direction of arrival (DOA) in an antenna
diversity system. It is alleged that in order to estimate the DOA of a signal, signals received by
each antenna beam must be received separately by corresponding radio receiver branches and that
there are no known systems which can employ antenna diversity and provide an accurate
estimation of DOA. Giving the example of the primary applied reference to Reudink, it is said
that Reudink discloses a system which employs angular diversity in which branches from each
antenna beam are distributed in two groups and that the two groups of signals are delayed in
relation to each other and then combined. It is alleged that such combining of these signals loses
the angular information and, therefore, DOA estimation is impossible.
According to the instant invention, by introducing an artificial time delay into antenna
elements with respect to other antenna elements covering a corresponding space area prior to
combining the signals, this allows for DOA estimation while being able to take advantage of the
benefits of antenna diversity.
Representative independent claim 1 is reproduced as follows:
1. A receiver system comprising,
at least two antenna assemblies each providing a set of antenna beams and for each beam
in a first of said sets of antenna beams there is a corresponding beam in the second of said sets of
antenna beams covering a corresponding space area,
delay elements connected to outputs of at least one of said antenna assemblies;
combiner devices, each with inputs connected, either directly or via said delay elements,
to outputs of said antenna assemblies, said combiner devices each combining received signals
derived from corresponding beams; and
2
Page: Previous 1 2 3 4 5 6 7 8 9 10 Next
Last modified: November 3, 2007