Patent ID: 8253622

Claim:
A device for improved directional estimation and/or decoding by means of secondary radar signals, which comprises: at least one array (A) comprising M antenna elements (AE); a low noise linear amplifier (LNA) and first bandpass filter (F 1 ) combination connected to a plug-in connector (S) of the respective antenna elements (AE) in the array; a first linear amplifier (V 1 ) being connected at a filter output of said combination for amplifying the band-limited signal; a mixer (M) connected to the first linear amplifier (V 1 ) for the frequency conversion into a ZF region; a second linear amplifier (V 2 ) and second bandpass filter (F 2 ) combination connected to the mixer output for amplifying and limiting the bandwidth of the signal in the ZF region; a first analog-to-digital converter (AD 1 ) connected to the second bandpass filter (F 2 ) for scanning and quantifying the filter output signal; a configurable signal processor (FPGA) connected to the first analog-to-digital converter (AD 1 ), said processor being connected to a PLL-VCO circuit for controlling the mixer frequency and receiving data for processing; and a processing unit (CPU) connected to the configurable signal processors (FPGA), said unit collecting the data (DD) from all antenna elements (AE) and carrying out the directional estimation by means of a method based on a subspace in which the various gains, phase differences and coupling of antenna elements in the analog input devices connected to the M antenna elements (AE) are taken into account both in estimating the direction and in the detection of received radio data.