Modal adaptive antenna using pilot signal in CDMA mobile communication system and related signal receiving method
View Patent ↗One or more input signals are used to generate a Pseudo noise generator and re-inject the signal to obtain a more efficient method of control of a receiver using adaptive antenna array technology. The antenna array automatically adjusts its direction to the optimum using information obtained from the input signal by the receiving antenna elements. The input signals may be stored in memory for retrieval, comparison and then used to optimize reception. The difference between the outputs of the memorized signals and the reference signal is used as an error signal.
1. A modal antenna system, comprising:
a modal antenna, and a memory-enhanced spatial filter for use with the modal antenna;
said modal antenna comprising:
an antenna radiator disposed above a circuit board forming an antenna volume therebetween;
a first frequency tuning parasitic element connected to said circuit board and positioned between the circuit board and the antenna radiator within the antenna volume, and
a second beam steering parasitic element positioned outside of the antenna volume and adjacent to the antenna radiator;
said memory-enhanced spatial filter for use with the modal antenna comprising:
an adaptive processor adapted to receive a plurality of input radio signals and deliver weighted signals therefrom;
a plurality of memory modules each being adapted to store one of said input radio signals;
a plurality of signal combiners, each of said signal combiners being connected to one of said memory modules and further connected to said adaptive processor, the signal combiners each being adapted to combine the corresponding input radio signal from the connected one of said memory modules with the weighted signal from said adaptive processor to form an output signal, the signal combiners collectively forming a plurality of output signals; and
a summing circuit connected to each of said signal combiners and adapted to sum each of the output signals from said signal combiners to form an enhanced signal, the summing circuit being further adapted to resample the enhanced signal through said adaptive processor for actively reconfiguring the enhanced signal and adjusting said weight signals;
wherein a bank of said input radio signals is stored in said memory and used for enhanced signal processing for use with a single modal antenna.
2. The modal antenna system of claim 1 , said memory-enhanced spatial filter further comprising:
a code generator adapted to generate a pseudo noise code detected by a pilot signal;
a noise signal combiner connected to the code generator and the summing circuit and adapted to combine the enhanced signal and said pseudo noise code to form a despread signal;
a filter connected to the noise signal combiner and adapted to filter the despread signal;
a limiter adapted to adjust an amplitude of the filtered despread signal; and
a multiplier adapted to multiply the pseudo noise code and the filtered despread signal to form a reference signal;
wherein said adaptive processor is adapted to determine an error signal by taking a difference of the input radio signals and the reference signal, and said error signal is used to determine optimal weight signals for production by said adaptive processor.
3. The modal antenna system of claim 2 , said memory-enhanced spatial filter further comprising a memory storage device connected to said filter and adapted to store said filtered despread signal for recycling.
4. The modal antenna system of claim 2 , said memory-enhanced spatial filter further comprising an input diversity signal combiner connected to said adaptive processor and said summing circuit, said input diversity signal combiner adapted to provide an additional reference for control of the adaptive processor.