Adaptive antenna receiver

• US 20040048593A1
• Filed: 06/19/2003
• Published: 03/11/2004
• Est. Priority Date: 12/21/2000
• Status: Active Grant

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Sano, Hiroyasu
• Granted Patent: US 6,879,624 B2
• Time in Patent Office: Days
• US Class Current: 455/323
• CPC Class Codes: H01Q 3/2605 Array of radiating elements provided with a feedback control over the element weights, e.g. adaptive arrays
• CPC Class Codes: H04B 7/0848 Joint weighting

Abstract

A path detector (105) detects multipath waves on a transmission line based on a plurality of despread signals corresponding to fixed directional beams. An adaptive beam forming section (106-1 to 106-L) forms an adaptive beam combined signal for each path, using a weight generated by an adaptive algorithm and the despread signals. An adder (107) combines the adaptive beam signals for all paths, and a data judging section (108) judges data included in the combined signal.

Claims

1. An adaptive antenna receiver comprising:

a beam forming unit that uses a plurality of antennas to forms beams having fixed directivity;

a plurality of despreading units that separately despread a beam signal corresponding to the beams having fixed directivity;

a path detecting unit that detects multipath waves on a transmission line based on the signals obtained by despreding, and outputs path position information as a detection result;

a transmission line estimating unit that estimates a transmission line for transmitting an adaptive beam combined signal for each path, based on the path position information;

a plurality of complex multiplication units each of which separately complex multiplies the despread signals by the transmission line estimation result for each path;

an adaptive beam forming unit that generates a weight for each path by operating an adaptive algorithm for each path, using a plurality of complex multiplication results and data judgment results in each path, and forms an adaptive beam combined signal for each path, using the weight and the despread signals;

a phase matching unit that performs phase matching corresponding to the transmission line estimated by the transmission line estimating unit, using the adaptive beam signal for each path;

a path combining unit that combines the adaptive beam signals after phase matching for all paths; and

a data judging unit that judges the data included in the adaptive beam signals combined.

2. The adaptive antenna receiver according to claim 1, further comprising:

an interference quantity estimating unit that estimates an interference quantity from the adaptive beam combined signal for each path, based on a known sequence added to a transmission slot; and

a normalizing unit that normalizes the adaptive beam signal after phase matching, based on the estimated interference quantity for each path,

wherein the path combining unit combines the adaptive beam signals after phase matching normalization for all paths.

3. The adaptive antenna receiver according to claim 1, wherein

the path detecting unit includes

a plurality of each beam path detecting units each of which uses the signal after despreading for each beam to obtain a path position and a path power value separately;

and

a path selecting section that selects a predetermined number of paths in decreasing order of path power value, from paths having different path positions, and outputs path position information as a selection result, and

each of the each beam path detecting units includes

an in-phase addition unit that in-phase adds all symbols in one slot, by using a known sequence provided for each slot of the despread signal for each beam;

a mean power delay profile unit that performs averaging processing of power over several slots by using the in-phase addition result, to generate a mean power delay profile;

a threshold generating unit that generates a threshold for selecting a path, based on the mean power delay profile; and

a comparison unit that compares the mean power delay profile with the threshold, and outputs a path position of a path exceeding the threshold and the path power value.

4. The adaptive antenna receiver according to claim 1, wherein when the adaptive algorithm is in an initial state, the adaptive beam forming unit sets the weight to 1 with respect to the beam for which a path has been detected, and sets the weight to 0 with respect to other beams.

5. An adaptive antenna receiver comprising:

a beam forming unit that uses a plurality of antennas to form beams having fixed directivity;

a plurality of despreading units that separately despread a beam signal corresponding to the beams having fixed directivity;

a path detecting unit that detects multipath waves on a transmission line based on the signals obtained by despreding, and outputs path position information and predetermined beam selection information necessary for operating the adaptive algorithm as a detection result;

a transmission line estimating unit that estimates the transmission line for transmitting an adaptive beam combined signal for each path, based on the path position information;

a plurality of complex multiplication units each of which separately complex multiplies the despread signal by the transmission line estimation result for each path;

an adaptive beam forming unit that generates a weight common to all paths by operating one adaptive algorithm, using the complex multiplication results, data judgment results, and the beam selection information for all paths, and forms an adaptive beam combined signal for each path, using the weight common to all paths and the despread signals;

a phase matching unit that performs phase matching corresponding to the transmission line estimated by the transmission line estimating unit, using the adaptive beam signal for each path;

a path combining unit that combines the adaptive beam signals after phase matching for all paths; and

a data judging unit that judges the data included in the adaptive beam signals combined.

6. The adaptive antenna receiver according to claim 5, further comprising:

a plurality of adaptive beam forming groups formed of a combination of the transmission line estimating unit, the complex multiplication unit, the adaptive beam forming unit, the phase matching unit, and the path combining unit; and

a group combining unit that combines outputs from the adaptive beam forming groups,

wherein the data judging unit judges the data included in the signal output from the group combining unit.

7. The adaptive antenna receiver according to claim 5, further comprising:

a plurality of adaptive beam forming groups formed of a combination of the transmission line estimating unit, the complex multiplication unit, the adaptive beam forming unit, the phase matching unit, an interference quantity estimating unit that estimates the interference quantity from the adaptive beam combined signal for each path based on a known sequence added to the transmission slot, a normalizing unit that normalizes the adaptive beam signal after phase matching, based on the interference quantity estimated for each path, and

a path combining unit that further combines the outputs from the adaptive beam forming groups,

wherein the data judging unit judges the data included in the signal output from the group combining unit.

8. The adaptive antenna receiver according to claim 5, wherein

the path detecting unit includes

a plurality of each beam path detecting units each of which uses the despread signal for each beam to obtain a path position and a path power value separately;

and

a path selecting section that selects a predetermined number of paths in decreasing order of path power value, from paths having different path positions, and outputs path position information as a selection result, and

each of the each beam path detecting units includes

an in-phase addition unit that in-phase adds all symbols in one slot, by using a known sequence provided for each slot of the despread signal for each beam;

a mean power delay profile unit that performs averaging processing of power over several slots by using the in-phase addition result, to generate a mean power delay profile;

a threshold generating unit that generates a threshold for selecting a path, based on the mean power delay profile;

a comparison unit that compares the mean power delay profile with the threshold, and outputs a path position of a path exceeding the threshold and the path power value; and

a beam selection information generating unit that calculates the sum total of the path power for each beam based on the path position and the path power value, and selects a beam having the largest sum total, to generate beam selection information as a selection result.

9. The adaptive antenna receiver according to claim 5, wherein when the adaptive algorithm is in an initial state, the adaptive beam forming unit sets the weight to 1 with respect to the beam for which a path has been detected, and sets the weight to 0 with respect to other beams.