Transmission diversity apparatus

Details Transmission diversity apparatus Transmission diversity apparatus

1998-06-25

2001-05-01

Hunter, Daniel S (Department: 2749)

Telecommunications

Receiver or analog modulated signal frequency converter

With wave collector

C455S277200, C455S279100, C455S101000, C375S267000

Reexamination Certificate

active

06226508

ABSTRACT:

BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a transmission diversity apparatus.
2. Description of the Related Art
The conventional transmission diversity apparatus is structured as follows:
FIG. 1
is a block diagram showing one example of the conventional diversity apparatus.
Carrier frequency radio signals received from antennas #1 and #2 are converted to base band signals by receiving RF sections
1
and
2
. Level detectors
3
and
4
detect field strength of each base band signal for a fixed period of time, and send the detected value to mean value calculators
5
and
6
, respectively. The mean value calculators
5
and
6
calculate the mean value of the detected values. A corrector
7
obtains an output difference of the mean value calculators
5
and
6
, and adjusts the characteristics of these level detectors
3
and
4
based on the obtained output difference.
A comparator
8
compares the receiving level of the level detector
3
with that of the level detector
4
, determines which receiving level is higher, and outputs the result to a switching device
9
. The switching device
9
switches the transmission antenna in accordance with the output of the comparator
8
.
A transmitting signal is input from a terminal
10
, modulated by a modulator
11
, and converted to a carrier frequency radio signal by a transmitting RF section. Thereafter, the radio signal passes through a receiving/transmitting separator
13
and is transmitted from either one of antennas #1 and #2 switched by the switching device
9
.
Thus, the convention transmission diversity apparatus selects the antenna having the highest signal receiving level from the plurality of antennas, thereby transmitting the signal. As a result, irregularity of the characteristics of the receiving level measuring system is automatically corrected, so that transmission diversity is effectively performed.
The conventional diversity apparatus, however, selects the transmission antenna based on only the levels of the receiving signals. The receiving signals include a desired and an interfering signal. Due to this, even in a case in which the signal level of an interference station is: high, there causes a disadvantage in which such an antenna may be selected as an appropriate transmitting antenna.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a transmission diversity apparatus, which ca perform appropriate transmission diversity by selecting an antenna whose desired signal power becomes the highest even in a case in which an interference station exists.
In order to achieve the above object, there is provided a transmission diversity apparatus comprising a plurality of antennas, each having gain controlling means for controlling receiving signal power; correlation processing means for processing the correlation between an output of the gain controlling means and a reference signal; and standardizing means for standardizing an output of the correlation processing means with a gain control amount of the gain controlling means, the transmission diversity apparatus selecting an antenna, which can obtain an output having a maximum desired signal power among outputs of the standardizing means, as a transmission antenna.


REFERENCES:
patent: 5568523 (1996-10-01), Tsujimoto
patent: 5584057 (1996-12-01), Dent
patent: 5598404 (1997-01-01), Hayashi et al.
patent: 5652764 (1997-07-01), Kanzaki et al.
patent: 5787122 (1998-07-01), Suzuki
patent: 5883921 (1999-03-01), Andren et al.
patent: 5-29990 (1993-02-01), None
patent: 8-32498 (1996-02-01), None
patent: 9-18396 (1997-01-01), None
English Language Abstract of JP No. 5-299990.
English Language Abstract of JP No. 8-32498.
English Language Abstract of JP No. 9-18396.

Affiliated with

Also associated with

Rating

Transmission diversity apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Transmission diversity apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Transmission diversity apparatus will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2443294