Telecommunications – Transmitter and receiver at same station – Radiotelephone equipment detail
Reexamination Certificate
1999-07-07
2002-10-01
Maung, Nay (Department: 2681)
Telecommunications
Transmitter and receiver at same station
Radiotelephone equipment detail
C455S011100, C455S012100, C455S013100
Reexamination Certificate
active
06459905
ABSTRACT:
TECHNICAL FIELD
This invention is related to a mobile communication system equipped with a portable telephone usable in both a ground system and a satellite system, and a relaying apparatus of this portable telephone.
BACKGROUND ART
Referring now to drawings, a description will be made for a conventional mobile communication system equipped with a portable telephone and a relaying apparatus of this portable telephone.
FIG. 6
is a block diagram for schematically showing, for instance, an arrangement of the conventional portable telephone disclosed in Japanese Unexamined Patent Application No. 8-70262.
In
FIG. 6
, reference numeral
1
shows a ground system antenna/radio frequency unit; reference numeral
2
represents an interface of the ground system antenna/radio frequency unit
1
; reference numeral
3
indicates a satellite system antenna/radio frequency unit; reference numeral
4
denotes an interface of the satellite system/radio frequency unit
3
; reference numeral
5
is a radio control unit; and reference numeral
6
shows an interface for connecting any one of the ground system antenna/radio frequency unit
1
or the satellite system antenna/radio frequency unit
3
with the radio control unit
5
.
FIG. 7
is a block diagram for indicating a detailed arrangement of the ground system antenna/radio frequency unit and of the radio control unit of the conventional portable telephone.
In
FIG. 7
, reference numeral
7
shows an antenna of a ground system, and reference numeral
8
represents a radio frequency unit. Also, reference numeral
9
indicates a receiving IF circuit; reference numeral
10
is a demodulator for demodulating an output signal of the receiving IF circuit
9
; reference numeral
11
shows a baseband processing unit for processing an output signal of the demodulator
10
; reference numeral
12
indicates a modulator for modulating a signal derived from the baseband processing unit
11
; and reference numeral
13
shows a transmitting IF circuit for converting an output signal of the modulator
12
into a transmitting IF signal. Furthermore, reference numeral
14
shows a keyboard connected to the baseband processing unit
11
; reference numeral
15
indicates a display unit for displaying a signal derived from the baseband processing unit
11
; and reference numeral
16
denotes a transmitter/receiver connected to the baseband processing unit.
Furthermore,
FIG. 8
is a block diagram representing, for example, an arrangement of the relaying apparatus of the conventional portable telephone disclosed in Japanese Unexamined Patent Application No. 8-70262.
In
FIG. 8
, reference numeral
17
shows a satellite system antenna/radio frequency unit; reference numeral
18
is a satellite system antenna; reference numeral
19
indicates a radio frequency unit; and reference numeral
20
shows an interface. Also, reference numeral
21
denotes a repeater connected to the satellite system antenna/radio frequency unit
17
; reference numeral
22
indicates an interface; reference numeral
23
represents a frequency converting unit; and reference numeral
24
denotes an interface. Furthermore, reference numeral
25
shows a ground system antenna/radio frequency unit connected to the repeater
21
; reference numeral
26
denotes a ground system antenna; reference numeral
27
represents a radio frequency unit; and reference numeral
28
shows an interface.
Next, a description will now be made of operations of the conventional mobile communication system equipped with the portable telephone and the relaying apparatus thereof. A single portable telephone which may be employed in both a mobile communication system of a ground system and another mobile communication system of a satellite system, namely a so-called “dual mode portable telephone,” is required to be operable in the mobile communication systems in both of the ground system and the satellite system.
Generally specking, in a ground communication system and a satellite communication system, radio interfaces, for instance, transmission/reception frequencies, modulating/demodulating methods, information transfer speeds and the like are different from each other.
As a result, in a dual mode portable telephone, two sets of antennas and radio frequency units are provided which are operable with respect to the ground communication system and the satellite communication system. Also, as indicated in
FIG. 6
, the ground system antenna/radio frequency unit
1
and the satellite system antenna/radio go frequency unit
3
are used in the replacement manner.
In the conventional apparatus of
FIG. 6
, when the portable telephone is used in the ground communication system, the ground system antenna/radio frequency unit
1
is connected to the radio control unit
5
so as to use this portable telephone. When the portable telephone is used in the satellite communication system, the satellite system antenna/radio frequency unit
3
is connected to the radio control unit
5
so as to use this portable telephone.
FIG. 7
is a block diagram for showing a detailed arrangement in the case that the ground system antenna/radio frequency unit
1
is connected to the radio control unit
5
. A reception electromagnetic wave from the ground communication system is received by the antenna
7
, and then is converted into an IF signal by the radio frequency unit
8
.
This IF signal is supplied via the interfaces
2
and
6
and the receiving IF circuit
9
to the demodulator
10
so as to be demodulated. This demodulation signal is converted into a speech signal by the baseband processing unit
11
, and then the speech signal is supplied to the transmitter/receiver
16
.
Conversely, another speech signal entered from the transmitter/receiver
16
is processed by the baseband processing unit
11
, and thereafter the processed speech signal is modulated by the modulator
12
. This modulation signal is converted into a transmitting IF signal by the transmitting IF circuit
13
, and then this transmitting IF signal is supplied via the interfaces
6
and
2
to the radio frequency unit
8
.
In the radio frequency unit
8
, the transmitting IF signal is converted into a transmit signal having a frequency fitted to the radio interface of the ground communication system. Then, this transmit signal is transmitted from the antenna
7
.
In the ground communication system, as the radio frequency, for example, frequencies in a 900 MHz band are employed. The radio frequency unit
8
has a function to convert the frequencies in the 900 MHz band into IF frequencies.
On the other hand, in the case that the portable telephone is used in the satellite communication system, the satellite system antenna/radio frequency unit
3
is connected to the interface
6
of the radio control unit
5
instead of the ground system antenna/radio frequency unit
1
.
Also, an internal arrangement of the satellite system antenna/radio frequency unit is similar to that of the ground system antenna/radio frequency unit
1
. In this case, the radio frequency unit
3
owns such a function to convert frequencies used in the satellite communication system, for instance, frequencies in 1.6 GHz and 2 GHz bands into IF frequencies.
Generally speaking, since the modulating systems, the information transfer speeds, and the protocol are different from each other in the ground communication system and the satellite communication system, these items should be switched. As a consequence, a demodulation control signal “a” and a modulation control signal “b” are sent from any one of the ground system antenna/radio frequency unit
1
or the satellite system antenna/radio frequency unit
3
to the demodulator
10
, the modulator
12
, and the baseband processing unit
11
employed in the radio control unit
5
, and thus these items are properly switched.
A demodulation control signal “a” and a modulation control signal “b” are outputted from any one of a ground system or a satellite system antenna/radio frequency unit. That is, the demodulation control signal “a” and the modulation control s
Green Miguel D.
Maung Nay
Rothwell Figg Ernst & Manbeck
LandOfFree
Mobile communication system does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Mobile communication system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Mobile communication system will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2985022