Patent EP0891060A2 successfully refreshed from Google Patents.
EP0891060A2
Expired / Lapsed
EP
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Link setup, which allows several modulation formats
Assignee: Panasonic Holdings Corp
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Filing: 1998-06-30
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Granted: —
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Expires: 2018-06-30
Abstract
Abstract To perform communication at a higher speed than in the past using a new communication device without giving influence on the existing slave communication device, on a master device of a communication system such as PHS, there are provided two series of modulators and demodulators for conventional speed and for higher speed, the two different speeds being changeable by a changeover switch. A slave device to be added newly is also designed in almost the same configuration. In the link setup phase, an information to request change of modulation method is notified together with a request of communication from the slave device to the master device. From the master device, an information to specify time slots to be used in the communication phase and an information to specify modulation method are notified to the slave device. In the communication phase, communication is performed using the modulation method and the time slots as specified. The slave device can select the modulation method corresponding to the transmitting speed as required. In case the modulation method is not specified from the slave device, the same modulation method as that of the link setup phase is used in the communication phase, and the existing slave device not equipped with the means to specify the modulation method can be used without any change.
Inventors
- 👤 Tetsuya Nagai
- 👤 Naoya Morita
- 👤 Masahide Morozumi
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-31 22:28
CPC Classifications
H; H04; H04L; H04L5/00; H04L5/14; H04L5/1438; H04L5/1453; H04L27/00; H04L27/0008
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
220 words
A communication method for performing one-to-multiple
digital communication between a master device and a
plurality of slave devices, using a downward transmission frame to
transmit from said master device to said slave device and an
upward transmission frame to transmit from said slave device to
said master device, at least one of the downward and upward
transmission frames has a plurality of time slots, whereby, in a link
setup phase at the start of communication, an information to
specify time slot to be used in a communication phase is
transmitted using one time slot each of said upward transmission
frame and said downward transmission frame modulated by a first
modulation method, and in case high-speed communication is
performed, an information to specify a second modulation method
to provide transmission at higher speed than said first modulation
method is transmitted, and in case high-speed communication is
not performed, an information to specify the same second
modulation method as said first modulation method is transmitted,
or the information to specify the second modulation method is not
transmitted, and in the subsequent communication phase,
communication is performed using the time slot specified in said
link setup phase and by said second modulation method, and, in
case there is no information to specify said second modulation
method, said first modulation method can be selected.
Claim 2
Dependent Claim
39 words
A communication method according to claim 1,
wherein carrier frequency of a transmission frame using said
second modulation method used in said communication phase is
different from carrier frequency of the transmission frame used in
said link setup phase.
Claim 3
Dependent Claim
31 words
A communication method according to claim 1 or 2,
wherein multivalued number of modulation of said second
modulation method is higher than multivalued number of
modulation of said first modulation method.
Claim 4
Dependent Claim
29 words
A communication method according to claim 1 or 2,
wherein a symbol rate of said second modulation method is higher
than a symbol rate of said first modulation method.
Claim 5
Dependent Claim
186 words
A master device for performing communication using
the communication method according to one of claims 1 to 4,
wherein said master device comprises a data processing unit for
exchanging data to be transmitted or received and for allotting
time slots, a frame generating unit for inputting transmission data
from said data processing unit and for assembling a downward
frame with base band, a plurality of modulators having different
modulation methods, a first changeover switch for connecting said
frame generating unit to one of said plurality of modulators, a
transmission interface means for transmitting to a transmission
line, a second changeover switch for connecting the modulator
connected to said first changeover switch to said transmission
interface means, a receiving interface means for receiving data
from the transmission line, a plurality of demodulators for
demodulating signals with different modulation methods, a frame
disassembling unit for performing frame synchronizing of the
upward frame, for dividing the data to each time slot and for
delivering the data to said data processing unit, and a third
changeover switch for connecting one of said plurality of
demodulators to said frame disassembling unit.
Claim 6
Dependent Claim
210 words
A slave device for performing communication by the
communication method according to one of claims 1 to 4,
comprising a data processing unit for picking up only data of the
time slot directed to own station from received signal and for
outputting the data, and for inputting transmission data and for
delivering the data to a time slot generator, a time slot generator
for outputting a transmission data base band signal from said data
processing unit to a time slot which allows transmission, a plurality
of modulators having different modulation methods, a first
changeover switch for connecting said time slot generator to one
of said plurality of modulators, a transmission interface means for
transmitting the data to a transmission line, a second changeover
switch for connecting the modulator connected to said first
changeover switch to said transmission interface means, a
receiving interface means for receiving data from a transmission
line, a plurality of demodulators for demodulating signals having
different modulation methods, a frame disassembling unit for
performing frame synchronizing of a downward frame, for dividing
the received data to each time slot, and for delivering the data to
said data processing unit, and a third changeover switch for
connecting one of said plurality of demodulators to said frame
disassembling unit.
Claim 7
Dependent Claim
91 words
A data transmission method for performing data
transmission from a center device to a plurality of terminal device
using a frame at a given cycle, whereby said frame comprises a
common unit to be received by all of the terminal devices and an
individual unit to be received by a part of the terminal devices, and
said common unit is transmitted by a first modulation method and
said individual unit is transmitted by a second modulation method
having higher number of transmittable bits per unit time than said
first modulation method.
Claim 8
Dependent Claim
25 words
A data transmission method according to claim 7,
wherein said first modulation method is π/4 shift QPSK and said
second modulation method is 16 QAM.
Claim 9
Dependent Claim
25 words
A data transmission method according to claim 7,
wherein said first modulation method is π/4 shift QPSK and said
second modulation method is 8 PSK.
Claim 10
Dependent Claim
27 words
A data transmission method according to claim 7,
wherein symbol rate of said second modulation method is made
equal to symbol rate of said first modulation method.
Claim 11
Dependent Claim
25 words
A data transmission method according to claim 10,
wherein said first modulation method is π/4 shift QPSK and said
second modulation method is 16 QAM.
Claim 12
Dependent Claim
25 words
A data transmission method according to claim 10,
wherein said first modulation method is π/4 shift QPSK and said
second modulation method is 8 PSK.
Claim 13
Dependent Claim
140 words
A data communication system for communication
between a center device and a plurality of terminal devices,
whereby said center device forms a frame at a given cycle, said
frame comprising a common unit to be received by all of the
terminal devices so that data transmission is performed from said
center device to said terminal device and an individual unit to be
received by a part of the terminal devices, said common unit is
modulated by a first modulation method, said individual unit is
modulated by a second modulation method having higher number
of transmittable bits per unit time than said first modulation method,
said part of the devices demodulates said common unit by a first
demodulation method corresponding to said first modulation
method and demodulates said individual unit by a second
demodulation method corresponding to said second demodulation
method.
Claim 14
Dependent Claim
125 words
A center device in a data communication system for
performing communication between a center device and a plurality
of terminal devices, whereby said center devices at least
comprises a frame forming means for forming a frame at a given
cycle, said frame containing a common unit to be received by all
terminal devices so that data transmission can be performed from
said center device to said terminal devices and an individual unit
to be received by a part of the terminal devices, a first modulation
means for modulating said common unit by a first modulation
method, and a second modulation means for modulating said
individual unit by a second modulation method having higher
number of transmittable bits per unit time than said first
modulation method.
Claim 15
Dependent Claim
148 words
A terminal device in a data communication system
for performing communication from a center device to a plurality of
terminal devices, whereby said center device forms a frame at a
given cycle, said frame containing a common unit to be received
by all terminal devices and an individual unit to be received by a
part of the terminal devices, said common unit is modulated by a
first modulation method, and said individual unit is modulated by a
second modulation method having higher number of transmittable
bits per unit time than said first modulation method, a terminal
device in said part of the terminal device at least comprises a first
demodulation means for demodulating said common unit by a first
demodulation method corresponding to said first modulation
method, and a second demodulation means for demodulating said
individual unit by a second demodulation method corresponding to
said second modulation method.
References Cited (Backward Citations)
No citation records indexed.
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