Pulse or digital communications – Spread spectrum – Frequency hopping
Reexamination Certificate
1998-03-11
2001-04-03
Pham, Chi (Department: 2631)
Pulse or digital communications
Spread spectrum
Frequency hopping
C370S436000, C370S478000
Reexamination Certificate
active
06212221
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a wireless communicating apparatus for performing a communication by using a spread spectrum communication method.
2. Description of the Related Art
In a communicating system using the spread spectrum communicating method, a communicating method using a frequency hopping method (hereafter, referred to as an FH method) is used in order to improve the effective utilization of a frequency and a security. The FH method performs the spreading by hopping a carrier frequency in accordance with a predetermined rule based on a spread spectrum code sequence. A sending and receiving device in a two-way communicating system using the spread spectrum communicating method by the FH method is constructed, for example, as shown in FIG.
30
.
At first, when the sending operation is performed, a signal having a random frequency is outputted by a frequency synthesizer
206
in accordance with the spread spectrum code sequence outputted by a spread spectrum code sequence generator
205
. On the other hand, a first modulation signal is inputted to a transmission data input terminal
220
. An output frequency of the first modulation signal is determined by an up-converter
203
on the basis of the output of the frequency synthesizer
206
. The transmission data which is frequency-converted by the up-converter
203
is amplified by an amplifier
208
. Then, it is sent and outputted through a sharing element
210
to an antenna
211
.
Next, when the receiving operation is performed, a signal received by the antenna
211
is separated from the transmission signal by the sharing element
210
, amplified by an amplifier
209
and inputted to a down-converter
207
. Then, it is frequency-converted on the basis of a signal specifying the frequency from the frequency synthesizer
206
by the down-converter
207
, and demodulated by a demodulator
212
to thereby become the reception data. This reception data is outputted to a data operation circuit (not shown) and also outputted to a synchronization circuit
204
. In the synchronization circuit
204
, a phase of a hopping frequency is detected from the reception signal. A synchronization signal is outputted from the synchronization circuit
204
to the spread spectrum code sequence generator
205
, which outputs the spread spectrum code sequence on the basis of the inputted synchronization signal. The spread spectrum code sequence outputted by the spread spectrum code sequence generator
205
is sent to the frequency synthesizer
206
, which generates the output having the random frequency on the basis of the inputted spread spectrum code sequence.
The down-converter
207
multiplies the reception signal by the output from the frequency synthesizer
206
to thereby inverse-spread to the reception signal (Here, “inverse-spread” means to demodulate a signal modulated (spread) on the basis of a spread spectrum code by using the same spread spectrum code). The reception signal inverse-spread by the down-converter
207
is demodulated by the demodulator
212
. The demodulated reception signal is outputted from a reception data output terminal
221
.
Accordingly, the two-way communication is performed by the simultaneous operations in the sending and receiving sections as mentioned above.
The random frequency implies that the outputted spread spectrum code is randomly changed each time the synchronization signal is inputted by the spread spectrum code sequence generator
205
. The sending and receiving operations are performed under the common utilization of this spread spectrum code sequence (frequency hopping pattern) between one combination of communicating apparatuses.
However, in the conventional apparatuses, the data treated as the transmission data and reception data is only voice data or only non-voice data. Thus, it is impossible to send and receive the mixture of the voice data and the non-voice data.
This is because the uniformly sending and receiving operation is performed independently of the data types although there are the differences between the data characteristics, as described below. Namely, as for the voice data, the data amount which is sent and received at one time is small, and the ability of the real time (the ability of immediate response) is highly required. As for the non-voice data, the data amount which is sent and received at one time is large, and the ability of the real time is not required so much.
Hence, in an apparatus having both functions of a facsimile function and a master and slave phone function, a spread spectrum digital communication, such as the frequency hopping method or the like, can not be performed between the master phone and the slave phone. As a result, it is impossible to improve the security and the frequency utilization efficiency.
Moreover, in the conventional apparatus, in order to perform the simultaneous communications between the master phone and a plurality of slave phones, a hopping frequency data pattern must be changed for each communicating pair, and a plurality of sending and receiving devices must be disposed on the master phone side, which results in the problem of a large-sized apparatus.
SUMMARY OF THE INVENTION
It is therefore a first object of the present invention to provide a communication apparatus for performing the spread spectrum digital communication, which can simultaneously perform the communications by using a plurality of communication pairs.
Further, it is a second object of the present invention to provide a communicating apparatus for performing the spread spectrum digital communication, which can simultaneously process both the voice data and the non-voice data.
Furthermore, it is a third object of the present invention to provide a communication apparatus for performing the spread spectrum digital communication, which can perform an effective communication under a simple configuration, and perform an excellent communications without the interference with the mutual communications.
According to the present invention, the above mentioned first object is achieved by a communication apparatus having a master device connected with a plurality of outside lines for performing an outside communication of communication data between the master device and the plurality of outside lines, and a plurality of slave devices wirelessly connected with the master device for performing a communication of the communication data between the master device and the plurality of slave devices by using a spread spectrum communication method, the communication of the communication data between the master device and the plurality of slave devices being performed for each communication frame which indicates an unit of the communication on the basis of the spread spectrum communication method, the master device having: a first communicating device for performing the outside communication of the communication data between the master device and the plurality of outside lines; a converting device for converting a first format of the communication data received from the plurality of outside lines into a second format which can be handled by the master device, and for converting the second format of the communication data received from the plurality of slave devices into the first format which can be handled by the plurality of outside lines; an allocating device for dividing the communication frame into at least a first slot and a second slot, for allocating the first slot to the communication data to be used for performing a first communication between the master device and a first slave device among the plurality of slave devices, and for allocating the second slot to the communication data to be used for performing a second communication between the master device and a second slave device among the plurality of slave devices; and a second communicating device for performing simultaneously the first communication of the communication data between the master device and the first slave device by using the first slot, and t
Taki Kazunari
Wakayama Hironobu
Brother Kogyo Kabushiki Kaisha
Oliff & Berridge PLC.
Pham Chi
Phu Phuong
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