Multiplex communications – Fault recovery – Bypass an inoperative switch or inoperative element of a...
Reexamination Certificate
2001-01-09
2004-11-02
Pezzlo, John (Department: 2662)
Multiplex communications
Fault recovery
Bypass an inoperative switch or inoperative element of a...
C370S335000, C370S535000, C455S561000
Reexamination Certificate
active
06813239
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a radio base station communications apparatus for mobile communication wherein an information signal on which signals spread with codes orthogonal to each other are code division multiplexed is communicated between a base station and a child station by a code division multi access (Code Division Multi Access, CDMA) system which uses a spread spectrum technique for radio transmission, and particularly to a dual transmission spread processing circuit system for a radio base station communications apparatus.
2. Description of the Related Art
A basic construction of a dual system for a conventional transmission spread processing section of a communication base station apparatus of the CDMA system as described above is shown in FIG.
8
.
Referring to
FIG. 8
, in the conventional transmission spread processing section shown, two first and second transmission spread processing circuits
101
a
and
101
b
form a dual configuration and are individually connected in parallel to a channel coding processing circuit
102
, a radio transmission circuit
103
and a call connection and supervision control circuit
104
.
A transmission baseband signal before spread from the channel coding processing circuit
102
is inputted to the two transmission spread processing circuits
101
a
and
101
b
, in each of which it is spread modulated and addition synthesized by a spread processing circuit
105
. Then, synthesis spread signals from the spread processing circuits
105
are sent to the radio transmission circuit
103
. In the inside of the radio transmission circuit
103
, the synthesis spread signals from the two transmission spread processing circuits
101
a
and
101
b
are added to each other by an inputting section of the radio transmission circuit
103
. Then, the addition synthesis signal is inputted to a transmission circuit which performs quadrature amplitude modulation and radio frequency amplification.
The channel coding processing circuit
102
and the two transmission spread processing circuits
101
a
and
101
b
are connected to the call connection and supervision control circuit
104
by a control bus
112
so that coding processing information, spread processing information, signaling control information and so forth are communicated between them.
Subsequently, details of the internal configuration of each of the transmission spread processing circuits
101
a
and
101
b
are described.
A transmission baseband signal on which data of a plurality of channels are time division multiplexed is inputted from the channel coding processing circuit
102
to the transmission spread processing circuits
101
a
and
101
b
. In each of the transmission spread processing circuits
101
a
and
101
b
, data of the individual channels are demultiplexed from the transmission baseband signal and converted into user data having data rates defined for individual users by the channel data demultiplexing circuit
106
. The spread processing circuit
105
receives the plurality of user data having the different data rates, performs spread modulation for transmission for the user data and outputs spread signals for the individual users.
An addition synthesizer
107
adds all of the spread signals for the different users to obtain a synthesis spread signal and outputs the synthesis spread signal to the radio transmission circuit
103
through a switch circuit
108
. The channel data demultiplexing circuit
106
, spread processing circuit
105
and switch circuit
108
are all controlled by software of a processor circuit
109
. The processor circuit
109
is connected to the call connection and supervision control circuit
104
over the control bus
112
outside the transmission spread processing circuit
101
a
(
101
b
) so that it may principally communicate spread process information and signaling control information with the call connection and supervision control circuit
104
. Further, the processor circuit
109
receives alarm-switching information from an alarm and switching processing circuit
110
and signals it to the call connection and supervision control circuit
104
over the control bus
112
.
Such a conventional dual configuration of transmission spread processing circuits as described above must have a function that, if a failure occurs with either one of the two dual transmission spread processing circuits
101
a
and
101
b
, then processing which has been performed by the transmission spread processing circuit with which the failure has occurred is compensated for by the other normal transmission spread processing circuit.
In a normal state in which none of the two transmission spread processing circuits suffers from a failure, only one of the dual transmission spread processing circuits performs processing of the dual portions of the apparatus. Thus, an element or elements of dual components which are operating are hereinafter referred to as operating system. In this instance, the operating system assumes transmission spread processing while the is in a standby state and systematically does not contribute to the transmission spread processing in the normal state. Thus, an element or elements of dual components which stand by are hereinafter referred to as standby system. In this instance, when a failure occurs with the operating system, switching to the standby system is performed. An apparatus or system of the type described is generally called set standby switching system or hot standby system.
Applying this to
FIG. 8
, it is assumed that the first transmission spread processing circuit
101
a
is the operating system and the second transmission spread processing circuit
101
b
is the standby system. In the normal state, all transmission spread processing as the transmission spread processing section is performed by the transmission spread processing circuit
101
a
of the operating system, and the transmission spread processing circuit
101
b
of the standby system is in a standby state and does not at all share transmission spread processing required for the apparatus then.
If a failure occurs with the transmission spread processing circuit
101
a
of the operating system, then this is first detected by the alarm and switching processing circuit
110
in the transmission spread processing circuit
101
a
, and the detection information is sent to the processor circuit
109
. From the processor circuit
109
, the detection information is transmitted to the call connection and supervision control circuit
104
over the control bus
112
outside the transmission spread processing circuit
101
a
. The call connection and supervision control circuit
104
receives the failure detection information and performs switching control to the standby system.
Here, as operation of the transmission spread processing circuit
101
b
of the standby system in its standby state, it is desirable from the point of view of minimization of the time of the switching process that it executes processing quite same as the transmission spread processing of the operating system but only its transmission output is stopped at the switch circuit
108
of the standby system. The switching process performed by the call connection and supervision control circuit
104
where the standby system operates in this manner is to control the switch circuit
108
in the failed transmission spread processing circuit
101
a
of the operating system so that the transmission output of the transmission spread processing circuit
101
a
is stopped and simultaneously control the switch circuit
108
of the standby system so that transmission may be performed from the transmission spread processing circuit
101
b
of the standby system.
Since the conventional system having such a configuration as described above performs output switching from the operating system to the standby system by hardware, restoration upon failure can be performed momentarily. However, since such a hardware configuration that the transmission spread processing circ
Dickstein Shapiro Morin & Oshinsky LLP.
NEC Corporation
Pezzlo John
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