JP3300543B2 - Digital radio telephone equipment - Google Patents

Abstract

PURPOSE: To shorten time required for resynchronization or communication channel switching. CONSTITUTION: In the case of executing resynchronization at the occurrence of step-out on the mobile station side in a radio-telephone system for transmitting/receiving incoming and outgoing synchronizing bursts between a base station and a mobile station to synchronize both the stations and transmitting/receiving a communication channel to execute communication, the outgoing synchronizing burst (b) from the base station is continuously received twice or more. When the value of a counter (SSC) indicating the number of transmitting frames included in the final outgoing synchronizing burst (b) is a value obtained by adding '1' to the value of a counter (SSC) indicating the number of times of transmission included in the preceding outgoing synchronizing burst (b), the value of the final counter (SSC) is included in the incoming synchronizing burst (a) and transmitted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital wireless radio telephone, and more particularly to a protocol for establishing resynchronization in a weak electric field.

[0002]

2. Description of the Related Art A synchronous burst signal is a signal transmitted and received to establish synchronization when a communication channel is activated, when synchronization is lost during communication, and when the channel is switched. The format of this signal is as shown in FIGS. FIG. 1A shows an uplink (from a mobile station to a base station).
(B) is for downlink (from the base station to the mobile station). In the figure, G is a guard time, R is a guard time for burst transient response, P is a preamble, Post is a postamble, and S is a postamble.
W is a synchronization word, CC is a color code, TA is time alignment, B is a burst identification bit, SSC is a superframe synchronization counter, and Q is a tail bit (always 1). In addition, # 1, # 2, and # 3 perform error correction by performing majority processing for each bit with the same contents. When B = 0, TA and SSC are always 0, and when B = 1, TA,
Use SSC.

FIG. 5 is a flowchart of a conventional mobile telephone apparatus for transmitting and receiving a synchronous burst signal for establishing a communication channel (TCH) on the mobile station side. The operation for achieving synchronization will be described with reference to this flowchart.

When the control flowchart of the control channel is completed, a sequence for starting the communication channel (TCH) is started (200).

[0005] First, reception processing of the downlink synchronization burst SB1 is performed (201), and it is determined whether the downlink synchronization burst SB1 has been correctly received by checking the synchronization flag of the downlink synchronization burst SB1 (202). If the synchronization flag is not set, the downlink synchronization burst SB
1 is received (201), and if the synchronization flag is set, the color code CC of the received synchronization burst SB1 is received.
It is checked whether or not is specified by the management side (203). If it matches the one specified by the management side, the process proceeds to the transmission process (204) of the uplink synchronization burst SB2, and if not, the process returns to the reception process (201) of the downlink synchronization burst SB1 again.

After transmitting the uplink synchronization burst SB2, the downlink synchronization burst SB3 is received (205). The burst identification bit B is detected, and if this is 1, it is determined to be SB3 (206), and thereafter, the downlink synchronization burst SB3
The value of the superframe synchronization counter SSC received in step (1) is set in the uplink synchronization burst SB4 (207), and the received color code CC, time alignment TA, and burst identification bit B are further added to the uplink synchronization burst SB4.
Is transmitted (208).

[0007] If SB3 is not recognized in the determination of the burst identification bit B, transmission processing (204) of the uplink synchronization burst SB2 is performed again.

After transmitting the uplink synchronization burst SB4, the process enters a receiving process of the downlink communication channel TCH (209). After the reception, it is checked whether or not the frame synchronization flag is set (210). If the synchronization flag is set, the uplink communication channel TCH is transmitted (211). If the synchronization flag is not set, the superframe synchronization counter S
The value of the SC is incremented by +1 (212), the value of the superframe synchronization counter SSC is set in the uplink synchronization burst SB4 (207), and the uplink synchronization burst SB is set.
4 is returned (208).

After transmitting the uplink communication channel TCH,
The process returns to the control flowchart during communication (213).

That is, as shown in FIG. 6, synchronization bursts SB1 to SB4 are transmitted and received from the base station and the mobile station.

Incidentally, such a conventional control flowchart has the following disadvantages.

(1) One is that after receiving the downlink synchronization burst SB3, the value of the superframe synchronization counter SSC obtained from the reception is set in the uplink synchronization burst SB4 and transmitted. If the value of the superframe synchronization counter SSC of the downlink synchronization burst SB3 is erroneously received, the mobile station continues to transmit the incorrect superframe synchronization counter SSC while incrementing the value by +1. Even if SB3 is transmitted, the communication channel TCH is difficult.
There is a problem that it does not reach the transmission and reception of the.

(2) Next, when shifting from transmission / reception of the synchronization burst SB to transmission / reception of the communication channel TCH, the synchronization word S
Synchronization is established by a single match of W (32 bits). However, at the time of a weak electric field, there is a possibility that erroneous synchronization is caused by random noise. Then, even though the mobile station is transmitting the communication channel TCH as uplink transmission data, the base station has to transmit the downlink synchronization burst SB3 again and return to the process of receiving the synchronization burst again. It takes longer to start.

[0014]

As described above, in the conventional synchronization control method, once the value of the superframe synchronization counter SSC of the downlink synchronization burst SB3 is erroneously received, it is difficult to proceed to transmission / reception of the communication channel TCH. In addition, when the transmission and reception of the synchronization burst SB is shifted to the transmission and reception of the communication channel TCH, it may be time consuming without knowing whether the communication is the synchronization burst SB or the communication channel TCH. An object of the present invention is to solve this problem and reduce the time required for resynchronization and switching to a communication channel.

[0015]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides transmission and reception of uplink and downlink synchronization bursts between a base station and a mobile station for synchronization, and performs communication by transmitting and receiving a communication channel. In the digital radio telephone device, when the mobile station loses synchronization and resynchronizes, receiving means for continuously receiving the downlink synchronization burst from the base station a plurality of times; and The value of the counter indicating the number of transmissions included in the synchronization burst is compared with the value of the counter indicating the number of transmissions included in the downlink synchronization burst one time before the last time, and the value of the counter at the last time is 1
A comparing and judging means for judging that the value is one more than the value of the counter before, and when the comparing and judging means judges that the value is correct, the counter value of the last time is included in the uplink synchronization burst. And transmitting means for transmitting.

Further, the mobile station is provided with a judging means for judging whether or not to resynchronize from the contents of the format data included in the downlink synchronization burst even if the communication channel malfunctions.

[0017]

According to the present invention, the value of the counter is not fixed once, but is determined from two synchronization bursts. Therefore, the synchronization control may be disturbed by a malfunction due to short-term random noise or the like. By determining the contents of the format data, it is possible to prevent a situation in which a synchronization burst and a communication channel are erroneously determined and time is required until resynchronization is established.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A digital radio telephone according to the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 shows a synchronous burst signal used in the present invention, and FIGS. 2 and 3 are flowcharts of a start-up sequence of a communication channel TCH according to one embodiment of the present invention. FIG. 4 shows a procedure for transmitting and receiving a synchronous burst signal. FIG. 1 is the same as the above-described prior art, and the description is omitted here. The operation will be described with reference to the flowcharts of FIGS.

The control channel control flowchart ends, and the activation sequence of the communication channel TCH starts (100). First, reception processing of the downlink synchronization burst SB1 is performed (101), and it is determined whether the downlink synchronization burst SB1 has been correctly received by checking the synchronization flag of the downlink synchronization burst SB1 (102). If the synchronization flag is not set, the downlink synchronization burst S
When the synchronization flag is set, the color code C of the received synchronization burst SB1 is received.
It is checked whether C is specified by the management side (103). If it matches the one specified by the management side, the uplink synchronization burst SB2
To the transmission process (104), and if they do not match, the process returns to the reception process (101) of the downlink synchronization burst SB1 again.

After transmitting the uplink synchronization burst SB2, the downlink synchronization burst SB3 is received (105). If the burst identification bit B is 1, if it is 1, it is determined that it is SB3 (106). If it is the downlink synchronization burst SB3, the value of the received superframe synchronization counter SSC is set to R.
It is temporarily stored in the AM (107). Next, the downlink synchronization burst SB3 is received again (108), and the burst identification bit B is also determined to be SB3 from the burst identification bit B (10).
9) If it is SB3, the value of the received superframe synchronization counter SSC is compared with the value stored in the RAM (110), and the value obtained by incrementing the stored value of the second received value by +1 is stored. (1
11).

First and second downlink synchronization burst SB3
Returns to 104 again when it is determined that B is 0 and not SB3 in the reception, or when the value of the superframe synchronization counter SSC is not incremented by +1 as a result of receiving the second downlink synchronization burst SB3. And transmits an uplink synchronization burst SB2.

When the value of the superframe synchronization counter SSC has been incremented by +1 assuming that the value of the electric field is good and the data has been correctly received, the value of the second superframe synchronization counter SSC is set in the transmission data. (112), and transmits the uplink synchronization burst SB4 (113).

After transmitting the uplink synchronization burst SB4, the process proceeds to the receiving process of the downlink communication channel TCH (114). After the reception, it is confirmed whether or not the synchronization flag of the frame synchronization is set (115). If the synchronization flag is set, the content of the received data, that is, the color code CC, the time alignment TA, the burst identification bit B, the super frame The value of the synchronization counter SSC is read in the format of the synchronization burst SB (116), and it is determined whether the data can be read and is a correct value (117). If the data is read correctly, the superframe synchronization counter SSC
Is incremented by +1 (119), and the process returns to the transmission of the uplink synchronization burst SB4 (113).

When data cannot be read correctly in the format of the synchronous burst SB, the uplink communication channel TCH is transmitted (118). This means that the communication channel has been activated.

As described above, according to the present invention, (1) the value of the superframe synchronization counter SSC is not determined by only one reception of the downlink synchronization burst SB3, but is determined by receiving it twice. This eliminates the need for returning to the control channel and re-establishing synchronization every time the value of the superframe synchronization counter SSC is erroneous, thereby shortening the time required for restarting the communication channel TCH.

(2) Even if the frame synchronization of the communication channel TCH is once established, the reception burst is read in the burst format of the synchronization burst.
B4 cannot be received correctly, and a malfunction can be dealt with by transmitting the downlink synchronization burst SB3.
The time required for restarting the CH can be shortened.

[0028]

As described above, according to the present invention, the present invention relates to a digital radio system for transmitting and receiving synchronization by transmitting and receiving uplink and downlink synchronization bursts between a base station and a mobile station, and transmitting and receiving a communication channel to perform communication. In the telephone device, when re-synchronization occurs due to loss of synchronization, the mobile station continuously receives downlink synchronization bursts from the base station a plurality of times, and indicates the number of transmissions included in the final downlink synchronization burst. Is compared with the previous value, and it is determined that the value of the last time is one more than the value of the previous time. The transmission is included in the uplink synchronization burst.

Furthermore, even if the communication channel malfunctions, it is determined whether or not resynchronization is to be performed based on the contents of the format data included in the downlink synchronization burst.

As a result, it is possible to prevent the synchronization control from being disturbed by a malfunction due to short-term random noise or the like, and to shorten the time required for restarting the communication channel TCH.

[Brief description of the drawings]

FIG. 1 shows a format of a synchronous burst signal used in a digital radio telephone device in which the present invention is implemented.

FIG. 2 is a flowchart (part 1) of a communication channel activation sequence in one embodiment of the present invention.

FIG. 3 is a flowchart (part 2) of a communication channel activation sequence according to the embodiment of the present invention.

FIG. 4 is a diagram showing a procedure for transmitting and receiving a synchronous burst signal between a base station and a mobile station in one embodiment of the present invention.

FIG. 5 is a flowchart of a communication channel activation sequence in a conventional example.

FIG. 6 is a diagram showing a transmission / reception procedure of a synchronous burst signal between a base station and a mobile station in a conventional example.

[Explanation of symbols]

 B burst identification bit CC color code G guard time P preamble Post postamble Q tail bit SB synchronization burst R guard time for burst transient response SSC superframe synchronization counter SW synchronization word TA time alignment TCH communication channel

Claims (2)

(57) [Claims] 1. A digital radio telephone apparatus for performing synchronization by transmitting and receiving uplink and downlink synchronization bursts between a base station and a mobile station and transmitting and receiving a communication channel to perform communication, wherein the mobile station loses synchronization. When performing resynchronization, receiving means for continuously receiving the downlink synchronization burst from the base station a plurality of times, and changing the value of a counter indicating the number of transmissions included in the last downlink synchronization burst from the last time Comparing with a counter value indicating the number of transmissions included in the previous downlink synchronization burst,
A comparing and judging means for judging whether or not the value of the counter of the last time is a value correctly incremented by one from the value of the counter of the last time; and the value of the counter of the last time is correct by the comparing and judging means. Transmitting means for transmitting the final value of the counter included in the uplink synchronization burst when the determination is made. 2. The digital radio according to claim 1, wherein the mobile station further comprises: a judging unit for judging whether resynchronization is to be performed based on contents of format data included in the downlink synchronization burst. Telephone equipment.