JP2984756B2 - Portable wireless communication terminal - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a portable radio communication terminal device for performing communication in a TDMA-TDD system, and more particularly to a technology of frame synchronization for reception.

[0002]

2. Description of the Related Art In portable radio communication terminals such as PHP (Personal Handy Phone), TDMA-TD
Communication using the D method (TDMA: Time Division Multip
le Access, TDD: Time Division Duplex).

A mobile station (PS: Personal Station) detects a synchronizing word (unique word: UW) from a signal received from its own base station (CS: Cell Station), and transmits and uses this as a time reference. Set the reception timing. This is called reception frame synchronization.

Conventionally, a mobile station (PS) performs reception frame synchronization using a circuit as shown in FIG. FIG.
, 1 is a unique word detector, 2 is a received signal processing counter, 3 is a received signal processor, 4 is a descrambler, 5 is a CRC calculator (CRC: Cyclic Redundancy Ch).
ech) and 6 are reception frame counters.

When a pattern of a synchronizing word (unique word) is detected from the received data by the unique word detecting unit 1, a detection pulse of the synchronizing word (unique word) is generated, and the received signal processing counter 2 detects the detected pulse. Triggers the received signal processing count. Based on the count value, the reception signal processing unit 3 that performs signal processing of the reception data, such as the descrambler 4 and the CRC calculation unit 5, is turned on.
/ OFF timing is generated. When the count value reaches a predetermined value, this signal processing ends and a count end pulse is generated. At this time, the processing by the CRC calculation unit 5 is also completed, and the C
An RC check is performed and output to the reception frame counter 6. When there is no error, the reception frame counter 6 is reset and starts counting. When the unique word detector 1 detects a synchronizing word (unique word) from the received data, the receiving frame counter 6 is reset and starts counting.

The position of the next received frame is predicted from the count value of the received frame counter 6, the unique word detector 1 is enabled at that position, and the next synchronizing word (unique word) is waited for. Synchronous word (unique word)
Is detected again, the reception frame counter 6 is reset again, and this timing is used as a new reference. If the synchronization word (unique word) is not detected, the counting is continued and the previous synchronization word (unique word)
Is used as a reference. The same operation is performed in the next frame to maintain the synchronization of the received frame.

[0007]

However, if a synchronization word (unique word) is erroneously detected, or if synchronization with another station is caused by interference from another station, the reception frame counter 6
Is reset at the wrong timing, and frame synchronization is lost.

[0008] The present invention has been made in view of the above circumstances, and even when a synchronization word (unique word) is erroneously detected, or when synchronization with another station is caused by interference of another station, It is intended to protect frame synchronization.

[0009]

SUMMARY OF THE INVENTION A portable radio communication terminal device according to the present invention detects a synchronizing word from received data to generate a detection pulse, and receives the detection pulse to perform a reception signal process. The counting means starts counting, generates ON / OFF timing of descrambling and CRC calculation, and further generates a count end pulse when the count value reaches a predetermined value. Means for performing a certain CRC check; frame counting means for starting counting after being reset, predicting the next received frame position based on the count value, and enabling the detecting means at that position, and a result of the CRC check When there is an error, mask the count end pulse and reset the frame count means Causes prohibited, it is characterized in that a gate means for resetting said frame counting means by passing said count end pulse when no error.

As a gate means, a signal indicating whether or not there is an error in the CRC check and a count end pulse are inputted.
A for outputting the result of the logical product to the frame counting means
ND gates can be used.

[0011]

When the result of the CRC check of the received data is incorrect, the timing of the frame is discarded, and the timing of the previously received frame is retained. If a sync word is erroneously detected, the result of the CRC check will be erroneous.
Prevent establishment of frame synchronization from erroneous detection of synchronization words. Also,
CR when receiving a transmission from the base station (CS) of another station
Since the C-check results in an error, the establishment of frame synchronization is protected from the interference of the base station of another station.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a portable radio communication terminal according to the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows a portable radio communication terminal device (P
FIG. 3 is a block diagram showing a configuration of a main part of HP). In FIG. 1, 1 is a unique word detector, 2 is a received signal processing counter, 3 is a received signal processor, 4 is a descrambler,
5 is a CRC calculation unit (CRC: Cyclic Redundancy Chech)
) And 6 are reception frame counters, and 7 is an AND gate.

FIG. 2 is a timing chart for explaining the operation of the embodiment. The unique word detection unit 1 generates a unique word detection pulse S2 when detecting a pattern of a synchronizing word (unique word) from the received data S1. The reception signal processing counter 2 starts the reception signal processing count S3 by using the unique word detection pulse S2 as a trigger. The descrambler 4, CR
Timings S4 and S5 for ON / OFF control of the reception signal processing unit 3 that performs signal processing of the reception data S1 such as the C calculation unit 5 are generated. When the count value reaches a predetermined value,
This signal processing ends, and a reception count end pulse S6 is generated. At this point, the processing S7 by the CRC calculation unit 5
Is also completed, and a CRC check, which is a determination as to whether or not there is an error in the received data, is performed. The reception signal processing counter 2 outputs a reception count end pulse S6 to the reception frame counter 6 at the end of counting. CRC check (S
7) As a result, when it is determined that there is an error in the reception data S1, the reception count end pulse S6 is masked by the AND gate 7 to inhibit the input of the reset pulse S8 to the reception frame counter 6, and the reception frame counter 6 is reset. Is not performed (see broken lines in S7 and S8). As a result,
The reception frame counter 6 holds the timing of a frame received before the present frame.

As a result of the CRC check (S7), if it is determined that there is no error in the received data, the reception count end pulse S6 is passed to the AND gate 7, a reset pulse S8 is output to the reception frame counter 6, and the reception frame counter 6 is reset (see the solid lines in S7 and S8), and the detection timing of the synchronization word (unique word) is reflected in the reception frame counter 6. As a result, the reception frame counter 6 holds the timing of this frame.

As described above, when the result of the CRC check of the received data is incorrect, the timing of the frame is discarded, and the timing of the previously received frame is retained. If a sync word (unique word) is incorrectly detected,
Since the result of the CRC check indicates an error, the frame synchronization is prevented from erroneously detecting the synchronization word (unique word).

In the physical communication slot of PHP,
CS-ID (Cell Station Ide
ntification), the CS (Cell S
tation: base station), the CRC check is also erroneous and protects frame synchronization from CS interference of other stations.

[0018]

According to the present invention, when the result of the CRC check of the received data is incorrect, the timing of the frame is discarded and the timing of the previously received frame is retained. If the synchronization word is erroneously detected, the result of the CRC check indicates an error, so that there is an effect that the establishment of frame synchronization is prevented from erroneously detecting the synchronization word. Also, when a transmission from the base station (CS) of another station is received, the CRC check becomes erroneous, so that there is an effect of protecting the establishment of frame synchronization from the interference of the base station of another station.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a portable wireless communication terminal device according to one embodiment of the present invention.

FIG. 2 is a timing chart for explaining the operation of the embodiment.

FIG. 3 is a block diagram illustrating a configuration of a portable wireless communication terminal device according to a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Unique word detection part 2 ... Reception signal processing counter 3 ... Reception signal processing part 4 ... Descrambler 5 ... CRC calculation part 6 ... Reception frame counter 7 ... AND gate

Claims (2)

(57) [Claims] 1. A detecting means for detecting a synchronizing word from received data to generate a detection pulse, and upon receiving the detection pulse, starting counting for reception signal processing and turning on / off descrambling and CRC calculation. And a means for generating a count end pulse when the count value reaches a predetermined value, a means for performing a CRC check for determining whether or not there is an error in received data, and starting counting after being reset. Frame counting means for estimating the next received frame position based on the count value and enabling the detection means at that position; and masking the count end pulse when the result of the CRC check indicates an error. In addition to prohibiting resetting of the counting means, when there is no error, It passed through a completion pulse, characterized in that a gate means for resetting said frame counting means portable radio communication terminal device. 2. The portable device according to claim 1, wherein the gate means is an AND gate which inputs a signal indicating whether or not there is an error in the CRC check and a count end pulse, and outputs the result of the logical product to the frame count means. Wireless communication terminal device.