JPH0870288A - Tdma communication equipment and its method - Google Patents

Abstract

PURPOSE: To receive accurately reception data with simple configuration by estimating and predicting a frequency deviation of a clock signal with respect to a base station. CONSTITUTION: The equipment is provided with a management section 50 that has a frame timing signal output means outputting a frame timing signal in a prescribed timing, detects a unique word signal UW included in a frame assigned to a concerned station and detects a phase difference between the unique word signal and the frame timing signal, an estimate section 600 that obtains a frequency deviation in the frame timing signal based on plural phase differences detected by the management section and estimates an output timing of the frame timing signal based on the frequency deviation, and a processing section 4 applying reception processing to the data signal included in the frame allocated to the concerned station, and the estimate section controls an output of the frame timing signal of the frame timing signal output means of the management section based on the result of estimate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to TDMA (Time).
Division Multiple Acces
The present invention relates to a communication device and a communication method using the (s: time division multiple access) method.

[0002]

2. Description of the Related Art The TDMA communication system is one of the systems in which a plurality of stations physically located at different positions divide the communication transmission line capacity and use time as a dividing means. The details of the TDMA communication are described in detail in Yamamoto and Kato: “TDMA communication” (The Institute of Electronics, Information and Communication Engineers).

FIG. 16 shows the concept of TDMA communication. A TDMA frame, which is the basic cycle of signal transmission / reception, is defined, and a signal is transmitted to the partner station using a fixed time width (time slot) assigned in this frame. Therefore, each station needs to adjust the transmission timing of each station so that transmission signals (burst signals) overlap each other in space and do not interfere with each other. Moreover, in order to communicate, each station needs a line through which a signal should be received. This line is composed of other time slots in the same frame in satellite TDMA communication.
On the other hand, in the terrestrial radio and mobile TDMA communication, the receiving station of the TDMA signal is the base station, and the line to be received by each slave station (station other than the base station) is composed of continuous TDMA lines from the base station. Below, the basic functions of TDMA communication are considered.

In the TDMA communication, since the lines of the same frequency are used in a time division manner, the transmission rate of the wireless line is made higher (usually several times to several thousand times) than that of the digital signal to be transmitted, and intermittent ( Information is transmitted and received (communication) by transmitting a wireless line signal in burst. In order to perform such TDMA communication, it is necessary to compress the time axis of a digital signal sent from a terminal or a terrestrial network and convert it into a high-speed burst. Conversely, the receiving side receives the high-speed signal sent in bursts and expands it to the clock speed signal of the terminal or the terrestrial network.
To do. The "compression / expansion" operation of this signal is one of the features of TDMA communication.

In order to prevent the burst signals transmitted from the stations from overlapping each other on the wireless line, it is necessary to control the transmission timing. Therefore, each station waits for a common “time reference”, and sets a transmission timing (transmission time reference) in consideration of a distance difference from each station to a receiving (base) station or a satellite (in the case of satellite TDMA communication). The former is reception synchronization because it detects a specific signal (reference station synchronization signal) from the received signals and uses it as a time reference, and the latter is transmission synchronization (or burst synchronization) because it determines the timing of the signal transmitted to the satellite. Is called. For example, in the example of FIG. 16, the mobile station i sends a signal to the time slot Ti on the TDMA frame. In this way, the signals transmitted from the respective stations are received by the base station without overlapping on the wireless line. In the case of TDMA satellite communication, these signals are amplified by a satellite repeater and transmitted to each earth station. Therefore, in the above example, the signal transmitted in the time slot Ti is taken in as a time slot to be received by the earth station, and conversely, the earth station communicates by taking in the signal sent from the earth station.

FIG. 16 shows the concept of the TDMA system. 12
1, 122 and 12i are mobile stations, 123 is a base station, t1,
t2 and ti are burst signals. In the TDMA method, a TDMA frame is defined as a basic cycle of a transmission interval (or a reception interval) of burst signals, and this frame is further divided into time slots having a constant time width. The mobile stations 121, 122, 12i receive the signal transmitted from the base station 123 to the mobile station, thereby subordinately synchronizing the frame and the time slot with the base station 123, and using the specific slot in this frame, the base station The burst signals t1, t2 and ti are transmitted to the station 123, respectively. Therefore, the mobile stations i1 to t1 can simultaneously transmit in one frame.

When performing communication by the TDMA system, the mobile station needs to synchronize the transmission / reception frame timing of its own station with the base station so as not to collide with burst signals of other stations. Further, since both the base station and the mobile station have independent clock sources, it is necessary to remove the frequency deviation between the clocks. The problem of how to realize so-called slave synchronization, in which the frame timing is synchronized with the base station and the synchronization is maintained while removing the frequency deviation of the transmission clock, is extremely important for the mobile station. A method of subordinate synchronization conventionally performed by a mobile station will be described.

FIG. 17 is a block diagram showing the structure of a conventional mobile station. 1 is an antenna, 2 is a transmitter, 3 is a receiver,
Reference numeral 4 is a transmission / reception data processing unit, and 50x is a timing management unit. 4i is transmission data, 4t is transmission burst data, 2t is a transmission signal, 3r is a reception signal, 4r is reception burst data, 4o is reception data, and 50a is a timing signal. The operation will be described below. Received signal 3r
Is a downlink signal from the base station, and is received and demodulated by the receiving unit 3 via the antenna 1. The demodulated reception burst data 4r is supplied to the timing management unit 50x, which extracts the burst reception timing and corrects the received reception frame timing. Further, the burst reception timing is provided to the transmission / reception data processing unit 4 as the timing signal 50a. The transmission / reception data processing unit 4 decomposes the reception burst data 4r and generates the transmission burst data 4t based on the timing signal 50a. The transmission burst data 4t is modulated / transmitted by the transmission unit 2 and brought to the base station via the antenna as a transmission signal 2t. The transmitting unit 2 and the receiving unit 3 are not directly related to the present invention, and therefore their explanations are omitted.

An example of the operation of the timing management unit 50x will be described in detail with reference to the block diagram of FIG. 51 is a unique word detector (UW detector), 52x is a frame counter, 53x is a window generator, 51a is a unique word detection pulse (UW detection pulse), 51b is a UW detection pulse after passing through a window, and 53a is a window signal. is there. Generally, in TDMA communication, the arrival time of a burst is captured on a bit-by-bit basis on the receiving side, so a known fixed pattern called a unique word UW having excellent autocorrelation characteristics is inserted in the burst signal. A UW detector detects this pattern and receives the received burst signal 4r as an input and outputs a UW detection pulse 51a. The frame counter 52x is a counter having a TDMA frame period and is initialized by the UW detection pulse 51b after passing the window. The window generator 53x receives the counter value of the frame counter 52x as an input and generates a window signal 53a with a predetermined counter value.

The operation of FIG. 18 will be described in time series with reference to FIG. In addition to the data, the received burst data 4r includes the above-mentioned UW pattern, preamble P, and data error detection bit FCS (Frame Check Sequence).
nc)). The UW detector 51 performs bit-by-bit autocorrelation detection, and when a pattern matching UW is detected in the received bit stream, UW detection is performed.
The detection pulse 51a is generated.

The mobile station detects UW from the received burst signals that periodically arrive and initializes the frame counter 52x with a UW detection pulse to establish / maintain slave synchronization. The UW detection pulse 51a includes so-called erroneous detection, which is accidentally detected as a correlation among thermal noise and random bits among data bits. False positives disturb subordinate synchronization,
It is extremely harmful because it hinders the extraction of the received burst data at the correct position and causes a collision with the transmission signal of another station due to generation of incorrect transmission timing. Therefore, TDMA
In communication, predict the arrival time of the reception burst in advance,
By opening the window before and after that and performing UW detection only within the window, UW erroneous detection is suppressed. Frame counter 52x with UW detection pulse 51b after passing window
A stable slave synchronization is realized by initializing. UW detection pulse 51b after passing through the window for some reason
If is not detected, the frame counter rotates at the frame cycle to hold the frame timing.
Timing A is the position of the UW detection pulse that has passed through the window, and at this timing the frame counter 52x
Is initialized. Further, the timing B shows the cycle of the frame counter, which is reset at the TDMA frame cycle, for example. Therefore, UW after passing Windu
When the detection pulse 51b is not detected, the UW detection timing after passing the last window detected is stored.

In a system using a battery as a power source, intermittent reception control for extending the reception interval during non-call is performed for battery saving. Taking the domestic standard of the simplified mobile phone system as an example, a mobile station used for public uses a TDMA frame of 5 ms, a TDMA frame period during a call, and a 240 TDMA frame period (1.2
sec) is specified. Note that such a rule is generally called intermittent reception control. For this reason,
The reception frame timing error caused by the frequency deviation of the transmission clock becomes remarkable during intermittent reception. This means that the window position opened by the mobile station deviates largely from the center of the UW detection pulse. If the amount of error exceeds 1/2 of the window width, the UW detection pulse will not enter the window width, so the window width must be made large, but this causes a problem in UW erroneous detection.

When continuous non-detection of UW often occurs due to a drop in reception level due to fading / shadowing, the mobile station cannot initialize the frame counter, and thus saves the UW detection timing last passed through the window. However, even in this case, the received frame timing error is accumulated.

Next, the problem of the received frame timing error when performing handoff between base stations will be described. In general, a mobile station performs channel switching called handoff in order to maintain a line when a level drop or reception quality drop occurs during communication or standby with the base station. This operation will be described with reference to FIGS. In FIG. 20, the mobile station 121 has the switching source base station 12
3 shows an example of handoff from 3a to the switching destination base station 123b. In this case, the base station 123a and the base station 1
Reception timing (slot) with 23b
Does not necessarily have a synchronous relationship with. In that case, the mobile station only subordinately synchronizes with the receiving base station, and the timing of other cells is unknown. Therefore, it is indispensable to re-acquire the reception timing due to handoff. In general, the line condition is not good when handoff is required, and UW continuous non-detection is likely to occur, and the reception frame timing error tends to increase.

For this reason, for example, in the domestic standard of the simplified mobile telephone system, a recalling type handoff algorithm as shown in FIG. 21 is adopted. That is,
When the mobile station 121 is in a communication 210 with the base station 123a and the level is lowered / reception quality is lowered 210, the mobile station 121 issues a link channel establishment request 211 to the base station 123b and receives a channel allocation 212. Then, after transmitting and receiving the synchronization bursts 213 and 214 to resynchronize from the beginning, the procedure for link establishment is performed 215,
The communication 216 is restarted. As described above, in order to execute the handoff, it is necessary to transmit and receive a large number of signals.

In order to save the battery effectively during intermittent reception, it is common to switch between the high-speed clock and the low-speed clock for use. The problem in this case will be described below. FIG. 22 shows an example of the clock switching operation during intermittent reception. When the intermittent reception is executed, the reception clock signal is used in the interval (intermittent reception interval) where the intermittent reception signal is received, and the intermittent clock signal is used in the non-reception interval (intermittent non-reception interval). For this reason,
It is necessary to switch the clock signal in the intermittent reception / intermittent non-reception section. As an example of an actual method of creating the reception clock and the intermittent clock signal, a method based on the block diagram of FIG. 23 is generally used. In the figure, 221 is a clock generator A, 222 is an M-stage frequency divider, 223 is an N-frequency divider, and 224 is a selection circuit. The received clock signal is the output of the clock generator A 221 divided by M by the M divider 222, and the intermittent clock signal is the output of the clock generator A by N.
It is the output divided by N by the frequency divider 223. In this example,
Since the reception clock signal and the intermittent clock signal have a synchronous relationship, the frame signals generated from the respective clocks also have a synchronous relationship.

In this method, however, the clock generator 22
It is not efficient because 1 is always in operation. As a method for improving this, for example, the method shown in the block diagram of FIG. 24 can be considered. In FIG. 24, 225 is a clock generator B
The other components are the same as those in FIG.
It is the same as the one except. The clock generator B225 is a low-speed clock oscillator dedicated to the intermittent clock signal, and operates only in the intermittent non-reception section. That is, the clock generator A of the high-speed clock system operates only in the intermittent reception section and stops in the intermittent non-reception section, which is extremely advantageous in terms of power saving. However, with the configuration of FIG. 24, since different original clocks are used, the continuity of frame timing is lost when the clocks are switched.

[0018]

Since the subordinate synchronization is based on the UW detection timing after passing through the window, the reception frame timing error becomes large in the intermittent reception and when the UW non-detection continues. Therefore, UW
If an incorrect received frame timing is set due to false detection, the timing error becomes even larger, interference with adjacent slots occurs, and extremely serious problems such as communication disruption occur. Further, in order to suppress the frequency deviation which is the cause of the reception frame timing error, it is necessary to prepare an expensive clock source, which causes a problem in downsizing and cost. The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a TDMA apparatus and method that can receive received data easily and accurately.

As another problem, when the base stations are not synchronized with each other, a large number of signals are exchanged during the handoff. Therefore, in the microcell / picocell communication in which the handoff frequently occurs, the system control channel is used. It causes the problem of increased traffic. Furthermore, since the synchronization needs to be restarted from the beginning, there is an essential problem that the handoff connection delay time is large.

Still another problem is that when different clock sources are used for intermittent reception, the reception frame timing continuity is lost when the clocks are switched due to the frequency deviation between the clocks. There is a problem that you need to open the.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to make it possible to receive received data easily and accurately.
An MA device and method are provided.

[0022]

TDMA according to the present invention
The communication device detects a phase difference between a timing signal output from the timing signal output means and a UW detection signal output from the detection means, and a base station and a slave station based on the detected phase difference. The frequency deviation of the timing signal existing between the two is calculated, the phase error in the next reception frame is predicted based on this frequency deviation, and the timing signal output means is notified.

Further, the TDMA communication method according to the present invention comprises a step of obtaining a frequency deviation of the timing signal based on the phase difference between the timing signal and the UW detection signal,
The method comprises a step of predicting a phase error in the next reception frame based on the frequency deviation and a step of correcting the output of the timing signal by the phase error.

Further, the TDMA communication apparatus according to the present invention comprises an estimation unit for deriving a prediction formula from a plurality of phase differences and estimating the phase error from the prediction formula.

Further, the TDMA communication apparatus according to the present invention is provided with an estimating unit for obtaining the frequency deviation based on the error information and the phase difference when the interference wave is received.

Further, the TDMA communication method according to the present invention comprises a step of obtaining the frequency deviation based on the error information and the phase difference when the interference wave is received.

Further, the TDMA communication apparatus according to the present invention is provided with an estimation unit for obtaining the frequency deviation based on the received electric field level information and the phase difference.

Further, the TDMA communication method according to the present invention comprises a step of obtaining a frequency deviation based on the received electric field level information and the phase difference.

Further, the TDMA communication apparatus according to the present invention is provided with an estimation unit for obtaining the frequency deviation based on the error information, the received electric field level information and the phase difference.

Further, the TDMA communication method according to the present invention comprises a step of obtaining the frequency deviation based on the error information, the received electric field level information and the phase difference.

Further, in the TDMA communication apparatus according to the present invention, the phase difference detecting means for detecting the phase difference between the timing signal output from the timing signal output means and the UW detection signal output from the detecting means is detected. A storage unit that stores the phase difference for each base station, and an instruction to switch the frequency of transmission and reception to the frequency synthesizer at the time of handoff, and a timing signal output unit that stores the phase difference between the switching target base station stored in the storage unit. And a control unit for notifying the user.

Further, the TDMA communication method according to the present invention comprises the steps of storing the phase difference between the timing signal and the UW detection signal, switching the transmission / reception frequency corresponding to the switching destination base station during handoff, and storing the same. And a step of notifying the timing signal output means of the phase difference between the switching destination base station.

Further, in the TDMA communication apparatus according to the present invention, the phase difference detecting means for detecting the phase difference between the timing signal outputted by the timing signal outputting means and the UW detection signal outputted by the detecting means is detected. Based on the phase difference, the frequency deviation of the timing signal existing between the base station and the mobile station is obtained, and based on this frequency deviation, the phase error of the timing signal in the next reception frame is predicted and output as correction information. An estimation unit, a storage unit that stores this correction information for each base station, and an instruction to switch the frequency of transmission and reception to the frequency synthesizer at the time of handoff, and a correction corresponding to the switching destination base station stored in the storage unit. And a control unit for notifying the timing signal output means of information.

Further, the TDMA communication method according to the present invention comprises a step of obtaining the frequency deviation of the timing signal based on the phase difference between the timing signal and the UW detection signal,
A step of predicting a phase error in the next reception frame from this frequency deviation and storing it as correction information, a step of switching the transmission / reception frequency corresponding to the switching destination base station at the time of handoff, and a stored switching destination The step of correcting the output of the timing signal based on the correction information corresponding to the base station.

Further, in the TDMA communication apparatus according to the present invention, the timing signal output from the timing signal output means and the UW detection signal from the adjacent base station output from the detection means are utilized by utilizing the intermittent non-reception section. The phase difference detecting means for detecting the phase difference of

Further, the TDMA communication apparatus according to the present invention utilizes the empty slot of the frame to detect the timing signal output from the timing signal output means and the UW detection from the adjacent base station output from the detection means. It is provided with a phase difference detecting means for detecting a phase difference with a signal.

Also, in the TDMA communication apparatus according to the present invention, the position of the timing signal output from the timing signal output means and the UW detection signal from the adjacent base station output from the detection means is utilized by utilizing the silent period. It is provided with a phase difference detecting means for detecting a phase difference.

Further, in the TDMA communication apparatus according to the present invention, the timing signal output means selects the receiving clock signal or the intermittent clock signal, and the clock timing for measuring the phase difference between the receiving clock signal and the intermittent clock signal. A management unit and a clock for estimating the frequency deviation between the received clock signal and the intermittent clock signal based on this phase difference, and controlling the period of the intermittent clock signal to be a common multiple of the period of the received clock signal based on the estimation result. And timing estimation means.

[0039]

In the TDMA communication apparatus according to the present invention, the phase difference detection means detects the phase difference between the timing signal output from the timing signal output means and the UW detection signal output from the detection means, and the estimation unit is detected. The frequency deviation of the timing signal existing between the base station and the slave station is obtained based on the phase difference, the phase error in the next reception frame is predicted based on the frequency deviation, and the timing error is notified to the timing signal output means.

In the TDMA communication method according to the present invention, the frequency deviation of the timing signal is obtained based on the phase difference between the timing signal and the UW detection signal, and the phase error in the next receiving frame is calculated from this frequency deviation. Predict,
Controls the output of timing signals.

Further, in the TDMA communication apparatus according to the present invention, the estimating section derives a prediction formula from a plurality of phase differences and estimates the phase error from this prediction formula.

Further, the TDMA communication apparatus according to the present invention obtains the frequency deviation based on the error information and the phase difference when the estimating unit receives the interference wave.

In the TDMA communication method according to the present invention, the frequency deviation is obtained based on the error information and the phase difference when the interference wave is received.

Further, in the TDMA communication apparatus according to the present invention, the estimating unit obtains the frequency deviation based on the received electric field level information and the phase difference.

Further, the TDMA communication method according to the present invention obtains the frequency deviation based on the received electric field level information and the phase difference.

Further, in the TDMA communication apparatus according to the present invention, the estimating unit obtains the frequency deviation based on the error information, the received electric field level information and the phase difference.

Further, the TDMA communication method according to the present invention obtains the frequency deviation based on the error information, the received electric field level information and the phase difference.

Further, in the TDMA communication apparatus according to the present invention, the phase difference detecting means detects the phase difference between the timing signal output from the timing signal output means and the UW detection signal output from the detecting means, and the storage means stores the phase difference. The detected phase difference is stored for each base station, and at the time of handoff, the control unit instructs the frequency synthesizer to switch the transmission / reception frequency, and at the same time, stores the phase difference with the switching destination base station stored in the storage means. Notify the timing signal output means.

Further, the TDMA communication method according to the present invention stores the phase difference between the timing signal and the UW detection signal, switches the transmission / reception frequency corresponding to the switching destination base station at the time of handoff, and stores the stored switching. The timing signal output means is notified of the phase difference from the previous base station.

Further, in the TDMA communication apparatus according to the present invention, the phase difference detecting means detects the phase difference between the timing signal output from the timing signal output means and the UW detection signal output from the detecting means, and the estimating section , The frequency deviation of the timing signal existing between the base station and the mobile station is obtained based on the detected phase difference, and based on this frequency deviation, the phase error of the timing signal in the next reception frame is predicted and the correction information The storage unit stores this correction information for each base station, and at the time of handoff, the control unit gives the frequency synthesizer an instruction to switch the transmission / reception frequency, and the switching destination base station stored in the storage unit. To the timing signal output means of the correction information corresponding to.

In the TDMA communication method according to the present invention, the frequency deviation of the timing signal is obtained based on the phase difference between the timing signal and the UW detection signal, and the phase error in the next receiving frame is calculated from this frequency deviation. It is predicted and stored as correction information, and at the time of handoff, the transmission / reception frequency corresponding to the switching destination base station is switched, and the output of the timing signal is controlled based on the stored correction information corresponding to the switching destination base station. .

Further, in the TDMA communication apparatus according to the present invention, the phase difference detection means uses the intermittent non-reception section, and the timing signal output from the timing signal output means and the adjacent base station output from the detection means. The phase difference with the UW detection signal from is detected.

Further, in the TDMA communication apparatus according to the present invention, the phase difference detecting means uses the empty slot of the frame, and the timing signal output from the timing signal output means and the adjacent signal output from the detecting means. UW from base station
The phase difference with the detection signal is detected.

Further, in the TDMA communication apparatus according to the present invention, the phase difference detection means utilizes the silent period to output the timing signal output from the timing signal output means and the adjacent base station output from the detection means. The phase difference from the UW detection signal is detected.

Further, in the timing signal output means of the TDMA communication apparatus according to the present invention, the selection means selects the reception clock signal or the intermittent clock signal, and the clock timing management means determines the phase difference between the reception clock signal and the intermittent clock signal. The clock timing estimating means estimates the frequency deviation between the received clock signal and the intermittent clock signal based on this phase difference, and the period of the intermittent clock signal becomes a common multiple of the period of the received clock signal based on this estimation result. To control.

[0056]

【Example】

Example 1. Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of this embodiment.
In FIG. 1, 50 is a timing management unit, 600 is an estimation unit, 50b is phase error information, 600a is correction information, and others are the same as in FIG. The timing management unit 50 corresponds to a management unit, and the transmission / reception data processing unit corresponds to a processing unit. The operation will be described below with reference to FIG. The transmission unit 2, the reception unit 3, the transmission / reception data processing unit 4, and the transmission data 4i and the transmission burst data 4 which are their input / output signals.
Since t, the transmission signal 2t, the reception signal 3r, the reception burst data 4r, the reception data 4o, and the timing signal 50a are the same as those in FIG. 17, the description thereof will be omitted.

The timing management unit 50 measures the phase difference from the UW detection pulse after passing through the aperture and the UW position pulse generated internally, and the estimation unit 600 receives the phase difference information 50b.
As. The estimation unit 600 obtains a frequency deviation existing between the base station and the mobile station with respect to the transmission clock by averaging the phase difference information 50b, and predicts a phase error that may occur in the next reception frame ( This is called a predicted phase error), and the correction information 600a is sent to the timing management unit 50 as necessary. When the correction information 600a is provided, the timing management unit 50 adjusts the reception frame timing by appropriately controlling the internal frame counter. That is, the output of the frame timing signal of the management unit of the local station is controlled based on the correction information 600a, and the transmission / reception data processing unit 4 performs the reception process of the data signal included in the burst signal based on the frame timing signal. .

Next, the communication method in this embodiment will be described with reference to the flowchart of FIG. First, a burst data signal composed of a unique word signal, a data signal, etc. is input (step 1). Next, the unique word detection signal included in the burst data is detected (step 2). The phase difference between the unique word signal and the frame timing signal is detected (step).
3). If the phase difference is not detected, a signal corresponding to the timing at the time of unique word detection is output as a frame timing signal (step 4), and the reception processing of the data signal included in the burst data signal is performed based on this frame timing signal. Perform (step 5).

On the other hand, when the phase difference is detected in the detection result of step 3, the phase difference for the plurality of unique word detection signals is extracted, and the averaging process is performed based on these phase differences (step 6). Then, the frequency deviation existing between the base station and the mobile station is obtained using the averaging processing result (step 7). Based on this frequency deviation, a phase error that will occur in the next received frame is predicted and output (step 8). Then, the timing management unit controls the output of the frame timing signal based on the phase prediction error (step 9). Then, a signal corresponding to the controlled signal is output as a frame timing signal (step 10), and the data signal in the burst data signal is received based on the output-controlled frame timing signal (step 5).

FIG. 3 is a block diagram showing the structure of the timing management unit 50. In FIG. 3, 52 is a frame counter, 53 is a window generator, 54 is a phase difference detector,
50b is the phase difference information, 53b is the UW detection position pulse, and in other cases, the correction information 600a is the frame counter 5
2 is the same as FIG. 18, except that the UW detection pulse 51b after passing through the window is input to the phase difference detector 54. Further, the frame counter 52 and the window generator 53 constitute a signal output means.

The operation of the timing management unit 50 will be described below. The window generator 53 opens the window at a predetermined position based on the counter value of the frame counter 52, and at the same time, generates a UW detection position pulse 53b at the center of the window (timing signal set at a predetermined interval). The generation position of the UW detection position pulse 53b is the UW detection after the window pass of the reception signal that will be received next, if there is no frequency deviation of the transmission clock between the base station and the mobile station and the propagation distance does not change. It coincides with the position of the pulse 51b. In the phase difference detector 54, the UW detection pulse 51b and the UW detection position pulse 53b after passing the window
The phase difference between them is measured. The UW detection pulse 51b is synchronized with the regenerated clock generated by the demodulator, while the UW detection position pulse 53b is synchronized with the clock asynchronously generated with the base station clock internally generated by the mobile station. The phase difference is represented by the lag information and the phase difference amount, and is provided to the estimation unit 600 as the phase difference information 50b.

FIG. 4 shows the relationship between the phase difference and the phase difference information 50b. In Example 1, the UW detection pulse 51b temporally precedes the UW detection position pulse 53b, and A is the phase difference amount. In Example 2, the UW detection position pulse 53b temporally precedes the UW detection pulse 51b, and B is the phase difference amount. In the example 3, the UW detection pulse 51b is placed in the window 53a.
In the case where there are a plurality of pulses, the pulse generated earlier is effective in this case, and as a result, the same pulse as in Example 1 is obtained. When the UW detection pulse 51b is not generated, that is, UW non-detection may occur, it is not directly related to the essence of the present invention, and therefore a detailed description will not be given. Since no burst was received when UW was not detected, the phase difference information 50b is estimated by the estimation unit 6
00 shall not be brought.

FIG. 5 shows the operation of the frame counter 52. The frame counter 52 displays the UW after passing the window.
The control is performed by the detection pulse 51b and the correction information 600a. The initialization by the UW detection pulse 51b after passing through the window is performed at the timing indicated by A, but since the details have been described above, the description will be omitted, and the adjustment by the correction information 600a performed at the timing indicated by B will be described. To do. The correction information 600a instructed by the estimation unit 600 evaluates the phase error between the reception frame timing currently held by the local station and the timing of the burst transmitted by the base station to the local station. This is the phase amount necessary for the station to estimate the timing for the next transmission / reception (frame timing estimation) and to correct the frame timing of the local station to the correct position. At which point in the slot the correction timing B is placed is arbitrary and not so important. What is important is that after the reception frame timing is corrected based on the correction information 600a, the UW detection pulse 51b and the UW detection position pulse 5 are received in the slot to be received next.
3b, the estimation unit 600 outputs the correction information 600a that matches as much as possible, and the timing management unit 5
0 is to modify the received frame timing. Next, details of the estimation unit that generates the correction information 600a will be described.

6 and 7 are diagrams for explaining the operation of the estimation unit 600. FIG. 6 is a diagram for concretely explaining the phase difference reference 50b, that is, the UW detection pulse 5 after passing the window.
It is shown that phase errors d0, d1 and d2 (generally referred to as di) occur between 1b and the UW detection position pulse 53b. This phase difference is brought to the estimation unit 600 in the form of a delayed or advanced identification code + phase difference information 50b to perform frame timing estimation. The mobile station estimates the phase error di (i: 1 to n) to predict a phase error that will occur in the future, and corrects the reception frame timing based on the predicted value.

Next, a method of correcting the received frame timing based on the phase error and the frame timing estimation will be described with reference to FIG. The number of received TDMA frames is used as a basic unit, and the measured value (estimated phase error) di of the phase error generated for each received TDMA frame is indicated by a black circle. In addition, a plurality of measured phase errors di are taken as sample values, and the predicted value of the phase error at the next measurement point (predicted phase error) is shown by a dotted line of linear approximation. The reason for the linear approximation is that the change in the phase error di due to the frequency deviation is considered to change linearly in a short period. The straight line represents the true phase error. In the figure, using the measured phase errors d0 to di as sample values, the predicted phase error dp is obtained from the linear prediction equation, and this is fed back to the frame counter 52 as correction information 600a, and the frame timing is corrected at the point of the received i + 1 frame. Since there is an error due to prediction accuracy between the predicted phase error and the true phase error, this remains as an uncorrected phase error after the frame timing correction.

Here, the above-mentioned linear prediction equation is given by the following equation.

[0067]

[Equation 1]

Although the predicted phase error s changes with time,
a and b are constants. However, actually, a and b are not constant values and change every time a new measurement phase error di is measured. The optimum predicted value s is obtained by calculating a and b from the measured value {di}, the number of times of measurement N and the measurement interval T (TDMA frame length). When the least squares method is used, the approximate straight line is obtained as a value that minimizes the following equation when the deviation of the measured phase error di from the above straight line is represented by Ei.

[0069]

[Equation 2]

The operation of the estimation unit 600 will be supplementarily described with reference to the flowchart of FIG. The flow starts when the burst is received and the phase difference information 50b is input to the estimation unit 600. Now, consider a case where the latest phase difference information 50b, di, is input to the estimation unit 600 in the i-th frame in FIG. In the estimation unit 600, di is the phase difference information 50b.
Is input in burst units (step 601), the phase difference information necessary for obtaining the prediction error straight line is updated to the latest N samples (di-N + 1 to di), and a and b are calculated (step 602). A predicted phase error that occurs from the prediction error straight line to a reception frame timing position that will be received next is obtained and output as correction information 600a to the timing management unit 50 (step 603). According to FIG. 7, the predicted phase error dp generated in the (i + 1) th frame is i
Predict at the time of the frame. Actually, there is an error between the phase deviation based on the prediction and the true phase deviation, and the uncorrected phase error remains even after the correction based on the predicted phase error dp. Therefore, the predictable time has an upper limit. .

In this embodiment, the transmission clock phase error with respect to the base station is measured and evaluated from the UW detection position information. Therefore, even if the UW cannot be received, the reception frame timing to be received next is measured, so that The station reception frame timing can be modified appropriately.

Example 2. Next, another embodiment of the present invention will be described. FIG. 9 is a block diagram showing its configuration.
0 is an estimation unit, 4a is FCS error information, and other signals have the same configuration and function as in FIG. Estimator 700
Generates the correction information 600a from the phase difference information 50b and the FCS error information 4a and supplies it to the timing management unit 50. The operations other than the estimation unit 700 are exactly the same as those in FIG. 1, so the operation will be described below focusing on the estimation unit 700.

The FCS error information 4a is information indicating that the data has an error. This information is estimated by the estimation unit 700.
Therefore, the accuracy of each phase difference information sample is improved by not using the phase difference information 50b of all the received burst signals to derive the prediction error straight line but using only the phase difference information of the burst in which the FCS error does not occur. increase. This operation will be described with reference to the flowchart of FIG. The operation of this flowchart is performed by the timing management unit 50.
And the operation of the estimation unit 700. As in the case of FIG. 8, the flow of FIG. 10 starts in the reception burst cycle, and the FCS error information 4a is input in addition to di as the phase difference information 50b of the i-th frame (step 901). When the FCS error does not occur in the i-th frame (step
902), the prediction error straight line is derived for the latest N samples to determine the a and b values (step 903), and the correction information 600a is output (step 904).

Not all of the phase difference information 50b show correct values. For example, in mobile communication, co-frequency channel interference often occurs because the same frequency is repeatedly used locally in order to effectively use the frequency. When co-frequency channel interference occurs and the level of the interference wave with respect to the desired wave is high, the UW detector may erroneously detect the UW of the interference wave. FIG. 11 shows the UW detection pulse 51b and the UW detection position pulse 53b for the desired wave (A station) and the interference wave (B station).
An example of the relationship with In this case, UW for the interference wave is detected in the j + 2 and j + 3 frames, and the phase difference information 5
Since 0b includes those of the interfering station, as a result, an appropriate prediction error straight line cannot be obtained, resulting in an increase in uncorrected phase error. In order to prevent this, the influence of the interference wave is removed by using the FCS error information and discarding the phase difference information when there is an FCS error. That is, when the means for detecting the interference wave provided in the receiving unit 3 detects the interference, the timing management unit generates the timing signal at a predetermined interval (interval output in the past). Therefore, the estimation unit does not control the operation of the timing management unit.

In general, when there is a code called a color code which is set in the unit of the number of repeating zones, the detection of the interference wave is sure to be performed by the identification by this code, but it does not exist in any system. Not exclusively. Therefore, it is extremely versatile to use the FCS error information that is always inserted in the burst. When receiving an interference wave, UW detection is often an effect, but since it is considered that the possibility of receiving data without error is extremely low in the design of the cell, the identification of the interfering station by FCS error information is essential. It is effective for achieving the purpose.

That is, the phase error is selected according to the FCS error information indicating whether or not there is an error in the received burst data, and an estimation unit for correcting the received frame timing is provided as necessary, so that the evaluation can be performed based on the FCS error information. Since the UW detected position information to be used is selected, the reception frame timing of the own station can be corrected more appropriately.

Example 3. Further, another embodiment of the present invention will be described. FIG. 12 is a block diagram showing the configuration. In FIG. 12, reference numeral 800 is an estimation unit, 3a is received electric field level information, and the others have the same configuration and function as in FIG. The estimation unit 800 generates correction information 600a from the phase difference information 50b and the received electric field level information 3a and supplies it to the timing control unit 50. The operation other than the estimating unit 800 is exactly the same as that in FIG.
The operation will be described focusing on 00.

The received electric field level information 3a is the received signal 3r.
It is given as the average value (or median value) of the reception levels of. Generally, it is obtained by logarithmically compressing the envelope output of the received wave and then detecting the average value, and is used for various purposes such as determining whether or not the mobile station is in the zone area. Since the received electric field level information 3a provides the received electric field level variation information generated by fading or shadowing, the phase difference information 50b can be selected by the received electric field level information 3a.

A sudden decrease in the received electric field level often occurs in mobile communication, and if the line is disconnected each time, a call cannot be established. Therefore, even if the received electric field level falls below a prescribed value, a measure to maintain synchronization is maintained. Is applied. This means that if the viewpoint is changed, the received electric field level may fall below the specified value in the process of collecting the phase difference information 50b. Particularly, in mobile communication such as a cordless telephone system, which is assumed to be moving at low speed, it is considered that the received electric field level may be below a specified value in a plurality of consecutive frames due to low speed fading. Since the phase difference information with respect to the received electric field level below the specified value includes more errors with respect to the true phase deviation, an appropriate prediction error straight line cannot be obtained as a result, resulting in an increase in uncorrected phase error. In order to prevent this, the phase difference information 50b in which the received electric field level is below the specified value is excluded from the prediction error straight line deriving data. That is, when the reception electric field level detection means detects that the reception electric field level is below the specified value, the timing management unit generates the timing signal at a predetermined interval (interval output in the past). The receiving electric field level detecting means is provided in the receiving unit 3.

The operation of the estimation unit 800 will be described with reference to the flowchart of FIG. The flow of FIG. 13 is similar to that of FIG.
Starting at the reception burst cycle, the reception electric field level information 3a is input in addition to di as the phase difference information 50b of the i-th frame (step 1201). Phase difference information 50
Di as b is significant only when the received electric field level of the i-th frame exceeds the specified value (step 1202), and the predicted phase error straight line is derived for the latest N-sample phase difference information (step 1203). The predicted phase error at the time of the next reception is determined from the subsequently calculated predicted phase error line, and the correction information 600
a is output to the timing management unit 50 (step 120).
4). The operation of this flowchart corresponds to the operation of the timing management unit and the estimation unit.

That is, in this embodiment, the phase error is measured from the phase difference between the UW detection pulse and the self-created UW position pulse, and the received frame timing is corrected as necessary while weighting is performed by the received electric field level information. An estimation unit is provided. Therefore, the invalid UW detection position information due to UW erroneous detection can be removed from the measurement value used to correct the self-received frame timing, and the accuracy of the received frame timing estimation can be improved.

Embodiment 4 FIG. Next, another embodiment of the present invention will be described. FIG. 14 is a block diagram showing the configuration. Reference numeral 900 is an estimation unit, 3a is received electric field level information, and the others have the same configuration and function as in FIG. The estimation unit 900 uses the received electric field level information 3a and the FCS error information 4
The correction information 600a is generated from a and the phase difference information 50b, and is provided to the timing management unit 50. The operation other than the estimating unit 900 is exactly the same as that in FIG. 1, and therefore the operation will be described below focusing on the estimating unit 900.

The operation of the estimation unit 900 will be described with reference to the flowchart of FIG. The operation of the flowchart of FIG. 15 corresponds to the operation of the timing management unit and the estimation unit. FIG.
As in the case of FIG. 8, the flow of No. 5 starts in the reception burst cycle, and in addition to di as the phase difference information 50b of the i-th frame, the reception electric field level information 3a and the FCS error information 4
Input a (step 1401). Phase difference information 50b
Di is significant only when the received electric field level of the i-th frame exceeds the specified value and when the FCS error does not occur (step 1402).
A predicted phase error straight line is derived for the phase difference information of the sample (step 1403). The predicted phase error at the time of the next reception is determined from the subsequently calculated prediction position error straight line, and the correction information 600a is output to the timing management unit 50 (step 1404). That is, UW
The phase error is estimated while weighting the detected pulse and FCS error information by the received electric field level information, and the received frame timing is corrected if necessary.

Since the phase difference information in this embodiment is selected by the received electric field level information and the FCS error information, the reliability of the phase difference information is increased.

Although the above description has been made assuming that the phase error is linearly approximated, it goes without saying that when the phase deviation cannot be linearly approximated, another approximating function is used in the estimating unit. Further, when the reception frame timing is corrected (synchronized with the UW detection timing) every time UW is detected, the phase difference information 50b provided to the estimation unit is different from the above, but the correction value is It goes without saying that knowing can accomplish the purpose.

Example 5. Hereinafter, as another embodiment of the present invention, a TDMA communication apparatus for performing handoff at high speed will be described with reference to the drawings. Hereinafter, the handoff means that the communication at the base station becomes difficult for some reason, and the base station is switched to the adjacent base station. The switching may be frequency switching, slot (timing) switching, or both. FIG. 25 is a block diagram showing the configuration of this embodiment. 1000 is a frequency synthesizer, 1001 is a storage unit, 1002 is a control unit, and other parts are the same as those in FIG. 1 except the estimation unit 600. The operation will be described below with reference to FIG.
The operation of the functions other than the frequency synthesizer 1000, the storage unit 1001 and the control unit 1002 is the same as in FIG. Further, in FIG. 1, the frequency synthesizer was not directly necessary for the intended content of the invention, so the description thereof is omitted. However, in this embodiment, the frequency synthesizer 1000 will be described because it is necessary for explaining the operation of the invention.

The frequency synthesizer 1000 includes the control unit 1
002 has a function of switching the frequency according to a frequency switching instruction 1002b. In the present invention, the frequency is switched according to the frequency switching instruction 1002b instructed by the control unit 1002. Frequency switching instruction 1002 in this case
b is a switching instruction to the channel transmitted by the adjacent base station, and is, for example, the frequency of the control channel. Storage unit 1
001 is a frequency switching instruction 1002 from the control unit 1002.
adjacent channel information 1002a brought in synchronization with b
Accordingly, the phase difference between the received frame timing held by the own station and the adjacent base station is stored as the phase difference information 50b.

When channel switching is necessary, the control unit 100
2 is obtained by extracting the necessary phase difference information as correction information 1001a from the phase difference information 50b previously stored in the storage unit 1001 by the adjacent channel selection information 1002c and inputting it to the timing management unit 50. The frame counter 52 is preset to the frame timing of the channel switching destination base station. The selection of the necessary correction information 1001a is output to the storage unit 1001 by the control unit 1002 as the adjacent channel selection information 1002c.

The storage unit 1001 can be constructed by a simple circuit as shown in the block diagram of FIG. In FIG. 26, 250a to 250n are storage elements, and 2501 and 2n.
502 is a switch. Adjacent channel information 1002a
Accordingly, the switch 2501 designates the storage memory element 250x (x = a to n) of the phase difference information 50b. Further, according to the adjacent channel selection information 1002c, the switch 2502
However, the storage element 250x that stores the phase difference information to be output to the timing management unit 50 as the correction information 1001a.
Select (x = a to n). As a result, the reception frame synchronization pull-in can be performed in a short time, and the effect is remarkable especially in the system in which the frame synchronization is not established between the base stations.

Next, referring to FIG. 27, the relationship between the received signal from the adjacent base station and the phase difference information will be described. In FIG. 27, it is assumed that the mobile station is performing intermittent reception with the base station A, and frame synchronization is not established between the base station A and the adjacent base stations B to G. . For example, when viewed from the mobile station, there are delay times corresponding to the phase difference AB and the phase difference AC between the received signal from the base station A and the received signals from the base station B and the base station C, respectively.
When the mobile station hands off from the base station A to the base station B or the base station C in this state, it is necessary to restart the frame synchronization. According to the present invention, since the phase difference AB or the phase difference AC is known at the time of handoff,
Since it is not necessary to resynchronize, the reception frame synchronization can be pulled in in a short time.

The configuration of the storage unit 1001 may be any configuration as long as it has a function of independently storing the phase difference between the adjacent base stations A to G, taking the configuration of FIG. 27 as an example. The function can be realized by a flip-flop or a memory.

Next, the communication method in this embodiment will be described with reference to the flowcharts of FIGS. 28 and 29. 28, under the control of the control unit 1002, the frequency synthesizer 1000 is switched to the frequency of the adjacent base station as necessary (step 10). here,
Switching frequencies is not an essential purpose, but access to adjacent base stations is important. That is, when adjacent base stations set channels at the same frequency and at different timings, it is not necessary to switch frequencies, and desired results can be obtained by switching slot timings, for example. Next, a burst data signal composed of a unique word signal, a data signal and the like transmitted from the adjacent base station is input (step 11), and the control unit 1002
After the adjacent channel information is given to the storage unit 1001 under the control of (step 12), the phase difference measurement routine is called (step 13).

Here, the phase difference measuring routine in step 13 will be described with reference to FIG. The unique word detection signal included in the burst data is detected (step 130), and the phase difference between the unique word signal and the frame timing signal is detected (step 1).
31), when the phase difference is detected, the phase differences for the plurality of unique word detection signals are extracted, and the averaging process is performed based on these phase differences (step 132), and the average value of the phase differences as the averaging process result. Is stored in the storage element designated by the adjacent channel information as a phase error in the next received frame (step 133).

Referring again to FIG. 28, steps 10 to s
Repeat up to step 13 until channel switching becomes necessary. The condition that requires channel switching is not the essence of the present invention, and therefore its explanation is omitted. Further, the access to the receiving base station is not the essence of the present invention, so the description thereof will be omitted. When channel switching, that is, handoff is necessary (step 14), the frequency synthesizer 1000 is switched to the frequency of the adjacent base station by the control of the control unit 1002 (step 15), and the adjacent channel selection information is given to the storage unit 1001 by the control of the control unit 1002. (St
ep16). The timing management unit 50 includes a storage unit 1001.
The output of the frame timing signal is controlled based on the average value of the phase difference output from (step 17).

Example 6. Next, a TDMA communication apparatus that performs handoff at high speed when there is a clock frequency deviation between adjacent base stations will be described. When there is a frequency deviation, the phase difference between the base stations changes momentarily, but when the configuration of the fifth embodiment is applied, the phase difference information 50b is stored in the storage unit 10.
Since it is impossible to hand off at the moment stored in 01, the accuracy of the stored phase information becomes a problem. The purpose of this embodiment is to solve this problem, and its configuration is shown in the block diagram of FIG. This embodiment is shown in FIG.
The estimation unit 600 and the correction information 600a are added, and the control unit 1002 provides the estimation unit 600 with an initialization signal 1002d.

In the present invention, the frequency deviation between the mobile station and the adjacent base station is estimated by the estimation unit 600 for each base station and stored individually, so that the frequency deviation at the time of handoff is absorbed. Therefore, the correction information 60 is stored in the storage unit 1001.
0a is stored, but the principle thereof is the same as that described in the first embodiment, and the description thereof is omitted. At the time of handoff, necessary information is output to the timing management unit 50 as correction information 1001a from the correction information for each adjacent base station stored in the storage unit 1001. The modification information 1001a is the same as the modification information 600a in the sense that it is modification information of a specific base station. In addition, the control unit 1002 to the estimation unit 6
The initialization signal 1002d output to 00 is used to clear the sample value of the phase difference information used for estimation for each adjacent base station.

Next, the communication method in this embodiment will be described with reference to the flowcharts of FIGS. 31 and 32. FIG. 31 shows the phase difference measurement routine (st
ep13) is a frequency deviation estimation routine (step 19)
32, and FIG. 32 shows the frequency deviation estimation routine (step 19). FIG.
In step 1, the unique word detection signal included in the burst data is detected (step 130), the phase difference between the unique word detection signal and the frame timing signal is detected (step 131), and when the phase difference is detected, a plurality of unique words are detected. The phase difference with respect to the detection signal is extracted, and the averaging process is performed based on these phase differences (step 1
32) Then, the frequency deviation existing between the base station and the mobile station is obtained using the averaging processing result (step 134).
Based on this frequency deviation, the phase error that will occur in the next reception frame is predicted, this prediction result is compared with the actual measurement value, and this prediction result is output as correction information (s
Then, the correction information is stored in the storage element designated by the adjacent channel information as the phase error in the next reception frame (step 136). Other operations are the same as those in FIG.

Example 7. Next, a specific method of extracting the phase difference between adjacent base stations as the phase difference information 50b will be described. The block diagram of FIG. 33 shows the configuration of the TDMA communication apparatus in the case where the intermittent non-reception section is used. 50c is intermittent non-reception information, and other components are the same as those in FIG. In FIG. 33, the control unit 1
By inputting the timing indicating the intermittent reception section shown in FIG. 22 by 002 as the intermittent reception information 50c, the transmission signal of the adjacent base station is received using the intermittent non-reception section and the phase difference is measured. The intermittent reception information 50c is the timing shown in the intermittent non-reception section in FIG. This timing can be easily created from the frame counter 52 of FIG.

Example 8. Further, FIG. 34 is a block diagram showing the configuration of the TDMA communication device in the case of using an empty slot as a device for measuring the phase difference not only in the intermittent non-reception section but also in a call. In FIG. 34, 5
0d is empty slot information, and other components are shown in FIG.
Same as 3. The timing management unit 50 provides the intermittent reception information 50c and the empty slot information 50d to the control unit 1002 as timing signals. Empty slot information 50
The timing shown in FIG. 35 can be considered as an example of d. This timing can be easily created from the frame counter 52 like the intermittent reception information 50c.
As a result, the control unit 1002 can perform the phase difference measurement using the empty slot not only during the intermittent reception but also during the call.

Example 9. 3 is a block diagram showing the configuration of a method of using a silent section during a call as a more efficient TDMA communication device as compared with the method of measuring the phase difference between adjacent base stations using an empty slot.
6 will be described. This method utilizes the fact that the voice rate is about 40% in a voice call. In FIG. 36, 40a is a VOX detection signal, 50e is the reception slot information, and the other components are the same as those in FIG. The VOX signal 40a is used when the voice from the base station to the mobile station is silent, that is, when there is no voice signal.
Receive transmission signals from other base stations using that section,
The phase difference 50a is measured. The reception slot information 50e
Is a signal for giving a reception timing, which is the timing shown in FIG.

The operation of this embodiment will be described in more detail with reference to FIG. FIG. 37 shows a state in which a mobile station receives a transmission signal transmitted from a serving base station at regular intervals during a call.
The base station adds a voice detection (V-ON) flag and a silence detection flag (V-OF) to the transmission signal and transmits the signal, and when the signal for the mobile station is in the silence state, the V-OF flag When a voice is detected, a V-ON flag is inserted. Further, after transmitting the V-OF flag insertion signal, the base station shall stop the transmission. As a result, the mobile station
When the F flag is detected, the transmission from the base station is cut off thereafter, so the phase difference measurement is performed by receiving the transmission signal from another base station using the section from V-ON to V-OF (VOX section). I do. Note that, in order to detect the end of the VOX section with high reliability, the silence continuation signal is inserted at a constant period during the VOX section. The silence continuation signal is a silence continuation flag (V
-CT) is added to the transmission signal. As a result, the mobile station can receive the other base station transmission signal with high reliability in the VOX section and the section in which the V-CT flag is not set.

As described above, in the configuration of FIG. 36, it is possible to receive the transmission signal transmitted from the base station in this way and perform the phase difference measurement, and the VOX detection signal 40a is the above three types of flags. These signals bring (V-ON, V-OF, V-CT) to the control unit 1002. By utilizing the silent section, it is possible to measure the phase difference only with the receiving slot without using an empty slot, and therefore the operating time of the mobile station can be shortened, which is effective in saving power.

Example 10. Next, an embodiment of the TDMA communication device in the case of using a low-frequency original vibration during intermittent reception will be described in detail. In the block diagram of FIG. 38, 32
0 is a frequency divider M1, 321 is a frequency divider N1, 322 is a clock timing management unit, 323 is a clock timing estimation unit, 324 is a variable frequency divider M, and the other components are the same as in FIG. The output of the clock generator A221, which is the first clock generation means, is divided by the variable frequency divider M324 and input to the selection circuit 224 as a reception clock signal. The clock generated by the clock generator B225, which is the second clock generation means, is input to the selection circuit 224 as an intermittent clock signal. Selection circuit 224
Selects the input received clock signal or intermittent clock signal as appropriate and outputs it as a clock signal to the outside. Initially, the variable frequency divider M (324) operates as a fixed frequency divider, and the operation up to this point is the same as in FIG.

However, as pointed out as the problem in the conventional example, when clocks having different original frequencies are used, the continuity of the clock signal is changed when the clock signal is switched in the intermittent reception / non-intermittent reception section as shown in FIG. Is damaged. This means that the periodicity of the frame timing stored in the timing management unit 50 is lost, which is a very serious problem in the system. Therefore, in order to smoothly carry out the intermittent reception, it is necessary to prevent the occurrence of phase discontinuity between the reception clock signal and the intermittent reception clock signal. This is the intent of the present invention.

The received clock signal and the intermittent clock signal are divided into the frequency divider M1 (320) and the frequency divider N1 (3), respectively.
It is divided in 21). The outputs of the frequency divider M1 (320) and the frequency divider N1 (321) are the frame signal A32, respectively.
0a and the frame signal B321a, which have the same period. This cycle may be any cycle as long as it is a common multiple of the received clock signal and the intermittent clock signal, and the frequency division ratios M, M1, and N1 may be selected so that this relationship holds.
However, the above relationship is for simplifying the description and is not the essence of the present invention. That is, it goes without saying that the object of the present invention can be achieved even if the cycles are not the same.

The clock timing management section 322 detects the phase difference between the frame signal A320a and the frame signal B321a, and outputs it as the phase difference information 322a to the clock timing estimation section 323. The clock timing estimation unit 323 estimates the phase difference between the clock generator A225 and the clock generator B221 based on the phase difference information 322a, and feeds it back to the variable frequency divider M324. The operations of the clock timing management unit 322 and the clock timing estimation unit 323 are the same as those of the timing management unit 50 and the estimation unit 600 shown in FIG. 1, respectively. This function makes it possible to absorb the frequency deviation between the intermittent clock signal and the received clock signal. When the battery generator has a battery save function, the clock generator A is generally controlled to stop in the intermittent non-reception section. On the other hand, the clock generator B is always operating.

Next, the communication method of this embodiment will be described with reference to FIG.
This will be described using the flowchart of No. 9. In this embodiment,
The frame signal generated from the first clock will be referred to as a frame signal A, and the frame signal generated from the second clock will be referred to as a frame signal B. Since the frame signal can be realized very easily by dividing the frequency of the clock, its explanation is omitted. To simplify the description, the frame signal A
And the frame signal B have the same period. The cycle may be any cycle as long as it is a common multiple of the received clock signal and the intermittent clock signal. However, the above relationship is for simplifying the description and is not the essence of the present invention. That is, it goes without saying that the object of the present invention can be achieved even if the cycles are not the same.

In FIG. 39, the obtained frame signal A
The phase difference between the frame signal B and the frame signal B (step 20
0), averaging processing is performed based on the measured phase differences (step 201), and the frame signal A and the frame signal B are
The frequency deviation existing between and is calculated (step20
2) Predict the frequency deviation that will occur at the timing of the next frame signal B, compare the prediction result with the actual measurement value, and output the prediction result as correction information (step 2).
03), the frequency division ratio of the variable frequency dividing function for generating the frame signal A based on the correction information is adjusted (step 204).
The procedure in FIG. 39 is performed in the cycle of frame A, and the frequency division ratio is adjusted based on the correction information as appropriate.

The continuity of the intermittent clock and the received clock when the clock signal is switched will be described with reference to FIG.
FIG. 40 shows the relationship between the received clock signal and the intermittent clock signal when the mobile station performs the intermittent reception. It is assumed that the mobile station generates a reception clock while receiving a reception signal, and further that the intermittent clock has a frequency of 1/2 of the reception clock. When the intermittent clock and the received clock have a synchronous relationship, as shown in the figure, the rising edges of both clocks are aligned at the beginning of each received signal, and a fixed positional relationship is established. That is, in the example of FIG. 40, the last clock number of each received signal has a relation of I = 2i−1.

However, considering the case where there is a significant frequency deviation between the two clocks due to the difference between the original clocks of the intermittent clock and the received clock, Δ1 and Δ2 are shown at the beginning of the received signal due to the frequency deviation. Phase deviation occurs.
Since this phase deviation directly causes the reception position for receiving the reception signal to be deviated, the clock timing management unit 322 measures the phase error (step 200), and the clock timing estimation unit 323 measures the frequency deviation between both clocks. Is estimated (steps 201 to 203), and the phase difference Δ1 and Δ2 is absorbed by the variable frequency divider M324 (step 204) to maintain the synchronization relationship.

[0111]

Since the present invention is constructed as described above, it has the following effects.

The output timing of the frame timing signal is estimated from the frequency deviation between the frame timing signal of the base station and the slave station, and the output of the frame timing signal of the slave station is controlled based on the estimation result. It can be received with the configuration and accurately.

Since the output of the frame timing signal of the slave station is controlled on the basis of the error information when the interference wave is detected and the above estimation result, the received data can be received more accurately.

Since the output of the frame timing signal of the slave station is controlled based on the received electric field level information and the above estimation result, the received data can be received more accurately.

Since the output of the frame timing signal of the slave station is controlled on the basis of the received electric field level information, the error information when the interference wave is detected, and the above estimation result, the received data can be received more accurately. You can

Since the transmission signal from another base station is received and the phase difference from the frame timing held by the own station is measured and stored, the switching time at the time of inter-cell handoff can be shortened.

In addition, when a transmission signal from another base station is received,
Since the phase difference from the frame timing held by the own station is measured and the frequency deviation is estimated from the result and stored, the switching time at the time of inter-cell handoff can be further shortened.

Since the phase difference measurement is performed in advance by using the standby time, the handoff time can be shortened.

Furthermore, by performing the phase difference measurement using the empty slot during the call, the handoff during the call can be performed at high speed.

Further, by performing the phase difference measurement using the silent section of the signal from the base station to the mobile station, the handoff during the call can be performed at high speed.

Further, even if there is a frequency deviation between the reception clock and the intermittent clock, the frequency deviation is estimated and corrected, so that the frame timing error can be reduced during the intermittent reception.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a first embodiment of the present invention.

FIG. 2 is a flowchart illustrating the operation of the first exemplary embodiment of the present invention.

FIG. 3 is a block diagram showing a configuration of a timing management unit according to the first exemplary embodiment of the present invention.

FIG. 4 is a diagram illustrating a relationship between a phase difference and phase difference information according to the first embodiment of the present invention.

FIG. 5 is a diagram illustrating an operation of the frame counter according to the first embodiment of the present invention.

FIG. 6 is a diagram illustrating an operation of an estimation unit according to the first embodiment of the present invention.

FIG. 7 is a diagram illustrating an operation of the estimation unit according to the first embodiment of the present invention.

FIG. 8 is a flowchart illustrating an operation of the estimation unit according to the first embodiment of the present invention.

FIG. 9 is a block diagram showing a configuration of a second embodiment of the present invention.

FIG. 10 is a flowchart illustrating the operation of the second embodiment of the present invention.

FIG. 11 is a diagram illustrating the influence of co-channel interference in the second embodiment of the present invention.

FIG. 12 is a block diagram showing a configuration of a third embodiment of the present invention.

FIG. 13 is a flowchart illustrating an operation of the estimation unit according to the third exemplary embodiment of the present invention.

FIG. 14 is a block diagram showing a configuration of a fourth embodiment of the present invention.

FIG. 15 is a flowchart illustrating an operation of the estimation unit according to the fourth exemplary embodiment of the present invention.

FIG. 16 is a diagram illustrating the concept of TDMA.

FIG. 17 is a block diagram showing a configuration of a conventional mobile station.

FIG. 18 is a block diagram showing a configuration of a conventional timing management unit.

FIG. 19 is a diagram illustrating an operation of a conventional timing management unit in time series.

FIG. 20 is a diagram illustrating a conventional handoff operation.

FIG. 21 is a diagram illustrating a conventional handoff algorithm.

FIG. 22 is a diagram illustrating a conventional clock switching operation during intermittent reception.

FIG. 23 is a block diagram for generating a conventional received clock and an intermittent clock.

FIG. 24 is a block diagram for generating a conventional received clock and an intermittent clock.

FIG. 25 is a block diagram showing a configuration of a fifth embodiment of the present invention.

FIG. 26 is a block diagram showing a configuration of a storage unit of the present invention.

[Fig. 27] Fig. 27 is a diagram for explaining the relationship between a received signal from an adjacent base station and phase difference information.

FIG. 28 is a flowchart illustrating the operation of the fifth embodiment of the present invention.

FIG. 29 is a flowchart illustrating the operation of the fifth embodiment of the present invention.

FIG. 30 is a block diagram showing a configuration of a sixth embodiment of the present invention.

FIG. 31 is a flowchart illustrating the operation of the sixth embodiment of the present invention.

FIG. 32 is a flowchart illustrating an operation of the sixth embodiment of the present invention.

FIG. 33 is a block diagram showing a configuration of a seventh embodiment of the present invention.

FIG. 34 is a block diagram showing a configuration of an eighth embodiment of the present invention.

FIG. 35 is a diagram for explaining empty slot information and the reception slot information.

FIG. 36 is a block diagram showing a configuration of a ninth embodiment of the present invention.

FIG. 37 is a diagram for explaining the operation of the ninth embodiment of the present invention.

FIG. 38 is a block diagram showing the structure of the tenth embodiment of the present invention.

FIG. 39 is a flowchart illustrating the operation of the tenth embodiment of the present invention.

FIG. 40 is a diagram for explaining the operation of the tenth embodiment of the present invention.

[Explanation of symbols]

2 transmitter, 3 receiver, 3a received electric field level information,
4 transmission / reception data processing unit, 4a FCS error information, 4
0a VOX detection signal, 50 timing management unit, 50
a timing signal, 50b phase difference information, 50c intermittent non-reception information, 50d empty slot information, 50e relevant reception slot information, 51 UW detector, 52 frame counter, 53 window generator, 53b UW detection position pulse, 54 phase difference detection Vessel, 121 mobile station, 1
23a, 123b Base station, 221 Clock generator A, 224 selection circuit, 225 Clock generator B, 3
20 frequency divider M1, 320a Frame signal A, 321
Frequency divider N1, 321a Frame signal B, 322 Clock timing management section, 322a Phase difference information, 323
Clock timing estimation unit, 323a Feedback signal, 324 Variable frequency divider M, 600, 700, 80
0,900 estimation unit, 600a correction information, 1000
Frequency synthesizer, 1001 storage unit, 1001a
Correction information, 1002 control unit, 1002a adjacent channel information, 1002b frequency switching instruction, 1002c
Adjacent channel switching information.

Claims (17)

[Claims] 1. A TDMA communication device for performing time-division communication between a base station and a slave station other than this base station using a frame allocated in a predetermined time width for each slave station, wherein the slave station is a predetermined Timing signal output means for outputting a timing signal at a timing; detection means for detecting a unique word (UW) included in a received signal from the base station and outputting a UW detection signal; and output by the timing signal output means. Phase difference detecting means for detecting a phase difference between the timing signal and the UW detection signal output from the detecting means, and based on the phase difference detected by the phase difference detecting means, the base station and the slave station The frequency deviation of the timing signal existing between them is obtained, and based on this frequency deviation, the tie existing between the base station and the slave station in the next receiving frame is calculated. Based on the timing signal output from the timing signal output means and corrected by the correction information that is output from the timing signal output means and that estimates the phase error of the ringing signal and notifies the timing signal output means as the correction information. A TDMA communication device, comprising: a processing unit that performs a reception process of a received signal from the base station. 2. A TDMA communication method for performing time-division communication between a base station and a slave station other than this base station by using a frame allocated in a predetermined time width for each slave station, wherein the slave station is the base station. A first step of detecting a unique word (UW) included in a reception signal from the station and outputting a UW detection signal; a timing signal output from a timing signal output means included in the slave station; A second step of detecting a phase difference from the UW detection signal output in the step, and a timing signal existing between the base station and the slave station based on the phase difference detected in the second step. Based on the frequency deviation obtained in the third step and the frequency deviation obtained in this third step,
A fourth step of estimating the phase error of the timing signal existing between the base station and the slave station in the next reception frame and outputting it as correction information, and the correction information output in this fourth step. A fifth step of correcting the timing signal of the timing signal output means based on the above, and a sixth step of performing a receiving process of the received signal from the base station based on the timing signal corrected in the fifth step. And a TDMA communication method. 3. The phase difference detecting means includes U corresponding to the timing signal output from the timing signal output means and the plurality of frames output from the detecting means.
The plurality of phase differences from the W detection signal are detected, the estimation unit derives a prediction formula based on the plurality of phase differences, and predicts the phase error from the prediction formula. The TDMA communication device according to item 1. 4. The processing unit outputs error information to the estimation unit when the slave station receives an interference wave, and the estimation unit obtains the frequency deviation based on the error information and the phase difference. The TDMA communication device according to claim 1, wherein 5. The first step detects a unique word (UW) included in a received signal from the base station, outputs a UW detection signal, and outputs error information when an interference wave is received. And the third step is present between the base station and the slave station based on the error information output in the first step and the phase difference detected in the second step. The TDMA communication method according to claim 2, wherein the frequency deviation of the timing signal is obtained. 6. The reception electric field level detecting means for detecting the electric field level received by the slave station and outputting the reception electric field level information to the estimation unit, wherein the estimation unit is based on the reception electric field level information and the phase difference. The TDMA communication device according to claim 1, wherein the frequency deviation is obtained. 7. The first step detects a unique word (UW) included in a reception signal from the base station, outputs a UW detection signal, and outputs reception electric field level information. The step of is based on the received electric field level information output in the first step and the phase difference detected in the second step, and the frequency deviation of the timing signal existing between the base station and the slave station. 3. The TDMA communication method according to claim 2, wherein 8. The slave station comprises a received electric field level detecting means for detecting a received electric field level and outputting the received electric field level information to the estimating section, and when the slave station receives an interference wave, the processing section The TDMA according to claim 1, wherein the error information is output to the estimation unit, and the estimation unit obtains the frequency deviation based on the received electric field level information, the error information and the phase difference. Communication device. 9. The first step detects a unique word (UW) included in a received signal from the base station, outputs a UW detection signal, and outputs error information when an interference wave is received. And a received electric field level information, the third step is based on the error information output in the first step, the received electric field level information and the phase difference detected in the second step, and the base station 3. The TDMA communication method according to claim 2, wherein the frequency deviation of the timing signal existing between the station and the slave station is obtained. 10. A TDMA communication device for performing time-division communication between a base station and a mobile station using a frame assigned to each mobile station in a predetermined time width, wherein the mobile station transmits and receives frequencies. A frequency synthesizer for switching, timing signal output means for outputting a timing signal at a predetermined timing, detection means for detecting a unique word (UW) included in a received signal from the base station, and outputting a UW detection signal, Phase difference detection means for detecting the phase difference between the timing signal output from the timing signal output means and the UW detection signal output from the detection means, and the phase difference detected by the phase difference detection means for each base station. Storage means for storing each, and at the time of handoff, gives an instruction to switch the frequency of transmission and reception to the frequency synthesizer and Control unit for notifying the timing signal output unit of the phase difference with the switching destination base station stored in the stage, and timing corrected by the phase difference output from the timing signal output unit and notified by the control unit. A TDMA communication device, comprising: a processing unit that performs a reception process of a reception signal from the base station based on a signal. 11. A TDMA communication method for performing time-division communication between a base station and a mobile station using frames allocated to each mobile station with a predetermined time width, wherein the mobile station is First step of detecting a unique word (UW) included in the received signal and outputting a UW detection signal; a timing signal output from a timing signal output means included in the mobile station; A second step of detecting a phase difference from the UW detection signal output in the step, a third step of storing the phase difference detected in the second step in a storage unit, and the first to third steps described above. The above steps are repeated for each of the above base stations, the fifth step of switching the transmission / reception frequency corresponding to the switching destination base station at the time of handoff, and the third step described above. A sixth step of notifying the timing signal output means of the stored phase difference from the switching destination base station, and the timing signal of the timing signal output means based on the phase difference notified in the sixth step. And a eighth step of performing reception processing of a reception signal from the base station of the switching destination based on the timing signal corrected in the seventh step. TDM
A communication method. 12. A TDMA communication apparatus for performing time-division communication between a base station and a mobile station using a frame allocated to each mobile station in a predetermined time width, wherein the mobile station transmits / receives frequencies. A frequency synthesizer for switching, timing signal output means for outputting a timing signal at a predetermined timing, detection means for detecting a unique word (UW) included in a received signal from the base station, and outputting a UW detection signal, Phase difference detecting means for detecting a phase difference between the timing signal output from the timing signal outputting means and the UW detection signal output from the detecting means; and based on the phase difference detected by the phase difference detecting means, Obtain the frequency deviation of the timing signal existing between the base station and the mobile station, based on this frequency deviation, in the next reception frame An estimation unit that predicts a phase error of a timing signal existing between the base station and the mobile station and outputs it as correction information, and a storage unit that stores the correction information output by this estimation unit for each base station. , A controller for giving an instruction to switch the frequency of transmission and reception to the frequency synthesizer at the time of handoff, and notifying the timing signal output means of correction information corresponding to the switching destination base station stored in the storage means; A TDMA communication comprising: a processing unit for receiving a reception signal from the base station based on the timing signal output from the signal output unit and corrected by the correction information notified by the control unit. apparatus. 13. A TDMA communication method for performing time-division communication between a base station and a mobile station using frames allocated to each mobile station in a predetermined time width, wherein the mobile station is First step of detecting a unique word (UW) included in the received signal and outputting a UW detection signal; a timing signal output from a timing signal output means included in the mobile station; A second step of detecting a phase difference from the UW detection signal output in the step, and a timing signal existing between the base station and the mobile station based on the phase difference detected in the second step Based on the frequency deviation obtained in the third step and the frequency deviation obtained in this third step,
A fourth step of estimating the phase error of the timing signal existing between the base station and the mobile station in the next reception frame and outputting it as correction information, and the correction output in this fourth step. A fifth step of storing information, a sixth step of repeating the above first to fifth steps for each base station, and a seventh step of switching the transmission / reception frequency corresponding to the switching destination base station during handoff. Based on the correction information notified in the eighth step, and the eighth step of notifying the timing signal output means of the modification information of the switching destination base station stored in the fifth step. A ninth step of modifying the timing signal of the timing signal output means, and the switching destination of the switching destination based on the timing signal modified in the ninth step. TD, characterized in that a tenth step of performing a reception processing of the received signal from the earth station
MA communication method. 14. The phase difference detection means utilizes the intermittent non-reception section to output the timing signal output from the timing signal output means and the UW detection signal output from the detection means from an adjacent base station. 13. The TDM according to claim 10 or 12, wherein the phase difference of
A communication device. 15. The phase difference detection means utilizes the empty slot of the frame to detect the timing signal output from the timing signal output means and the UW detection from the base station output from the detection means. 13. The TDMA communication device according to claim 10 or 12, wherein a phase difference from a signal is detected. 16. The phase difference detection means utilizes the silent section to determine the position of the timing signal output from the timing signal output means and the UW detection signal from the adjacent base station output from the detection means. 13. The TDMA communication device according to claim 10 or 12, wherein a phase difference is detected. 17. The timing signal output means includes first clock generating means for generating a reception clock signal, second clock generating means for generating an intermittent clock signal, and the first clock generating means. Variable frequency dividing means for dividing the output to generate the received clock signal, selecting means for selecting the generated received clock signal or the intermittent clock signal, and first dividing the output of the variable frequency dividing means Frequency dividing means, second frequency dividing means for dividing the output of the second clock generating means, and clock timing managing means for measuring the phase difference between the outputs of the first and second frequency dividing means. The frequency deviation of the received clock signal and the intermittent clock signal is estimated based on the measured phase difference, and the period of the intermittent clock signal is received based on the estimation result. Claim paragraph 1, characterized in that a clock timing estimation means for controlling said variable frequency divider means such that the common multiple of the period of the clock signal, paragraph 10, 12
Item 11. The TDMA communication device according to any one of items.