JP2002111547A - Mobile receiving terminal - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To add value to a reproduction system using a multipath analysis result in receiving a CDM transmission signal. SOLUTION: An ambient environment determining unit 31 determines an ambient environment stepwise from the number of paths in a CDM reception signal obtained by a path search unit 18. The determination result of the surrounding environment determination unit 31 is sent to the equalizer screen display selector 32. The selector 32 selects a predetermined equalizer display pattern from the memory 33 in which the equalizer display patterns A to D are registered according to the level value of the surrounding environment determination result, and sends the selected equalizer display pattern to the graphic equalizer 34. The graphic equalizer 34 receives an audio signal to be reproduced by ACC and displays a result of frequency analysis of the audio signal according to a pattern from the selector 32.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mobile receiving terminal device for receiving a transmission signal by a CDM (Code Division Multiplexing) modulation system.

[0002]

2. Description of the Related Art Hitherto, development of a digital broadcasting system for a mobile object using a CDM modulation scheme has been advanced. The CDM modulation method has an advantage of being resistant to multipath, because even if there are some multipaths, each path can be analyzed and RAKE-combined to increase the reception sensitivity. Here, in the development of the above system, one of the issues is to add a value to the reproduction system by utilizing processing unique to the CDM modulation system.

[0003]

As described above, the CDM
As a mobile reception terminal device used in a transmission system using a modulation system, it is mentioned as one problem that a process unique to the CDM modulation system is utilized to add value to a reproduction system.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a mobile receiving terminal device which adds a value to a reproducing system by using a multipath analysis result in receiving a CDM transmission signal. Aim.

[0005]

In order to achieve the above object, the present invention has the following characteristic configuration.

(1) In a mobile receiving terminal device for receiving a transmission signal by a CDM (Code Division Multiplexing) modulation method, a radio wave state identification means for identifying a change in a radio wave state by a path search of the reception signal, and at least the reception signal Reproduction means for reproducing the demodulated output of the reproduction means, and reproduction system control means for changing a reproduction output of the reproduction means or an additional reproduction output linked to the reproduction output in accordance with the identification result of the radio wave state identification means. It is characterized by doing.

(2) In the configuration of (1), the radio wave state identifying means identifies the change in the radio wave state from at least one of the number of paths, received power intensity, and delay amount obtained by the path search. Features.

(3) The configuration of (2) is further characterized by further comprising a reception sensitivity display means for displaying the reception power intensity of the path obtained by the radio wave state identification means as reception sensitivity information.

(4) In the configuration of (3), the reception sensitivity display means displays the total sum of the received power including multi-paths by adding or subtracting the sum of the number of paths.

(5) In the configuration of (1), the reproduction means includes a spectrum analyzer for analyzing and displaying a frequency spectrum of the reproduction output, and the reproduction system control means determines whether or not the radio wave state identification means has received the identification result. The display color or display format of the spectrum analyzer is changed accordingly.

(6) In the configuration of (1), the reproducing means includes an image display means, and the reproduction system control means controls the background displayed on the image display means in accordance with the identification result of the radio wave state identifying means. It is characterized by changing an image.

(7) In the configuration of (6), when the map is displayed on the image display means, the reproduction system control means is displayed on the image display means in accordance with the identification result of the radio wave state identification means. The scale of the map to be changed is changed.

(8) In the configuration of (1), when the transmission signal is composed of a plurality of channels and different information is transmitted in each channel, the reproducing means has a channel selecting means, and the reproducing system controlling means has And selecting a channel according to the identification result of the radio wave condition identification means through the channel selection means.

[0014]

Embodiments of the present invention will be described below in detail with reference to the drawings.

First, the point of view of the present invention will be described.

As described above, the CDM modulation method is a technique for obtaining a stronger radio wave by analyzing and adding multipath waves. Therefore, when analyzing a multipath wave, there is a path search means for analyzing and outputting the relative position, strength, and number of multipaths.

Here, a multipath is a reflected wave, and the fact that there are many reflections is an environment in which many buildings exist in the vicinity in many cases, and conversely, if there is little reflection, it is an environment in which there are many fields. Often. Generally, it can be said that the environment with many buildings is an urban area and the environment with few buildings is a suburban area (this is referred to as an ambient environment here). From this,
By obtaining the number and strength of multipaths, it is possible to predict the surrounding environment.

Therefore, in the present invention, various aspects have been focused on adding the added value by grasping the surrounding environment by using the multi-pass analysis result obtained by the path search and performing reproduction processing suitable for the environment. Provides playback processing.

FIG. 1 is a block diagram showing a basic configuration of a mobile receiving terminal device used in a digital broadcasting system for mobile objects to which the present invention is applied. The broadcast wave is obtained by multiplexing and orthogonally modulating program information distributed to a plurality of channels (here, three channels) together with a pilot channel signal for synchronization control by CDM modulation. When the antenna 11 receives this broadcast wave, The output is frequency-converted by the front end 12 and quadrature-demodulated to become an I signal and a Q signal.
Supplied to

In the propagation analysis unit 13, the waveforms of the I signal and the Q signal are shaped by the roll-off filter 131, and the timing is adjusted by the signal delay circuit 132 to adjust the pilot channel, the first broadcast channel, the second broadcast channel, and the third The data is output to the reception processing units 14 to 17 of the broadcast channel. The output of the roll-off filter 131 is AGC (automatic gain control)
The signal is supplied to the AGC control of the front end 12 through the processing circuit 133 and is supplied to the matched filter 134. The matched filter 134 calculates the correlation between the input signal and the pseudo random sequence, and the result of the correlation is supplied to the path search unit 18.

The path search section 18 analyzes the position, number, strength, etc. of the paths on the time axis from the correlation result obtained by the matched filter 134, and the analysis result is supplied to the demodulation control section 19. You. The demodulation control section 19 executes a demodulation process of a selected channel based on a path search analysis result.

The reception processing unit 14 for the pilot channel
Takes the I signal and the Q signal from the propagation analysis unit 13, despreads each path by a plurality of despreading circuits 141, expands them on the frequency axis, and superimposes them synchronously by a rake combining circuit 142, and After performing error correction decoding in the decoding circuit 143 and deinterleaving in byte units in the byte deinterleaving circuit 144, control data is obtained in an RS (Reed-Solomon) decoding circuit 145.

The reception processing units 15 to 17 for the first to third channels have the same configuration.
, And despread for each path by a plurality of despreading circuits 151, 161, and 171 to develop on the frequency axis, and rake combining circuits 152, 162, and 17
5 are superimposed in synchronization with each other, deinterleaved in bit units by bit deinterleaving circuits 153, 163 and 173, and Viterbi decoding circuits 154, 164, 1
74 performs error correction decoding, and byte deinterleave circuit 1
After deinterleaving in byte units at 55, 165 and 166, the RS (Reed-Solomon) decoding circuit 15
At 6,166,176, the program information data of the channel is acquired.

The first to third channel reception processing units 1
The outputs 5 to 17 are multiplexed by the multiplexing unit 20 and supplied to the reproduction processing unit 21. The reproduction processing unit 21 transmits the program information data from the multiplexing unit 20 to a distribution circuit (DEMUX) 2.
11 to input video data to an MPEG-4 decoder 2
12, the audio data is distributed to the AAC decoder 213, the data broadcast data is distributed to the data broadcast decoder 214,
Each of the decoders 212 to 214 reproduces a video (video) signal of a broadcast program, an AAC audio (sound) signal, and a data broadcast signal. The video signal and the data broadcast signal are sent to a display device, and the audio signal is sent to an audio playback device.

An embodiment of the value-added content provided by the mobile receiving terminal device according to the present invention will be described.

In the embodiment of FIG. 2, (1) switching of the pattern of the graphic equalizer display based on the surrounding environment judgment, (2) switching of the background screen at the time of sound or data broadcasting, and (3) reception sensitivity display by the radio field strength judgment. Three applications are shown.

First, the surrounding environment determination unit 31 determines the surrounding environment from the number of paths obtained by the path search unit 18.
FIG. 5 shows a flowchart of this determination method. In FIG. 5, when the surrounding environment determination is started, first, the number of passes for 5 seconds is input from the path search unit 18 and an average value is calculated (S11). Subsequently, if the average number of passes P is P ≦ 4, 4 <
It is determined to which of P ≦ 8 and 8 <P ≦ 12 it belongs (S12 to S14), and levels 1 to 3 are determined according to the belonging range.
(S15-S17), and if it does not belong to any range, it is set to level 4 (S18), and a four-stage determination result is obtained.

That is, in the above-mentioned surrounding environment judgment method, the number of multipaths is divided into four stages assuming that the maximum number is 12, and the level is set. In general, when the number of multipaths is small, it is considered to be a suburb, and when it is large, it is a city. Therefore, in this example, level 1 is the most suburban and level 4 is the most urban. In this determination, using the number of multipaths in real time as it is has variations and has a problem.
The average of the number of seconds is averaged.

The switching of the graphic equalizer display pattern using the surrounding environment judgment result will be described.

In FIG. 2, the judgment result of the surrounding environment judgment section 31 is sent to the equalizer screen display selector 32. The selector 32 selects a predetermined equalizer display pattern from a memory (generally using a ROM) 33 in which four equalizer display patterns A to D are registered in advance according to the level value of the surrounding environment determination result, Send to graphic equalizer 34. This graphic equalizer 34
The audio signal reproduced by the ACC decoder 213 shown in FIG. 1 is input, and the frequency analysis result of the audio signal is displayed according to the pattern from the selector 32. As the equalizer display pattern, a display color, a display format (bar display, character display, Bezier display, and the like) can be considered, and the like.
A pattern matching the image of the suburbs and urban areas is selected from the level judgment values. This selection may be arbitrarily set by the user.

FIG. 6 shows an example of a processing flow in the display selector 33. In FIG. 6, when the mode is set to the equalizer display pattern switching mode, the four-stage determination result is input from the surrounding environment determination unit 31 (S21), and it is determined which level value belongs to 1 to 3 (S22). ~ S2
4) In the case of level 1, pattern A is selected (S2
5) In the case of level 2, pattern B is selected (S2
6) In the case of level 3, pattern C is selected (S2
7) If not belonging to any of the values, the pattern D is selected (S28). The above processing is repeated.

Next, switching of a voice or data broadcast background screen using the result of the surrounding environment determination will be described.

In FIG. 2, the judgment result of the surrounding environment judgment section 31 is sent to the background screen display selector 35. The selector 35 selects a predetermined background display pattern from a memory (generally using a ROM) 36 in which four background display patterns A to D are registered in advance according to the level value of the surrounding environment determination result. It is sent to the display device 37. This display device 3
Reference numeral 7 inputs a data broadcast signal reproduced by the data broadcast decoder 214 shown in FIG. 1, switches the background image according to the background display pattern from the selector 35, and displays characters and characters of the data broadcast. Examples of the background display pattern include a still image, a color, a Bezier, a line art, a Lissajous waveform, and the like. If there is no data broadcast,
Only the background display may be used.

That is, since nothing is displayed on the display portion in the broadcast of only audio, it is common to display a still image such as a photograph or a picture. Be taken. In contrast,
In the present invention, four patterns registered in advance are switched according to the surrounding environment determination result. This makes it possible to automatically switch to an image suitable for an urban area in an urban area and an image suitable for a suburban area in a suburban area. The processing of the display selector 35 in this case is as follows.
The processing flow shown in FIG. 5 can be applied as it is. Further, in this embodiment, when there is a data broadcast, the background screen can be switched in accordance with the surrounding environment while displaying the data broadcast.

Incidentally, a sensor for distinguishing between day and night and a sensor for detecting rainfall (for example, an on-off switch of a small lamp, an automatic lighting device of a headlight, an on-off switch of a wiper, a raindrop sensor for a wiper, etc. can be used in an automobile). If this is combined with the detection result, a display more suitable for the environment can be performed.

Next, a description will be given of the display of the reception sensitivity based on the radio wave intensity judgment.

In FIG. 2, the radio wave intensity judging unit 38 receives information on the strength (power intensity) of each path from the path searching unit 18,
At this stage, the received radio wave intensity is determined. The stepwise intensity determination result is converted into reception sensitivity corresponding to the power intensity by the reception sensitivity display processing unit 39, sent to the level meter 40 or the numerical display 41, and displayed.

FIG. 7 shows an example of the processing flow of the radio wave intensity judging section 38. In FIG. 7, when reception starts,
The I and Q power information of the path detected from the path search unit 18 is received, and the respective powers are calculated (P ₀ = I ² +
Q ² ) to obtain a sum (Ps = ΣPn (n = 0, 1,...)) (S31). Subsequently, the surrounding environment determination units 31 to 4
The determination result of the stage is input (S32), and it is determined whether the level is one of 1 to 3 (S33 to S35). Here, when the level is 1, it is determined that the power is P = Ps (S3).
6) In the case of level 2, the power is determined to be P = Ps / 2 (S37), and in the case of level 3, the power is P = Ps
/ 3 (S38), and when the level is not any level, that is, in the case of level 4, the power is P = Ps /
The range is 4 (S39).

The present embodiment aims at displaying the intensity of radio waves. As described in the above processing flow, since the power of each multipath is given by P ₀ = I ² + Q ² , the received power at that time can be determined by taking the sum of the multipath powers. In the conventional CDM receiving terminal, the sum of the power is used as it is for display.
It is not necessarily the reception sensitivity itself. This is because multi-paths outside the combined detection range or low-level multi-paths interfere and lower the actual reception sensitivity.

Since such a situation is likely to occur when there are many multipaths, in the present embodiment, the display power is adjusted according to the determination level value using the determination level obtained by the surrounding environment determination unit 31. I have. That is, the higher the level obtained by the surrounding environment determination unit 31 (the more multipaths), the more
The reception sensitivity is lowered, and the display is performed with the electric power reduced to 1/4 in the urban area where the level finally becomes 4.

As a display method of the reception sensitivity, a level display or a numerical display can be considered. Since these display processes are known, their description is omitted.

Next, an embodiment in which the map display of the car navigation device is linked to the surrounding environment judgment result will be described with reference to FIGS. In FIG. 3, the same parts as those in FIG. 2 are denoted by the same reference numerals, and description thereof will be omitted.

In the embodiment shown in FIG.
Is input to the narrow area / wide area command generation unit 42,
A narrow area command or a wide area command is generated in accordance with the level of the surrounding environment determination result, and the display magnification of the display 43 of the car navigation device is controlled.

FIG. 8 shows a processing flow of the narrow area / wide area command generation section 42. In FIG. 8, when interlocking with the car navigation device is started, a judgment result is input from the surrounding environment judgment unit 31 (S41), and the judgment result is 1, 2, 3
Is determined (S42 to S44). When the judgment level is 1 or 2, a wide area command is generated (S45, S45).
46) If the judgment level is 3, or if it is not one of 1, 2, and 3 (level 4), a narrow area command is generated (S47, S48).

That is, in a suburb, generally, high-speed movement is performed and the road is simple, so that a wide area map is displayed. Conversely, in an urban area, the movement is slow and the road is complicated, so that the road is complicated. It is desirable to display a regional map. In the conventional car navigation device, the switching is performed by the user.

In the present embodiment, since the surrounding environment judging section 31 judges whether the area is a suburb or an urban area based on the level, the selection of the map of the car navigation device is automatically switched using this.

As a method, when the level of the surrounding environment determination is low, the multipath is small and it can be determined that the area is a suburb.
Display a wide area map. Also, when the level of the surrounding environment determination is large, there are many multipaths, and it can be determined that the area is an urban area.
Display a narrow area map.

Next, with reference to FIGS. 4 and 9, an embodiment in which the channel selection is linked to the surrounding environment judgment result will be described. In FIG. 4, the same parts as those in FIG. 2 are denoted by the same reference numerals, and description thereof will be omitted.

In the embodiment shown in FIG.
Is input to the channel selection unit 44. The channel selection unit 44 captures EPG (Electronic Program Guide) data transmitted from a broadcasting station through the digital broadcast receiving device 45 to grasp the program contents, and based on the surrounding environment determination result, for suburban and urban areas. Is selected, and the selected channel is designated to the digital broadcast receiving device 45.

FIG. 9 shows a processing flow of the channel selector 44. In FIG. 9, when the automatic channel selection mode is set, the determination result is input from the surrounding environment determination unit 31 (S
51), it is determined whether the determination result is any one of 1, 2, and 3 (S52 to S54). When the judgment level is 1 or 2, the channel is changed to a suburban channel (S55, S56). When the judgment level is 3, or when neither of 1, 2, and 3 (level 4), the channel for an urban area is used. (S57, S58).

With the above processing, it is possible to automatically switch and reproduce a program according to the surrounding environment.

Here, if genre codes specifying suburban and urban areas are added to the broadcast station side as EPG data, the channel selecting section 44 searches the genre codes to search for suburban and urban areas. It is possible to easily detect and select a program for an urban area. Also, EP
The G data is not limited to broadcasting, but can be obtained from a predetermined provider through a wireless telephone. In this case, a genre code for designating a suburban area or an urban area may be added on the provider side.

In an urban area, it is also considered to multiplex commercial broadcasts of shops and the like by using a repeater such as a gap filler. Therefore, it is convenient for the user if the user can select a mode for automatically switching to the commercial broadcast channel when entering a city area.

From the above, in each of the above embodiments,
By determining the number of multipaths, the surrounding environment can be determined stepwise, and using this result, an additional service can be realized in the reproduction system. Also,
In the display of the reception sensitivity, the display can be performed in consideration of the surrounding environment, so that the display of the reception sensitivity can be performed more accurately than the general method based on the total power of each path.

In the above embodiment, the case where the surrounding environment is determined from the number of paths has been described.
The surrounding environment can also be determined from the delay amount of the path obtained in step S8. For example, when the delay amount of the path is large, it can be determined that a mountain continues in the vicinity. When the delay amount gradually decreases, it can be determined that the vehicle is approaching the mountain, and when the delay amount gradually increases, it can be determined that the vehicle is far from the mountain. By such a determination, urban areas,
The same application can be realized not only in the suburbs but also in relation to the mountains.

[0056]

As described above, according to the present invention, it is possible to provide a mobile receiving terminal apparatus which adds a value to a reproducing system by utilizing a multipath analysis result in receiving a CDM transmission signal.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a basic configuration of a mobile receiving terminal device used in a digital broadcasting system for mobile objects to which the present invention is applied.

FIG. 2 is a block diagram showing a configuration of a graphic equalizer display pattern switching based on a surrounding environment determination, a background screen switching during audio or data broadcasting, and a reception sensitivity display based on a radio field strength determination as an embodiment of the present invention.

FIG. 3 is a block diagram showing a configuration in which a map display of a car navigation device is linked to a surrounding environment determination result as an embodiment of the present invention.

FIG. 4 is a block diagram showing a configuration in which channel selection is linked to a surrounding environment determination result as an embodiment of the present invention.

FIG. 5 is a flowchart illustrating a determination method of a surrounding environment determination unit in the embodiment of FIGS. 2 to 4;

FIG. 6 is a flowchart illustrating an example of a processing flow in a display selector as an embodiment of the present invention.

FIG. 7 is a flowchart illustrating an example of a processing flow of a radio wave intensity determination unit as an embodiment of the present invention.

FIG. 8 is a flowchart showing an example of a processing flow of a narrow area / wide area command generation unit as an embodiment of the present invention.

FIG. 9 is a flowchart illustrating an example of a processing flow of a channel selection unit as an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 ... Antenna 12 ... Front end 13 ... Propagation analysis part 131 ... Roll-off filter 132 ... Signal delay circuit 133 ... AGC processing circuit 134 ... Matched filter 14 ... Pilot channel reception processing part 141 ... Despreading circuit 142 ... Rake combining circuit 143 ... Viterbi decoding circuit 144 Byte deinterleaving circuit 145 RS decoding circuit 15 First broadcast channel reception processing unit 151 Despreading circuit 152 Rake combining circuit 153 Bit deinterleaving circuit 154 Viterbi decoding circuit 155 Byte deinterleaving circuit 156 RS decoding circuit 16 second broadcast channel reception processing section 161 despreading circuit 162 rake combining circuit 163 bit deinterleaving circuit 164 Viterbi decoding circuit 165 byte deinterleaving circuit 166 R Decoding circuit 17: Third broadcast channel reception processing unit 171: Despreading circuit 172 ... Rake combining circuit 173 ... Bit deinterleaving circuit 174 ... Viterbi decoding circuit 175 ... Byte deinterleaving circuit 176 ... RS decoding circuit 18 ... Path search unit 19 ... Demodulation control unit 20 Multiplexing unit 21 Reproduction processing unit 211 Distribution circuit (DEMUX) 212 MPEG-4 decoder 213 AAC decoder 214 Data broadcast decoder 31 Ambient environment determination unit 32 Equalizer screen display selector 33 Equalizer Display pattern registration memory 34 ... Graphic equalizer 35 ... Background screen display selector 36 ... Background display pattern registration memory 37 ... Display device 38 ... Radio field intensity determination unit 39 ... Reception sensitivity display processing unit 40 ... Level meter 41 ... Numerical display 42 … Narrow area・ Wide area command generator 43 ... Display of car navigation system 44 ... Channel selector 45 ... Digital broadcast receiver

Claims (8)

[Claims] 1. A mobile receiving terminal device for receiving a transmission signal according to a CDM (Code Division Multiplexing) modulation method, comprising: a radio wave state identification unit for identifying a change in a radio wave state by a path search of the reception signal; Reproducing means for reproducing the demodulated output; and reproducing system control means for changing a reproduced output of the reproducing means or an additional reproduced output linked to the reproduced output in accordance with a result of the identification by the radio wave state identifying means. A mobile receiving terminal device characterized by the above-mentioned. 2. The radio wave state identifying unit according to claim 1, wherein the radio wave state identifying unit identifies a change in a radio wave state from at least one of the number of paths, received power intensity, and delay amount obtained by the path search. Mobile receiving terminal. 3. The mobile reception terminal device according to claim 2, further comprising reception sensitivity display means for displaying reception power intensity of a path obtained by said radio wave state identification means as reception sensitivity information. 4. The mobile reception terminal device according to claim 3, wherein said reception sensitivity display means displays the total sum of reception power including multipaths by adding or subtracting the sum of the number of paths. 5. The reproduction means includes a spectrum analyzer for analyzing and displaying a frequency spectrum of the reproduction output, and the reproduction system control means controls a display color of the spectrum analyzer according to an identification result of the radio wave state identification means. The mobile reception terminal device according to claim 1, wherein the display format is changed. 6. The reproduction means includes an image display means, and the reproduction system control means changes a background image displayed on the image display means in accordance with an identification result of the radio wave state identification means. The mobile receiving terminal device according to claim 1. 7. When the map is displayed on the image display means, the reproduction system control means changes the scale of the map displayed on the image display means according to the identification result of the radio wave state identification means. The mobile receiving terminal device according to claim 6, wherein: 8. The transmission signal comprises a plurality of channels,
When different information is transmitted in each channel, the reproducing unit includes a channel selecting unit, and the reproducing system controlling unit causes the channel selecting unit to select a channel according to the identification result of the radio wave state identifying unit. The mobile receiving terminal device according to claim 1, wherein: