JP2002305452A - Information receiver, information transmitter and information receiving system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an information receiver, an information transmitter and an information receiving system, in which the circuit scale can be reduced by controlling the time to be elapsed, until information is reproduced. SOLUTION: The information receiver comprises a Bluetooth receiving section 13 for receiving and demodulating information transmitted from the transmitting side 1, a Bluetooth link controller and a CPU 14, an input buffer 14 for storing demodulated compressed information temporarily, and a DSP, for controlling writing or reading of compressed information to or from the input buffer 14, depending on the compression rate of compressed information wherein the depth of storage capacity of the input buffer 14 can be controlled, depending on the compression rate and the capacity can be saved by the amount corresponding to the compression rate, because compressed information is stored in the input buffer 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information receiving apparatus, an information transmitting apparatus, and an information receiving system for receiving information transmitted from a transmitting side and reproducing the received information.

[0002]

2. Description of the Related Art Conventionally, an information receiving apparatus that transmits information from a transmitting side to a receiving side, and receives and reproduces the information at the receiving side, has performed transmission of the Bluetooth standard.
In the transmission of the Bluetooth standard, information is retransmitted by changing the transmission rate. When retransmitting this information, the information is not interrupted even if the number of retransmissions is increased as the buffer capacity is made relatively large in consideration of a sudden change in the transmission rate.

[0003]

However, in the conventional information receiving apparatus described above, the time of the latent state of the information in the information receiving apparatus is reduced by relatively increasing the capacity of the buffer for retransmitting the information. Latency (L
Attention) becomes longer, so that it takes a longer time before information is reproduced.

[0004] For this reason, in the information receiving apparatus, for example, when it is necessary to synchronize the audio data and the video data, there is a disadvantage that it is difficult to synchronize.

[0005] Further, in the information receiving apparatus, when the sound quality is emphasized, or in an application under a bad electric field environment, the buffer capacity is set to be relatively large, and when the latency is shortened so as to satisfy the specification, It is required to use the buffer properly so that the buffer capacity is set relatively small, but there is an inconvenience that there is no information receiving apparatus for controlling the buffer capacity.

Further, in the information receiving apparatus, since the amount of information to be written to or read from the buffer is large, there is a disadvantage that the circuit scale is increased.

Therefore, the present invention has been made in view of the above points, and an information receiving apparatus, an information transmitting apparatus, and an information receiving apparatus capable of controlling a time until information is reproduced and reducing a circuit scale. It is an object to provide a system.

[0008]

According to the present invention, there is provided an information receiving apparatus comprising: a transmitting side which samples information at a predetermined transmission sampling frequency, compresses the information, and transmits the information at a transmission frequency asynchronous with the transmission sampling frequency; An information receiving apparatus that expands compressed information demodulated in synchronization with a transmission rate based on the transmission frequency on the reception side, samples the data at a predetermined reception sampling frequency, and reproduces the information, receives and demodulates information transmitted from the transmission side. Receiving means;
Storage means for temporarily storing the demodulated compression information,
Control means for controlling writing of the compression information to the storage means or reading of the compression information in accordance with the compression ratio of the compression information.

Further, the information transmitting apparatus of the present invention expands the demodulated compressed information in synchronization with the transmission rate on the receiving side, and samples and reproduces the compressed information at a predetermined receiving sampling frequency. In an information transmitting apparatus for transmitting information at a transmission frequency that is asynchronous with the transmission sampling frequency after being compressed after being sampled at a sampling frequency, a compression ratio setting unit that sets a compression ratio of information to be transmitted; Transmission means for transmitting the compressed information with a compression ratio added thereto.

[0010] The information receiving system of the present invention may be configured to receive information compressed at a predetermined transmission sampling frequency from an information transmitting apparatus and then transmitted at a transmission frequency asynchronous with the transmission sampling frequency. In an information receiving system that expands compressed information demodulated in synchronization with a transmission rate on a device side and samples and reproduces the compressed information at a predetermined reception sampling frequency, the information transmitting device includes a compression unit that sets a compression ratio of information to be transmitted. Rate setting means, and transmission means for adding a compression rate to the information compressed at the compression rate and transmitting the information, the information receiving apparatus receives information transmitted from a transmission side and demodulates the reception means; Storage means for temporarily storing the demodulated compression information, and writing of the compression information to the storage means or reading of the compression information The in which and a control means for controlling the compression ratio of the compression information.

Therefore, according to the present invention, the following operations are performed. The information receiving device operates as follows. The compressed information that is compressed after being sampled from the transmission side at a predetermined transmission sampling frequency and transmitted at a transmission frequency that is asynchronous to the transmission sampling frequency is demodulated on the reception side in synchronization with the transmission rate according to the transmission frequency. In an information receiving apparatus for sampling and reproducing at a predetermined reception sampling frequency, the receiving means receives and demodulates information transmitted from the transmitting side, and the storage means temporarily stores the demodulated compressed information and performs control. The means controls writing of the compressed information to the storage means or reading of the compressed information according to the compression ratio of the compressed information.

[0012] The information transmitting apparatus of the present invention operates as follows. In order to expand the compressed information demodulated in synchronization with the transmission rate on the receiving side and to sample and reproduce at the predetermined receiving sampling frequency, the data is sampled at the predetermined transmitting sampling frequency from the transmitting side and then compressed and transmitted. In an information transmitting apparatus that transmits information at an asynchronous transmission frequency, the compression ratio setting unit sets the compression ratio of the information to be transmitted, and the transmission unit adds the compression ratio to the information compressed at the compression ratio and transmits the information. I do.

The information receiving system of the present invention operates as follows. Information compressed at a transmission frequency that is asynchronous with the transmission sampling frequency after being sampled at a predetermined transmission sampling frequency from the information transmission device side, and compressed information demodulated in synchronization with the transmission rate at the information reception device side. In an information receiving system that expands and samples and reproduces at a predetermined receiving sampling frequency,
The information transmitting device sets the compression ratio of the information transmitted by the compression ratio setting unit, adds the compression ratio to the information compressed at the compression ratio by the transmitting unit, and transmits the information. The information receiving device transmits the information by the receiving unit. Receiving and demodulating the information transmitted from the side, temporarily storing the compressed information demodulated by the storage means, and writing the compressed information to the storage means or reading the compressed information to the storage means by the control means to the compression rate of the compressed information. Control according to.

[0014]

Embodiments of the present invention will be described below. The information receiving device of the present embodiment is a Bluetooth device.
When playing hi-fi audio with the other audio profile, the DSP (Digital Signal)
l Processor just before the buffer RAM (R
By buffering the compressed data by arranging an random access memory, the asynchronousity can be absorbed with a small RAM capacity, and the capacity of the buffer RAM can be changed and controlled by an application.

FIG. 1 is a block diagram showing the configuration of the information transmission system according to the present embodiment. The information transmission system according to the present embodiment includes an information transmitting device on the transmitting side 1 and an information receiving device on the receiving side 2.

The information transmitting device of the transmitting side 1 is an ADC that converts transmission information from an information supply source (not shown) into digital data.
(Analog Digital Converte
r) A clock generator 4 for generating 2 and 512 fs, a clock generating circuit 5 for generating a clock CLK1, and an interface for digitally converted data by the ADC 2 using the clock CLK1, using the transmission side synchronization signal S1 (E
XEC) and an ADC I / F3
An input buffer 6 for temporarily storing the data subjected to the interface processing in F3, and a DSP 7 for compressing the data temporarily stored in the input buffer 6 using the transmission-side synchronization signal S1 (EXEC). Be composed.

The information transmitting device of the transmitting side 1 is a DSP.
7, an output buffer 8 for temporarily storing the data subjected to the compression processing, and a Bluetooth for compressing the data temporarily stored in the output buffer 8 according to the Bluetooth standard.
th link controller and CPU (Central
Processor Unit 9) and Bluetooth
a control register 10 for supplying a compression ratio setting signal S3 and a bank switching signal S4 as various setting signals to the DSP 7 and the output buffer 8 according to a control signal S2 from the other link controller and the CPU 9;
Bluetooth that transmits information according to the Bluetooth standard
and a tooth transmission unit 11.

The information receiving device on the receiving side 2 is a Blu-ray receiving device.
Bluetooth that receives information according to the Bluetooth standard
and the data temporarily stored in the input buffer 15 and the memory read interrupt signal S1 (ARM
Read int) and launched by Bluetooth
h, the Bluetooth link controller and the CPU 14 for decompressing the data, the input buffer 15 for temporarily storing the data decompressed by the Bluetooth link controller and the CPU 14, and the data temporarily stored in the input buffer 15 for receiving-side synchronization. Signal S17
Rate monitor 1 that monitors the rate at the time of reading using (EXEC) and generates monitor rate S16
5 'and a memory read interrupt signal S1 (ARM R
and a DSP 17 for generating frame information (head int) and frame interpolation information S5 and for expanding data temporarily stored in the input buffer 15 by using a reception-side synchronization signal S17 (EXEC). Bluetooth
The link controller and the CPU 14 have f1 (32
kHz), and the Bluetooth link controller and the CPU 14 and the DSP 17 are provided with f2
(26 MHz).

The information receiving device on the receiving side 2 is a Blu-ray receiver.
A control register 16 that supplies a bank switching signal S13 and an expansion rate setting signal S14 as various setting signals to an input buffer 15 and a DSP 17 according to a control signal S12 from the Ethernet link controller and the CPU 14, and a frame that has undergone expansion processing by the DSP 17 Output buffer 1 for temporarily storing a frame interpolation process based on a decompression process using interpolation information S5
8, 512 fs clock oscillator 20, 512 fs
And a clock generation circuit 21 for generating a clock CLK2 based on the monitor rate S16 and an interface for the data temporarily stored in the output buffer 18 using the clock CLK2 to receive the synchronization signal S17 (EX
And a DAC (Digital) 19 for converting digital data into analog information.
(Analog Converter) 22.

Note that the above-mentioned sampling frequency fs
Considering that the frequency is 44.1 KHz or 48 KHz, a clock oscillator of 1024 fs may be provided for the sampling frequency fs.

Further, the sampling frequency fs in the information transmitting device on the transmitting side 1 and the sampling frequency fs in the information receiving device on the receiving side 2 are also asynchronous. Eventually, unless the sampling frequency fs is synchronized with the information transmitting device on the transmitting side 1 and the information receiving device on the receiving side 2, audio data is not continuously reproduced as sound.

Therefore, in the information receiving apparatus of the receiving side 2, the rate at which data is read out from the input buffer 15 at the sampling frequency fs of the receiving side is monitored by the rate monitor 15 ', and the clock CLK of the receiving side is monitored.
2 is synchronized by feeding back to the clock generation circuit 21 for generating the signal 2.

The operation of the thus configured information transmission system according to the present embodiment will be described below.

First, the operation of the information transmitting apparatus on the transmitting side 1 will be described. The ADC 2 converts transmission information from an information source (not shown) into digital data. The clock generation circuit 5
Using 512 fs from clock oscillator 4, clock C
Generate LK1. The ADC I / F 3 interfaces the digitally converted data by the ADC 2 using the clock CLK 1 to transmit the synchronization signal S 1 (EX).
EC). The input buffer 6 has an ADC I / F
In step 3, the data subjected to the interface processing is temporarily stored. The control register 10 has a Bluetooth
A compression ratio setting signal S3 and a bank switching signal S4 are supplied to the DSP 7 and the output buffer 8 as various setting signals in response to a control signal S2 from the th link controller and the CPU 9. The DSP 7 performs compression processing on the data temporarily stored in the input buffer 6 by using the transmission-side synchronization signal S1 (EXEC) based on the compression ratio setting signal S3.

The output buffer 8 temporarily stores the data subjected to the compression processing in the DSP 7 in each bank based on the bank switching signal S4. The Bluetooth link controller and the CPU 9 compress the data temporarily stored in the output buffer 8 according to the Bluetooth standard. The Bluetooth transmission unit 11 transmits the Bluetooth
The information is transmitted according to the other standard.

Next, the operation of the information receiving apparatus on the receiving side 12 will be described. The Bluetooth receiving unit 13
Information is received according to the tooth standard. Bluetooth
The other link controller and the CPU 14 store the data temporarily stored in the input buffer 15 in response to the memory read interrupt signal S1 (ARMRead int).
Decompression processing is performed according to the Bluetooth standard. Input buffer 15
Is a Bluetooth link controller and CP
The data subjected to the expansion processing in U14 is transmitted to the bank switching signal S
13 and temporarily stored in each bank. The rate monitor 15 'monitors the rate at which data temporarily stored in the input buffer 15 is read out using the reception-side synchronization signal S17 (EXEC), and generates a monitor rate S16. The DSP 17 outputs the memory read interrupt signal S
1 (ARM Read int) and frame interpolation information S5 are generated, and the data temporarily stored in the input buffer 15 is subjected to decompression processing using the reception-side synchronization signal S17 (EXEC) based on the decompression ratio setting signal S14.

The control register 16 stores Bl
A bank switching signal S13 and an expansion rate setting signal S14 are supplied to the input buffer 15 and the DSP 17 as various setting signals in accordance with a control signal S12 from the Bluetooth link controller and the CPU 14. The output buffer 18 performs a frame interpolation process based on the extension process on the data subjected to the extension process by the DSP 17 using the frame interpolation information S5, and temporarily stores the data. The clock generation circuit 21 generates a clock CLK2 based on 512 fs from the clock oscillator 20 and the monitor rate S16. The DACI / F 19 controls the interface of the data temporarily stored in the output buffer 18 with the clock CL.
The reception side synchronization signal S17 (EXEC) is performed using K2.
Generate The DAC 22 converts digital data into analog information.

In the information transmitting apparatus of the transmitting side 1 described above, the audio data of two channels sampled at 44.1 KHz of the sampling frequency fs is converted into D data.
Compressed to about 300 kbps by SP7, Blue
tooth link controller and CPU 14 and Bl
Bluetooth A by the Bluetooth transmission unit 11
The data is added to the payload of the L2CAP according to the transmission protocol of the UDIO standard, modulated, and transmitted.

Then, in the information receiving apparatus of the receiving side 2, the Bluetooth receiving unit 13 and the Bluetooth
After demodulation by the h-link controller and the CPU 14, the transmission protocol of the Bluetooth AUDIO standard is analyzed. The receiving side sampling frequency fs is
Compressed data is read from the input buffer 15 for each reception-side synchronization signal S17 (EXEC) having a fixed period measured using the clock CLK2 according to the above, converted into linear audio data, and 44.1K of the sampling frequency fs.
Reproduction is performed with a sampling clock in Hz.

The input buffer 15 in the information receiving device of the receiving side 2 described above is provided with a control signal S12 from the Bluetooth link controller and the CPU 14.
By controlling the write address and the read address by the bank switching signal S13 from the control register 16 according to the above, the address space usable for the input buffer 15 can be freely set. It is possible to control the depth of capacity, and it is possible to control the time from transmission to reception until sound is output.

FIG. 2 is a diagram showing the operation of the transmission system. FIG. 2 shows the input buffer 1 of the information receiving apparatus on the receiving side 12 of the information transmission system according to the present embodiment shown in FIG.
5 is a diagram illustrating an operation of FIG.

First, in the information transmitting apparatus of the transmitting side 1,
The transmission information from the disc player 23 as an information supply source is converted into digital as described above, compressed, and supplied to the Bluetooth transmission unit 11 by bank switching. The Bluetooth transmission unit 11
Information is transmitted according to the tooth standard.

Next, in the information receiving apparatus on the receiving side 12, the Bluetooth receiving unit 13
Information is received according to the th standard. Bluetooth
The link controller and the CPU 14 expands data temporarily stored in the input buffer 15 according to the Bluetooth standard. The input buffer 15 is a Bluetooth
The data subjected to the expansion processing by the th link controller and the CPU 14 is temporarily stored in each bank based on the address control 28.

The DSP 17 expands the data temporarily stored in the input buffer 15. The amplifier 24 amplifies the expanded data. The speaker 25 outputs the amplified data as sound.

Here, the data stored in the input buffer 15 is compressed data 27 compressed by the DSP 7 of the information transmitting apparatus on the transmitting side 1 at a variable compression ratio 26. That is, the input buffer 15 temporarily stores the compressed data 27 in each bank under the address control 28 based on the variable compression ratio 26 of the compressed data 27.

FIG. 3 is a diagram showing the setting of the compression ratio for the control register of the transmitting CPU. FIG. 3 shows settings made by the Bluetooth link controller and the CPU 9 of the information transmission device of the transmission side 1 to the control register 10.

In FIG. 3, the sampling frequency fs3
As 1, 2-bit data is used as shown by 32 and 48 KHz or 44.1 KHz as shown by 33
Is used. As the bit rate 34 indicating the compression rate, 3-bit data is used as indicated by 35,
As shown by 36, seven patterns of 80 to 300 kbps are used. As the channel 37, 2-bit data is used as shown by 38, and monaural or stereo is used as shown by 39.

Here, the compression rate setting signal S3 and the bank switching signal S4 are generated at the bit rate 34 set by the control signal S2. The compression ratio setting signal S3 is supplied to the DSP 7. The bank switching signal S4 is supplied to the output buffer 8. Although not shown, a sampling frequency switching signal is generated by the sampling frequency fs31. The sampling frequency switching signal is
The clock is supplied to the clock generation circuit 5. Also, channel 3
7, a channel switching signal is generated. The channel switching signal is supplied to a stage preceding the ADC 2.

FIG. 4 is a diagram showing a data format on the transmission path. In FIG. 4, a Bluetooth header 41 according to the Bluetooth standard and an ATRAC
(Adaptive Transform Acous
ticCoding) 3 format compressed data 42
Are the data on the transmission path. The ATRAC3 format compressed data 42 includes a header 43 and ATRAC data 44. The header 43 has a compression ratio of 4
5 is described. In the header 43, the sampling frequency fs31, the bit rate 34 indicating the compression ratio 45, and the channel 37 shown in FIG. 3 are described.

In the information receiving apparatus on the receiving side 12, Bl
Bluetooth link controller and CPU 14
ATRAC using an expansion rate signal based on a compression rate 45
The data 44 is expanded.

FIG. 5 is a diagram showing buffer control on the receiving side. FIG. 5 shows the buffer control for the input buffer 15 of the information receiving device on the receiving side 12. In FIG. 5, for example, bank 1 (51), bank 2 (52), and bank 3 (5
3) is used for the write address control 57, and the banks 4 (54) and 5 (55) of the input buffer 15 are used.
And the bank 6 (56) is used for the read address control 58.

FIG. 6 is a diagram showing the address control of the receiving buffer. FIG. 6A shows the write data according to the compression ratio, and FIG. 6B shows the write address and the read address according to the compression ratio. In FIG. 6, three banks, bank 1 (61), bank 2 (62) and bank 3 (63), of the input buffer 15 are used for write address control, and banks 4 (64), bank 5 of the input buffer 15 are used.
(65) and bank 6 (66) are used for read address control.

In FIG. 6A, when the compression ratio is 1/2, the write data is divided into a leading portion 61-1 of the bank 1 (61) of the input buffer 15 and a leading portion 62- of the bank 2 (62).
1 and the leading portion 63-1 of the bank 3 (63).

In FIG. 6A, when the compression ratio is 1/4, the write data of the input buffer 15 includes a head portion 61-1-1 of the bank 1 (51), a head portion 61-1-1, and a bank 2 (52). Further head part 62 of head part 62-1
-1-1 and the leading portion 63-1-1 of the leading portion 63-1 of the bank 3 (53).

In FIG. 6B, the write address W when the compression ratio is 1/2 is stored in the bank 1 (6
In the first part 61-1 of 1), the read address R is set to 4
By setting the leading portion 64-1 of the bank 4 (63) of the frame, the latency (Latenc) indicating the time of the latent state of the information in the information receiving apparatus of the receiving side 1 is set.
y) can be varied.

In FIG. 6B, the write address W at the compression ratio of 1/4 is stored in the bank 1 (5
Further, the leading portion 61-1-1 of the leading portion 61-1 of 1)
, The read address R is stored in the bank 4 of the fourth frame.
Further leading part 64-1 of leading part 64-1 of (63)
By setting the head portion 68-1-1 of the eighth frame from −1, the latency (Latenc) indicating the time of the latent state of the information in the information receiving apparatus of the receiving side 1 is obtained.
y) can be varied.

FIG. 7 is a diagram showing the control of the write address and the read address based on the compression ratio. FIG. 7 shows the control of the write address and the read address of the input buffer 15 of the information receiving device on the receiving side 12 by the control based on the compression ratio. Buffer memory 71
Corresponds to the input buffer 15.

In FIG. 7, a Bluetooth link controller and a CPU of the information receiving apparatus on the receiving side 12 are shown.
14 generates a control signal 76 based on the compression ratio. The control signal 76 causes the buffer memory 7
Write address 72 and read address 73 for 1 are controlled.

At this time, the read address 73 = write address 72 + address distance / compression ratio is set as an initial value. As a result, the write data 74 is written to the write address 72, and the read data 75 is read from the read address 73.

FIG. 8 is a diagram showing a control example. FIG.
It shows the control of the write address and the read address according to the compression ratio for the input buffer 15 of the information receiving device on the receiving side 12.

In FIG. 8, the compression ratio 1
/ 2, at time t = 0, E in the storage area 81 of the memory
0 sets the write address W to E8 for the data 82-0 of the read address R, and at time t = 1, E4 of the storage area 81 of the memory sets the write address W to E14 for the data 82-1 of the read address R. At time t = 2, E8 of the storage area 81 of the memory sets the write address W to E22 for the data 82-2 of the read address R,.
At time t = n, En of the storage area 81 of the memory becomes the write address W with respect to the data 82-n of the read address R.
And E6, the position of the write address W with respect to the read address R is sequentially increased even at the same compression ratio, so that the latency (Latency) indicating the time of the latent state of the information in the information receiving apparatus of the receiving side 1 is continuously set. Can be changed.

As shown by 83, when the compression ratio is 1/4, t
= 0, E0 of the storage area 81 of the memory sets the write address W to the data 83-0 of the read address R to
4, at time t = 1, E2 of the memory storage area 81 sets the write address W to E7 for the data 83-1 of the read address R, and at time t = 2, the memory storage area 8
The E4 of No. 1 sets the write address W to E9... For the data 83-2 of the read address R, and even at the same compression ratio, the position of the write address W with respect to the read address R is sequentially increased so that The latency indicating the time of the latent state of information in one information receiving device can be continuously changed.

In the above-described embodiment, the transmitting side 1
The Bluetooth transmitting unit 11 of the information transmitting apparatus includes an encoding unit that generates packet data for transmission according to the Bluetooth standard based on a compression ratio of the compressed data, and a Bluetooth that transmits the compressed data that has been subjected to the compression processing.
Bluetooth that performs high-frequency signal processing according to the oot standard
oth signal processing unit.

Also, the information receiving device on the receiving side 12
The Bluetooth reception unit 13 includes a Bluetooth signal processing unit that performs high-frequency signal processing according to the Bluetooth standard on compressed data that has been subjected to compression processing, and a decoding unit that analyzes packet data.

The transmitting side 1 operates as follows. The DSP 7 uses the compression ratio for the data in Blue.
A compression process for transmission according to the tooth standard is performed to generate compressed data that has been compressed. The encoding unit
A header is added to the compressed data, a compression ratio is described in the header, and packet data is generated. Bluetooth
The Bluetooth signal processing unit of the transmission unit 11 performs high-frequency signal processing based on the Bluetooth standard on the compressed data that has been subjected to the compression processing.

The DSP 7 uses, for example, a compression method based on ATRAC3. The compression rate of the compression method according to the ATRAC3 standard is, for example, 128 kbps / channel.
It is about l.

The receiving side 12 operates as follows. Bluetooth of the Bluetooth receiving unit 13
h signal processing unit performs B processing on the compressed data
Performs high-frequency signal processing according to the Bluetooth standard. The decoding unit analyzes the packet data and extracts a compression ratio from the header. The DSP 17 performs expansion processing for reception according to the Bluetooth standard on the data at an expansion rate based on the compression rate, and generates expanded data.

Although not shown, Bluetooth
The transmitting and receiving unit includes an antenna for receiving and transmitting a wireless transmission signal according to the Bluetooth standard, and an FSK (Frequency) according to the Bluetooth standard for receiving and transmitting.
RF (Radio Fr) for radio-frequency signal processing of radio transmission signals by ncy Shift Keying
equipment), a baseband unit for performing baseband signal processing for establishing and controlling links, a CPU for analyzing and controlling data transfer protocols such as data formatting such as data division and assembly, flow control, and control data. S (Stati
c) It comprises a RAM, a flash memory for storing various parameters according to specifications, and a host interface for interfacing with a host controller. In addition, 13KHz, 16MHz, 1M
And a crystal oscillator that generates a reference clock for enabling generation of a Bluetooth clock essential for a Bluetooth transmission / reception unit at a frequency of 1600 KHz or the like.

The Bluetooth transmission unit 11 and the Bluetooth reception unit 13 shown in FIGS.
The ooth signal processing unit corresponds to the RF unit, and the encoding unit and the decoding unit correspond to the baseband unit and the CPU.

Blu as a short-range wireless data communication system
In the Bluetooth standard, for example, a CVSD (Continuous V) is used using a frequency band of 2.4 GHz.
Some data can be used at a data transfer rate of 64 kbps, depending on the audio coding method (ariable Slope Delta).
By performing signal processing using a coding scheme for Haifa such as ATRAC3 at a sampling frequency fs of 48 KHz, for example, it is possible to transmit a CD (Compact Disc) level fifi-fi sound quality.
adopts the tooth AUDIO standard.

In the above-described embodiment, an example has been described in which transmission between the information transmitting apparatus on the transmitting side 1 and the information receiving apparatus on the receiving side 12 is performed by short-distance wireless transmission according to the Bluetooth standard. Not limited to wireless IEEE
The present invention may be applied to a case where wireless transmission of the 1394 standard and the IEEE 802.11b standard is performed.

[0062]

According to the information receiving apparatus of the present invention, information transmitted from a transmitting side at a predetermined transmitting sampling frequency and then compressed and transmitted at a transmitting frequency asynchronous with the transmitting sampling frequency is transmitted to the receiving side at a transmitting frequency. A receiving means for receiving and demodulating information transmitted from a transmitting side in an information receiving apparatus for expanding compressed information demodulated in synchronization with a transmission rate according to the above, and sampling and reproducing the compressed information at a predetermined reception sampling frequency. A storage unit for temporarily storing the compressed information; and a control unit for controlling writing of the compressed information to the storage unit or reading of the compressed information in accordance with the compression ratio of the compressed information. The depth can be controlled according to the compression ratio, and the compressed data is stored in the storage means, so that the capacity is saved by the compression ratio. An effect that it is possible to provide an information receiving apparatus capable.

In the information receiving apparatus according to the present invention, the control means controls the write address of the compressed information in the storage means, so that the address space usable for the storage means can be freely set. Accordingly, it is possible to control the depth of the capacity of the storage means, and it is possible to control the time from reception to when a sound is output.

In the information receiving apparatus according to the present invention, in the above, the control means controls the read address of the compressed information from the storage means, so that the address space usable for the storage means can be freely set. Accordingly, it is possible to control the depth of the capacity of the storage means, and it is possible to control the time from reception to when a sound is output.

Further, in the information receiving apparatus of the present invention, the control means controls the capacity of the storage means according to the application, so that the application indicates the time of the latent state of information in various information receiving apparatuses. Latency (Latency) can be set. For example, the depth of the storage capacity of the storage means is reduced for applications such as a microphone that requires synchronization than sound quality, and the emphasis is on sound quality rather than synchronization such as wireless headphones. For an application, there is an effect that the range of application can be expanded by increasing the storage capacity of the storage means.

In the information receiving apparatus according to the present invention, the receiving means analyzes the packet data of the information transmitted from the transmitting side and extracts the compression ratio from the header. This has the effect that the rate can be extracted on the receiving side and used for control when storing the compressed information.

The information transmitting apparatus of the present invention expands the demodulated compressed information in synchronization with the transmission rate on the receiving side, samples the compressed information at a predetermined receiving sampling frequency, and reproduces the compressed information. In an information transmitting apparatus that transmits information at a transmission frequency that is asynchronous with the transmission sampling frequency after being compressed after being sampled at a sampling frequency, a compression ratio setting unit that sets a compression ratio of information to be transmitted; Transmission means for adding a compression rate to the information which has been transmitted, so that the information to be transmitted can be transmitted with the compression rate added thereto. There is an effect that it is possible to provide an information transmitting device capable of saving the capacity of the information transmitting device.

Further, the information receiving system of the present invention converts the information which has been sampled from the information transmitting apparatus at a predetermined transmitting sampling frequency and then compressed and transmitted at a transmitting frequency asynchronous with the transmitting sampling frequency to the information receiving apparatus. In an information receiving system that expands compressed information demodulated in synchronization with a transmission rate on the side and samples and reproduces the compressed information at a predetermined reception sampling frequency, an information transmission apparatus sets a compression rate for setting a compression rate of information to be transmitted. Means for transmitting the information compressed at the compression rate with a compression rate added thereto, the information receiving apparatus comprising: a receiving means for receiving and demodulating information transmitted from the transmitting side; A storage unit for temporarily storing information, and writing or reading of the compressed information to or from the storage unit is controlled according to the compression ratio of the compressed information. The information transmitting apparatus can transmit the information to be transmitted with a compression rate added thereto, and can transmit the compressed data, thereby saving the capacity of the transmission means by the compression rate. The information receiving device can control the depth of the storage capacity of the storage means in accordance with the compression ratio, and since the compressed data is stored in the storage means, the information receiving apparatus can save the capacity by the compression rate. There is an effect that a system can be provided.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a transmission system according to the present embodiment.

FIG. 2 is a diagram illustrating an operation of the transmission system.

FIG. 3 is a diagram showing a compression ratio setting for a control register of a transmitting CPU.

FIG. 4 is a diagram showing a data format on a transmission path.

FIG. 5 is a diagram illustrating reception-side buffer control.

6A is a diagram showing address control of a receiving buffer, and FIG. 6A shows write data according to a compression ratio;
B is a diagram showing a write address and a read address according to the compression ratio.

FIG. 7 is a diagram showing control of a write address and a read address based on a compression ratio.

FIG. 8 is a diagram illustrating a control example.

[Explanation of symbols]

1 ... Sending side, 2 ... ADC, 3 ... ADC I / F,
4 ... 512 fs, 5 ... clock generation unit, 6 ... input buffer, 7 ... DSP, 8 ... output buffer, 9 ...
Bluetooth link controller and CPU,
10: Control register, 11: Bluetooth
o th transmission unit, 12 ... receiving side, 13 ... Bluetooth
oth receiving unit, 14 ... Bluetooth link controller and CPU, 15 ... input buffer, 15 '
... Rate monitor, 16 ... Control register, 1
7 ... DSP, 18 ... Output buffer, 19 ... ADC
I / F, 20 ... 512 fs, 21 ... Clock generation unit, 22 ... DAC, 23 ... Disc player, 24
... Amplifier, 25 ... Speaker, 26 ... Variable compression ratio,
27 ... compressed data, 28 ... address control,
31 ... sampling frequency fs, 32 ... 2 bits,
33 ... 48KHz / 44.1KHz, 34 ... Bit rate, 35 ... 3 bits, 36 ... 7 patterns, 37
... channel, 38 ... 2 bits, 39 ... monaural / stereo, 41 ... Bluetooth header, 42
... ATRAC3 format compressed data, 43 ... header, 44 ... ATRAC data, 45 ... compressed data, 51 to 56 ... bank 1 to bank 6, 57 ... write address control, 58 ... read address control, 61 -1 to 63-1 ... head of bank (compression ratio 1/2), 61-1-1 to 63-1-1 ... head of bank (compression ratio 1/4), 71 ... buffer memory,
72 write address, 73 read address, 7
4 Write data, 75 Read data, 76
Control, 81 ... memory storage area, 82-0
82-n... Data with a compression ratio of 1/2, 83-0 to 83-
2. Data with a compression ratio of 1/4

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Claims (7)

[Claims] 1. A receiving side synchronizes information that has been sampled at a predetermined transmission sampling frequency and then compressed and transmitted at a transmission frequency that is asynchronous with the transmission sampling frequency to a transmission rate based on the transmission frequency at a reception side. An information receiving apparatus for expanding and demodulating compressed information demodulated by sampling at a predetermined reception sampling frequency and reproducing the information; a receiving means for receiving and demodulating information transmitted from a transmitting side; An information receiving apparatus comprising: a storage unit that stores the compressed information in the storage unit; and a control unit that controls writing of the compressed information to the storage unit or reading of the compressed information in accordance with a compression ratio of the compressed information. . 2. An information receiving apparatus according to claim 1, wherein said control means controls a write address of said compressed information in said storage means. 3. The information receiving apparatus according to claim 1, wherein said control means controls a read address of said compressed information from said storage means. 4. The information receiving apparatus according to claim 1, wherein said control means controls a capacity of said storage means according to an application. 5. An information receiving apparatus according to claim 1, wherein said receiving means analyzes packet data of information transmitted from said transmitting side and extracts a compression ratio from a header. . 6. In order to expand compressed information demodulated in synchronization with a transmission rate on a receiving side and to sample and reproduce the compressed information at a predetermined receiving sampling frequency, the compressed information is compressed after being sampled at a predetermined transmitting sampling frequency from the transmitting side. An information transmitting apparatus that transmits information at a transmission frequency that is asynchronous with the transmission sampling frequency; a compression ratio setting unit that sets a compression ratio of information to be transmitted; and a compression ratio for the information compressed at the compression ratio. An information transmitting apparatus, comprising: transmitting means for additionally transmitting. 7. The information transmitting apparatus synchronizes information compressed at a predetermined transmission sampling frequency and transmitted at a transmission frequency asynchronous with the transmission sampling frequency with the transmission rate at the information receiving apparatus. In an information receiving system for expanding and demodulating compressed information demodulated by sampling at a predetermined reception sampling frequency and reproducing the information, the information transmitting apparatus includes: a compression rate setting unit configured to set a compression rate of information to be transmitted; Transmitting means for adding a compression rate to the information compressed in step (b), and transmitting the information. The information receiving apparatus receives the information transmitted from the transmitting side and demodulates the information. Storage means for temporarily storing, and writing of the compressed information to the storage means or reading of the compressed information to the compression rate of the compressed information Information reception system comprising: the control means, the controlling by Flip.