JP2005026912A - Radio apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a radio apparatus which reduces the quantity of a volatile memory and the power consumption. <P>SOLUTION: The radio apparatus 100 uses MRAMs which have high read and write speed and do not lose the memory contents with power off for nonvolatile memories A114 and B115. This eliminates the need to copy programs in a rewritable memory from a non-rewritable memory, every time the apparatus is powered on. Thus, in designing a modem LSI 110 for a radio terminal 100, the quantity of a volatile memory can be greatly reduced, compared with the conventional modem LSI. Since the volatile memory consumes power largely, the power consumption is reduced. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a wireless device that performs wireless communication, and more particularly to a wireless device that performs wireless communication by digital signal processing.
[Prior art]
Conventionally, there is a wireless device that includes both hardware processing and processor processing (see, for example, Patent Document 1).
In this radio apparatus, the radio signal received from the antenna is frequency-converted by the radio unit, and the converted signal is converted into a digital signal by AD conversion. This AD converted digital signal is subjected to high-speed signal processing equivalent to AD conversion by hardware. Examples of processing performed by this hardware include waveform shaping filter processing and despreading processing.
[0003]
The signal processed by the hardware is processed at a relatively low speed by the processor that operates according to the program at the transmission speed of the data before modulation on the transmission side (exactly, the error correction code is removed). . Examples of processing performed by this processor include interleave processing, error correction decoding processing, channel codec, and protocol processing.
[0004]
Note that since the processor is not limited to hardware, hardware that is not processed by executing a program is described as hardware in this specification.
[0005]
Here, the program read and executed by the processor is written in a non-rewritable storage area, and when supporting a plurality of radio communication systems such as software radio apparatuses, signal processing and protocols necessary for each radio communication system A program for performing processing and the like is recorded.
[0006]
When a program is recorded in a non-rewritable storage device in the wireless device, there is a merit that the program is not erased even when the power is turned off, but the program reading speed is very slow. For this reason, it is not suitable for a processor such as a DSP or CPU to directly read the program. Conversely, if a program is recorded in a rewritable storage device such as SRAM or DRAM that has a fast program reading speed in the wireless device, the program is erased when the power is turned off.
[0007]
For this reason, in the conventional wireless device, the program is copied from the non-rewritable storage device to the rewritable storage device every time the device is turned on.
[Patent Document 1]
Japanese Patent Laid-Open No. 11-274997 (FIG. 1)
[0008]
[Problems to be solved by the invention]
In such a conventional wireless device, it is necessary to copy a program from a non-rewritable storage device to a rewritable storage device each time the device is turned on. When the power is turned on, two identical programs exist so that the entire storage device As a result, there is a problem that the size and power consumption of the wireless device increase. Furthermore, since it takes time to copy the program, there is a problem that communication cannot be started immediately after the power is turned on.
[0009]
Further, when a multi-mode wireless device such as a software wireless device is realized with the wireless device having this configuration, two programs can be stored when attempting to switch programs for communication with another wireless communication system during communication. There was a problem that a rewritable storage device having a capacity of about a degree was necessary.
[0010]
An object of the present invention is to reduce the capacity of a memory. Another object of the present invention is to provide a wireless device with low power consumption.
[0011]
[Means for Solving the Problems]
In order to achieve the above object, according to the present invention, an antenna for transmitting and receiving a radio signal, a radio unit for filtering and frequency converting the radio signal received by the antenna to output a baseband analog signal, and An A / D converter that converts the baseband analog signal input from the radio unit into a digital signal, and a sampling speed of the A / D conversion for the digital signal converted by the A / D converter The hardware circuit that performs signal processing as described above, the first MRAM (Magnetic Resistive Random Access Memory) that stores the first program for communicating with the base station of the first wireless communication system, and the second wireless communication system A second MRAM for storing a second program for communicating with a base station of the By reading a program from the first or second MRAM and executing at least one of interleave processing, error correction decoding processing, channel codec, and protocol processing on a signal input from a hardware circuit A processor for processing, a data memory for storing data that needs to be temporarily stored in the course of execution of the program by the processor, and an inter-system handover from the first wireless communication system to the second wireless communication system In this case, there is provided a radio apparatus comprising switching means for switching a memory connected to the processor from the first MRAM to the second MRAM.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present embodiment will be described in detail with reference to the drawings.
(First embodiment)
FIG. 1 is a diagram showing a configuration of a first embodiment according to a radio apparatus of the present invention.
In FIG. 1, the wireless terminal 100 includes an antenna 101, a wireless unit 102, an AD / DA converter 103, and a modem LSI 110.
The antenna 101 receives a radio signal to be processed by the radio terminal 100 at the time of reception and outputs the radio signal to the radio unit 102, and transmits a signal processed by the radio terminal 100 as a radio signal at the time of transmission.
[0013]
The radio unit 102 processes the radio signal received by the antenna 101 at the time of reception, converts it to a baseband signal, outputs it to the AD / DA converter 103, and transmits the baseband signal input from the AD / DA converter 103 at the time of transmission. The analog signal is processed and output to the antenna 101.
[0014]
The AD / DA converter 103 converts a baseband signal that is an analog signal received by the wireless unit 102 into a digital signal at the time of reception and outputs the digital signal to the hardware circuit 112 in the modem LSI 110, and hardware at the modem LSI 110 at the time of transmission. The digital signal processed by the circuit 112 is converted into an analog signal and output to the wireless unit 102.
[0015]
The modem LSI 110 further includes a processor 111, a hardware circuit 112, a switching unit 113, a nonvolatile memory A 114, a nonvolatile memory B 115, and a volatile data memory 116.
[0016]
The hardware circuit 112 is hardware that processes a relatively high-speed radio signal such as a baseband signal input / output to / from the modem LSI 110.
The processor 110 performs radio signal processing by executing a program like a CPU or a DSP. The wireless signal processing is performed mainly up to the rate level of data demodulated from the wireless signal processed by the hardware circuit 112.
[0017]
The non-volatile memory A 114 has a high reading and writing speed and does not lose the written contents even when the power is turned off. For example, the non-volatile memory A 114 is an MRAM (Magnetic Resistant Random Access Memory). A program necessary for the processor to perform signal processing suitable for the wireless communication system A is written in the nonvolatile memory A114.
[0018]
This MRAM is a memory for storing data by magnetism, and has a characteristic that it is non-volatile and has a high read / write speed.
The non-volatile memory B115 is also a memory that has a high reading and writing speed and does not lose the written contents even when the power is turned off, for example, an MRAM. A program necessary for the processor to perform signal processing suitable for the wireless communication system B is written in the nonvolatile memory B.
[0019]
The volatile data memory 116 is a volatile memory, for example, a DRAM that can be read and written, but whose written contents are lost when the power is turned off. In the volatile data memory 116, intermediate data or demodulated data temporarily created in the process of digital signal processing is written while the processor 111 is executing a program.
[0020]
The switching unit 113 switches whether the processor 111 accesses the nonvolatile memory A114 or the nonvolatile memory B115, and is a bus bridge circuit, for example. The switching unit 113 performs switching every time one word is read or written.
[0021]
In this way, the switching means 113 can be switched for each word. The processor 111 has a memory for storing at least one word, which is a processing execution unit, in the processor 111. The processor 111 reads and writes data to and from the nonvolatile memory B115 during a period of reading and processing one word from the nonvolatile memory A114, thereby reading and executing the program from the nonvolatile memory A114 to the nonvolatile memory B115. Can read and write data.
[0022]
Next, the operation of the modem LSI 110 according to the present invention will be described in detail.
The processor 110 reads a program processed by itself from the nonvolatile memory A 114 or the nonvolatile memory B 115 and executes it.
As to whether the program is read from the nonvolatile memory A 114 or the nonvolatile memory B 115, the switching unit 113 stores the program from which the program was read last time, and the switching unit 113 stores the nonvolatile memory stored when the wireless terminal 100 is turned on. This is determined by connecting the volatile memory and the processor 111.
[0023]
When the wireless terminal 100 is in operation and the means for controlling the entire wireless terminal 100 determines that system handover is necessary, the switching means 114 switches the nonvolatile memory connected to the processor 111 to the other nonvolatile memory. In addition, this switching process may be performed by an instruction from the user (such as operating a predetermined button).
[0024]
The processor 111 performs signal processing suitable for the wireless communication system A according to the program in the nonvolatile memory A.
The radio signal received by the antenna 101 is subjected to frequency conversion, filter processing, and the like by the radio unit 102 to become a baseband signal. This baseband signal is converted into a digital signal by the AD / DA converter 103. The digital signal is subjected to high-speed digital signal processing by the hardware circuit 112, and then low-speed digital signal processing is performed by the processor 111.
[0025]
When executing a program suitable for the wireless communication system B stored in the non-volatile memory B115 while maintaining this communication, the switching unit 113 connects the non-volatile memory B115 and the processor 111, and the processor 111 Execution of the program recorded in the nonvolatile memory B115 is started.
[0026]
A case where the program in either the nonvolatile memory A 114 or the nonvolatile memory B 115 is changed to a new program during communication will be described.
Here, a description will be given assuming that the program stored in the nonvolatile memory B115 is newly rewritten to the program C of the wireless communication system C during communication by the wireless communication system A.
[0027]
The wireless terminal 100 performing communication by the wireless communication system A accesses a server where the program C is stored, for example, a server on the network of the wireless communication system A.
[0028]
Then, the program C is stored in the nonvolatile memory B115 using the line of the wireless communication system A. Alternatively, when the program C is overwritten in the non-volatile memory A 114 in which the program of the wireless communication system A is recorded, the program C is temporarily stored in the volatile data memory 116 and the connection with the wireless communication system A is terminated. The program C stored in the volatile data memory 116 is copied to the nonvolatile memory A.
[0029]
The processor 111 switches the switching means 113 for each minimum unit (one word) and accesses the nonvolatile memory A114 and the nonvolatile memory B115, thereby executing the program stored in the nonvolatile memory A114, The program C can be copied to the memory B115.
[0030]
As described above, the wireless device according to the present invention uses the MRAM, which is a memory having a high reading and writing speed and does not lose the written contents even when the power is turned off, as the nonvolatile memory A114 and the nonvolatile memory B115. There is no need to copy a program from a non-rewritable storage device to a rewritable storage device each time the device is turned on. For this reason, when the modem LSI 110 of the wireless terminal 100 is designed using the present invention, the amount of volatile memory can be greatly reduced as compared with the conventional modem LSI. Since the volatile memory consumes a large amount of power, the power consumption can be reduced.
[0031]
In addition, since the copying process from the rewritable ROM required to the conventional modem LSI to the volatile program memory is unnecessary, the startup time when the wireless terminal is turned on is shortened.
[0032]
Furthermore, even when a dynamic program change is required due to a request from the user or an automatic inter-system handover, a smooth and quick change can be made without interrupting the temporary communication.
[0033]
(Second Embodiment)
In the second embodiment, as shown in FIG. 2, the volatile data memory 116 in FIG. As the nonvolatile data memory 201, an MRAM is used. The operation and effect are the same as in the first embodiment, and the power consumption can be further reduced by eliminating the volatile memory.
[0034]
Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.
[0035]
【The invention's effect】
As described above, according to the present invention, the MRAM, which is a non-volatile memory that has a high reading and writing speed and does not lose the written contents even when the power is turned off, is used. Can be reduced.
[Brief description of the drawings]
FIG. 1 is a diagram for explaining a first embodiment of the present invention;
FIG. 2 is a diagram for explaining a second embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 100 ... Wireless terminal, 101 ... Antenna, 102 ... Radio | wireless part, 103 ... AD / DA converter, 110 ... Modem LSI, 111 ... Processor, 112 ... Hardware circuit, 113 ... Switching means, 114 ... Non-volatile memory A, 115 ... nonvolatile memory B, 116 ... volatile data memory, 201 ... nonvolatile data memory.

Claims (4)

An antenna for transmitting and receiving radio signals;
A radio unit that outputs a baseband analog signal by performing filter processing and frequency conversion on the radio signal received by the antenna;
An A / D converter that converts the baseband analog signal input from the wireless unit into a digital signal;
A hardware circuit that performs signal processing on the digital signal converted by the A / D converter at a sampling speed higher than the sampling speed of the A / D conversion;
A first MRAM (Magnetorative Random Access Memory) that stores a first program for communicating with a base station of a first wireless communication system;
A second MRAM for storing a second program for communicating with a base station of the second wireless communication system;
Reading a program from the first or second MRAM and executing at least one of interleave processing, error correction decoding processing, channel codec, and protocol processing on a signal input from the hardware circuit A processor for processing by:
A data memory for storing data that needs to be temporarily stored in the course of execution of the program by the processor;
A switching means for switching a memory connected to the processor from the first MRAM to the second MRAM when an inter-system handover is performed from the first wireless communication system to the second wireless communication system; A wireless device characterized by the above. Furthermore, it has a receiving means for receiving an instruction for handover between systems by the user,
The radio apparatus according to claim 1, wherein the switching unit switches a memory connected to the processor from the first MRAM to the second MRAM in response to the instruction received by the receiving unit. . 2. The apparatus according to claim 1, further comprising control means for causing the processor to read and execute the first program and to store the second program input from the outside in the second MRAM. Or the radio | wireless apparatus of 2. The wireless device according to claim 1, wherein a nonvolatile memory is used as the data memory.

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