JP2006313993A - Ultrawideband load-distributed wireless communication method and system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ultrawideband load-distributed wireless communications system capable of realizing efficient throughput over whole radio stations and the whole communications system by developing a wireless access system by which loads are distributed to a plurality of radio frequency channels with an ultrawide waveband. <P>SOLUTION: The ultrawideband load-distributed wireless communication system, wherein a plurality of wireless stations share a radio space configured with different radio frequency channels at a plurality of bands includes a means 6 that searches a radio frequency channel usable over a wide band for the wireless stations and detects a channel state of the radio frequency channel by analyzing the received signal; a means 7 of distributing transmission data to each radio frequency channel, on the basis of the channel state; and means 8, 9 for selecting a proper transmission data rate variable modulation system for supplementing a difference between the transmission qualities and transmittable data rates between different wireless links to modulate a transmission signal. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an ultra-wideband load-distributed radio communication method that uses a plurality of radio frequency channels of different bands and transmits one information signal while distributing the load to each radio frequency channel between radio stations. It is a technology concerning.

  In recent years, it is not uncommon for mobile terminals to have multiple wireless interfaces. For example, a technology has been studied in which a mobile terminal equipped with an interface for wireless LAN and cellular communication is switched from wireless LAN to cellular communication seamlessly as usage scenes change. Such a handover is called a vertical handover with respect to a conventional handover between cells (horizontal handover).

  In particular, the frequency band below the microwave band has good radio wave propagation characteristics and is a convenient frequency band for mobile communications, so it is used in many systems under frequency management with sufficient legal development. However, the frequency tightness is a problem. However, as the frequency becomes higher, the radio wave increases straight and does not reach far away, and depending on the shielding situation such as an obstacle, a lot of available frequency bands are generated in a certain space (location).

Therefore, in the ultra wide frequency band from the microwave band to the millimeter wave band, the terahertz wave, and the optical frequency band, a free frequency band that can be used autonomously by the wireless terminal and a frequency band that can be expected to be used even during use are detected temporarily. It is considered possible to use it.
In the case of handover, switching from one of the radio frequency band channels to a different channel is performed. However, even if communication in the original radio frequency band channel is still possible with this method, basically all communication is performed. Switch to a new channel. Therefore, there is a possibility that the original channel resource is wasted.

  Therefore, a system is considered in which a single information signal is transmitted and received over a very wide frequency band by using a plurality of radio frequency band channels that can be used at that location, instead of switching channels by handover. However, in such a system, between different frequency channels determined to be usable by the terminal's own analysis, the channel quality depends on the available frequency band, the interference status of other wireless terminals, the propagation environment, etc. Since the situation and the like are different, an access method is required that complements or equalizes the difference between the transmission quality generated between different channels and the transmittable data rate.

Since the conventional technique has not provided such an access method, it has been impossible to efficiently use a plurality of radio frequency band channels simultaneously.
The conventional proposed method does not provide a method for transmitting and receiving a load while distributing and simultaneously using multiple channels adaptively, and does not provide a resource (communication capacity, mainly communication capacity) in a radio station. For example, Patent Literature 1 discloses a technique for distributing the load on the baseband signal processing means.

JP 2004-120070

  The present invention has been created in view of the above-described problems of the prior art, and has developed a wireless access method in which a load is distributed over a plurality of ultra-wideband radio frequency channels. An object of the present invention is to provide an ultra-wideband load-distributed radio communication system capable of realizing a typical throughput.

In order to solve the above problems, the present invention has the following means.
That is, the radio station of the present invention autonomously searches for a vacant frequency in the place like a cognitive radio, but this is performed on the peripheral space of the radio station over a very wide frequency band, and each frequency is In addition to the function of detecting the usage status of the band, this is analyzed, and the signal to be transmitted is distributed (load distribution) to the optimal transmission frequency channel for transmission. With this configuration, the maximum throughput according to the location is obtained at that time, and the maximum throughput per unit space is realized even when viewed in the entire network society.

The invention according to claim 1 is an ultra-wideband load distribution type radio communication method that uses a plurality of radio frequency channels of different bands and transmits one information signal while distributing the load among the radio frequency channels between radio stations. And the following steps are provided.
(1) A receiving step in which the receiving means of the radio station receives and demodulates the received signal for each radio frequency channel;
(2) A channel status detection analysis step in which the channel status detection / analysis means of the radio station detects each available radio frequency channel and detects the status of the channel determined to be available by analyzing the received signal.
(3) The load distribution means of the radio station synthesizes the received signals from the respective frequency channels and outputs the received data, and determines the ratio of allocating the transmission data to the respective radio frequency channels based on the channel status. , A load distribution step for dividing and distributing the transmission data for transmission in each radio frequency channel;
(4) Variable transmission rate modulation means for selecting a suitable transmission rate variable modulation method for compensating for the difference in transmission quality and transmittable data rate between different radio frequency channels by the variable data rate modulation means of the radio station. Modulation step,
(5) The transmission means of the radio station has each step of a transmission step in which the channel status data detected by the channel status detection analysis means is added to the transmission signal load-distributed for each radio frequency channel and transmitted. Features.

  According to a second aspect of the present invention, in the transmission rate variable modulation step, the data rate variable modulation means performs modulation after encoding processing for performing error correction encoding with different coding rates independently in each radio frequency channel. It is characterized by doing.

  The invention according to claim 3 is characterized in that, in the variable transmission rate modulation step, the variable data rate modulation means performs different modulation independently in each radio frequency channel after a predetermined encoding process.

  According to a fourth aspect of the present invention, in the transmission rate variable modulation step, the data rate variable modulation means has a direct spreading type or frequency hopping type code division multiplexing (having a variable spreading factor structure after a predetermined encoding process). A VSF-CDM) method is used, and a spreading factor in the modulation method is changed according to a channel condition to be used.

  According to a fifth aspect of the present invention, in the variable transmission rate modulation step, the variable data rate modulation means uses a variable spreading factor / orthogonal frequency code division multiplexing (VSF-OFCDM) method after a predetermined encoding process, The method is characterized in that the spreading factor in the modulation scheme is changed according to the channel condition to be used.

The invention according to claim 6 of the present invention uses an ultra-wideband load sharing type radio communication that uses a plurality of radio frequency channels of different bands and transmits one information signal while distributing the load among the radio frequency channels between radio stations. Provide a system.
The system realizes peer-peer communication between any wireless stations while spatially sharing a plurality of different radio frequency channels of different bands available for communication among the plurality of wireless stations.

  Then, the radio station receives a reception signal for each radio frequency channel and demodulates it, searches for each available radio frequency channel, and analyzes the status of the channel determined to be usable by analyzing the received signal. Channel condition detection and analysis means for detecting and synthesizing received signals from each frequency channel and outputting received data, while determining the amount of transmission in each radio frequency channel based on the channel condition, and transmitting data to each radio frequency Load distribution means for allocating to channels, data rate variable modulation means for selecting an appropriate transmission rate variable modulation method that complements the difference between transmission quality and transmittable data rate between different radio frequency channels, and modulating the transmission signal, The channel status data detected by the channel status detection and analysis means is attached to the transmission signal load-balanced for each radio frequency channel. Characterized by comprising a transmitting means for sending to.

  The invention according to claim 7 is characterized in that the data rate variable modulation means modulates after the encoding processing for performing error correction encoding at different coding rates independently in each radio frequency channel.

  The invention according to claim 8 is characterized in that the variable data rate modulation means performs different modulation independently in each radio frequency channel after a predetermined encoding process.

  The data rate variable modulation means uses a direct spreading type or frequency hopping type code division multiplexing (VSF-CDM) system having a spreading factor variable structure after a predetermined encoding process. In other words, modulation using a different spreading factor is performed independently for each radio frequency channel.

  According to a tenth aspect of the present invention, the variable data rate modulation means uses a spreading factor variable / orthogonal frequency code division multiplexing (VSF-OFCDM) method after a predetermined encoding process, and uses a spreading factor (VSF-OFCDM) in the modulation method. At the same time that the spreading factor is changed, different values are used independently for the number of subcarriers used for transmission.

  The invention according to claim 11 can provide a radio station of the radio communication system. That is, the radio station of the present invention receives a reception means for receiving and demodulating a received signal for each radio frequency channel, searches for available radio frequency channels, and receives the line status of each radio frequency channel determined to be usable. Channel condition detection and analysis means for detecting by signal analysis, and combining each received signal and outputting received data, while determining the transmission amount in each radio frequency channel based on the channel condition and transmitting data to each radio frequency Load distribution means for allocating to channels, variable data rate modulation means for selecting a transmission rate variable modulation method that complements the difference between transmission quality and transmittable data rate between different radio frequency channels, and modulating the transmission signal, and each radio Transmission means for transmitting a transmission signal in which channel state information is added to transmission data for each frequency channel To.

  In addition, a radio station can be provided in each of the embodiments constituting the data rate variable modulation means as described above.

  In the radio station of the radio communication system according to the present application, the receiving means for receiving and demodulating the received signal, and the channel for detecting the channel status of the radio frequency channel used for reception by analyzing the received signal A situation detecting / analyzing means; a coding / modulating means for performing transmission data modulation comprising an adaptive coding section for changing a coding rate in error correction coding in relation to the channel situation; and a sending means for transmitting a transmission signal; It is also possible to provide a radio station equipped with

By the above means, the present invention has the following effects.
In other words, from the viewpoint of a wireless station, instead of simply switching (handing over) the channel that is always used to the optimal wireless channel, the load is distributed and a single information channel is sent and received. At the same time, transfer of the same amount of information can be completed in a short time.

  In addition, since the terminal searches for and uses a vacant frequency in an autonomous and distributed manner, the frequency can be effectively used more densely in space.

  In an ad hoc network (ubiquitous network) formed by considering each wireless terminal as an ad hoc terminal having an exchange function, each wireless terminal can use any available wireless channel without wasting it. Since it works in an autonomous and distributed manner, the network capacity increases and the amount of traffic that can be handled by the entire network increases when viewed from a terminal that intends to use the terminal as a relay node.

  Even when a new load generating terminal occurs in the network, each terminal controls the load distribution state for the channel in an autonomous and distributed manner, so that it converges to a certain optimal network state. As a result, it is possible to contribute to a wireless communication system that can always dynamically maintain an optimal communication state.

Hereinafter, embodiments of the present invention will be described based on examples shown in the drawings. The embodiment is not limited to the following.
FIG. 1 and FIG. 2 are aspects of an ultra-wideband load sharing type wireless communication system according to the present invention. The system of FIG. 1 is terminal-to-access point communication, and there are radio channel spaces A to C in a plurality of frequency bands between the two.

2 is multipoint-to-multipoint communication in a ubiquitous wireless network, and there are radio channel spaces A to C in a plurality of frequency bands between them.
The present invention is effective in any of the above-described configurations. In particular, in the configuration of FIG. 2, the traffic of the entire network can be increased.

Hereinafter, a technique for using a plurality of wireless communication channels in a wireless station will be disclosed. Different frequency channels that are determined to be usable by analysis of the radio station differ in usable frequency bandwidth, interference with other radio terminals, and line conditions depending on the propagation environment.
Therefore, when data to be transmitted is distributed to different channels in a load-sharing manner and simultaneously transmitted, there is an access method that can simultaneously handle different transmittable rates while compensating for the difference in transmission quality that occurs between channels. Necessary.

Therefore, in the present invention, (a) a state detection technique for each channel, (b) a transmission signal (load) distribution technique based on the detection information, and (c) a distributed signal is modulated by a method suitable for the channel condition. The above access method is provided by three technologies.
That is, first, the receiving means of the radio station receives and demodulates the received signal for each radio frequency channel (receiving step).

As a technique of (a), the channel status detection / analysis means detects the channel status of each available radio frequency channel by analyzing the received signal (channel status detection analysis step).
The channel state detection / analysis means can use a known method for detecting the line state. For example, if an unused frequency channel is first searched, the reception level is obtained by analyzing the frequency of a signal received in a wide band. Is detected, or the channel with the lowest detection level can be determined as an unused channel. In order to detect the situation of the frequency channel assumed to be used, for example, FCS (frame check sequence) is added to the signal frame to be transmitted and received, and the error is detected on the receiving side based on this by detecting the frame error. This is possible by analyzing the error rate.

  As a technique of (b), the transmission amount of each used channel is determined based on the channel state detection analysis step, and load distribution based on this is performed (load distribution step). Regarding the method of distributing the amount of transmission, for example, if data transmission is considered as a routing node connected to a plurality of transmission paths and a wireless station is learned from load distribution technology in existing communication between routing nodes, load distribution processing The error rate of the channel obtained in the above-mentioned channel condition detection and analysis step as a cost value calculation for performing non-uniform load distribution using the Enhanced Interior Gateway Routing Protocol (EIGRP), which is a well-known technology as a routing protocol having the function of Is considered as this cost value. Then, by combining the technique (c) described later, a method of performing load distribution or the like so that the error rate in all channel transmissions is the most uniform can be considered.

  Similarly, for example, in combination with the technique of (c), variable modulation parameters for determining transmission capacity are sequentially assigned from channels with poor error conditions, and the variable modulation parameters are reduced until the required frame error rate is reached. A method of giving a feedback instruction to the transmission side can be considered.

  A feature of the present invention is that the transmission data is divided and distributed based on the capacity of each transmittable channel and then transmitted to the destination terminal with the same quality. A known method can be used for. For example, a layer 2 ether packet may be distributed at a desired distribution ratio, or a layer 3 IP packet may be distributed at a desired distribution ratio.

Further, as a technique of (c), the data rate variable modulation means of the radio station selects a transmission rate variable modulation method that complements the difference between the transmission quality between different radio frequency channels and the transmittable data rate, and modulates the transmission signal. (Transmission rate variable modulation step). In complementation, it is necessary to consider that the available frequency band differs depending on the channel used, the link margin such as signal reception level attenuation caused by the propagation environment is different, and the amount of interference is different.
Finally, the transmitting means of the radio station transmits a transmission signal for each radio frequency channel, but the receiving radio station comprehensively understands the status of each radio channel, and is provided by the technique (a). The channel information obtained in the channel status detection analysis step is added to the transmission data and transmitted (transmission step).

As described above, the present application has realized the wireless access method by the combination of the above (a) to (c), particularly the technology (c), which will be described in detail below.
As the first embodiment, the traffic distributed for different transmission frequency channels is subjected to error correction coding (Feed forward error correction) at different coding rates and transmitted independently. A method for compensating for the difference in transmission quality between channels and the transmittable data rate is provided.

FIG. 3 shows a block diagram of the radio station in the first embodiment. This configuration is a radio station that performs error correction processing with different coding rates adaptively to baseband signals.
In this radio station, a receiving unit (3) and a transmitting unit (4) are provided for each of the radio communication channels of a plurality of channels # 1 (1) to #N (2). The received signal received by the receiving unit (3) is input to the demodulator (5) and demodulated.

Further, the analyzer (6) analyzes the FCS and analyzes the error rate. The received signal from each channel (1) (2) is input to the signal distribution processor (7) and the received data is output. At the same time, the analysis result of the FCS is added to the transmission data of the channel and transmitted. Sent as a signal.
The transmission data is first input to the signal distribution processor (7) and distributed to each channel. As described above, for distribution, error information of the channel in the analyzer (6) and how erroneously the receiving station has received data received from each channel using the channel is received. The signal distribution processing circuit determines from the channel error information and distributes it. The distribution method may be defined in advance by the error rate, and the distribution amount may be determined accordingly, or determined by simultaneously selecting the transmission rate variable modulation method in (c) so that the same error rate is obtained in all channels. May be. This is because many transmission rate variable modulation systems exemplified in the present application are related to whether the number of errors in the transmission path increases as the transmission rate is increased.

  The distributed transmission data is input to the adaptive encoder (8) according to the present invention. In this adaptive encoder, the coding rate is controlled so that the transmission rate becomes a fixed transmission rate. For the adaptive encoder (8), for example, Puncturing control in a convolutional encoder is suitable. In other words, in the case of a convolutional encoder with a coding rate of 1/2, 4 redundant bits are added to a relatively 4-bit input to obtain a total of 8 bits of output. An output with an appropriate coding rate can be obtained by thinning out (Puncturing). That is, by controlling this puncturing, a desired coding rate can be obtained.

In addition, a BCH code, a turbo code having a high error correction capability, a Woven code, or an LDPC code can be used for the adaptive encoder.
In each channel, the channel status information corresponding thereto is added to the transmission data with the data indicated by the load distribution signal processing device (7), then encoded, modulated by the modulator (9), and transmitted by the transmitter (4). Send from.
As described above, in this embodiment, the modulation / demodulation method is fixed, and the adaptive encoder controls the coding rate so that the signal distributed by the load sharing signal processing becomes a fixed transmission rate at the transmission stage, and is transmitted. .

  According to the configuration of the first embodiment, the method of performing error correction processing of adaptively different coding rates on a signal whose load is distributed in the baseband region is basically a minimum modification to the RF modulation / demodulation unit, and the base This method can be applied by changing only the signal processing unit in the band.

Next, a second embodiment of the present invention will be described. In this embodiment, traffic distributed for different transmission frequency channels is transmitted independently by RF carriers using different modulation schemes, so that transmission quality between different channels and transmittable data rate can be improved. It is a way to compensate for the difference.
FIG. 4 shows the configuration of a radio station according to the present embodiment. Constituent elements similar to those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

  In this embodiment, an adaptive modulator (10) is used instead of the adaptive encoder and modulator. The adaptive modulator (10) performs modulation by a modulation method suitable for the transmission rate of the signal distributed by load sharing signal processing. Although not shown, in this embodiment, an encoder with a fixed coding rate is arranged between the signal distribution processor (7) and the adaptive modulator (10).

  To change the modulation method, there is a method of adaptively switching between BPSK, WPSK, 8PSK, 16QAM, 64QAM, 128QAM, 256QAM, and even 1024QAM while the output symbol rate (occupied band) of the adaptive modulator (10) remains the same. . As a result, the transmission rate can be made variable and the tolerance against errors in each channel can be controlled.

  In the third embodiment of the present invention, traffic distributed for different transmission frequency channels is transmitted independently by RF carriers using the VSF-CDM modulation method, and the spreading factor (Spreading Factor) is used. ) To compensate for the difference in transmission quality between different channels and the transmittable data rate.

FIG. 5 is a configuration diagram of a radio station in the present embodiment.
In this configuration, a primary modulator (11) and a secondary modulator (12) are provided, and the spreading factor is changed in the primary modulator (11). This configuration uses variable spreading factor / code division multiplex modulation (VSF-CDM) with variable expansion rate based on direct spreading CDM method using a fixed chip rate, and the frequency band required for the radio link is Only the resistance to interference can be controlled while being fixed. That is, the spreading factor is set low for a channel with a low interference level and high transmission capacity can be expected, and conversely, the spreading factor is set large for a channel with a low transmission capacity.
Since this method is a CDM system, it can be expected to suppress interference signals using different code sequences (signals from radio stations that are not supposed to be received).

FIG. 6 shows the signal waveform in the high-speed transmission data in the upper stage, and the signal waveform in the low-speed transmission data in the lower stage. High-speed data transmission is when the interfered signal level is low, and low-speed data transmission is when the level is high.
This figure shows a state where a double different transmission rate is realized by using a fixed chip rate and a fixed spreading code. Since the modulation method is simple, direct diffusion using a bipolar signal of a BPSK signal is assumed.

In the upper part of FIG. 6, 2 bits are transmitted per spreading code, whereas only 1 bit is transmitted in the lower part, so the information transmission rate is halved.
However, the interference suppression effect is improved because the lower stage spreads the signal twice. In this way, by increasing or decreasing the number of bits transmitted in one spreading code sequence, it is possible to control the link transmission rate and error resistance.

  As another form of the third embodiment, a radio station provided with a variable data rate primary modulator (13) and a pattern variable frequency hopping synthesizer (14) as shown in FIG. 7 can be provided. A configuration that can control the transmission rate and the tolerance to interference while maintaining the physical transmission band required for the radio link by making the output by the spread spectrum method using the pattern variable frequency hopping synthesizer within a fixed frequency range It is possible to take

  In this case, the data rate variable primary modulation scheme is preferably a method of adaptively increasing or decreasing the number of subcarriers to be used, for example, using a wideband OFDM modulation / demodulation scheme, rather than a symbol rate variable modulator / demodulator. FIG. 8 shows the adaptation status (spectrum) of a radio station according to the present invention when the interference level of a link to be communicated within the allocated band is large (upper stage) and small (lower stage).

In the upper stage (links with a large level of interference), the transmission rate (number of subcarriers used) is reduced, and this is sufficiently frequency-hopped (frequency spread) over a relatively wide band to increase the immunity to interference. Can be transmitted.
In the lower stage (link with a small level of interference), the transmission rate (number of subcarriers used) is increased for transmission, so the spreading factor due to frequency hopping (frequency spreading) decreases and interference resistance is sacrificed. ing.
In the most extreme case (link with non-interference level 0), transmission is possible as a link with a spreading factor of 1. In other words, frequency hopping is not performed at all and all usable bands are always used for signal transmission.

  Finally, as Example 4 of the present invention, traffic distributed for different transmission frequency channels is transmitted independently by RF carriers using the VSF-OFCDM modulation method, and the expansion rate (Spreading) Describes how to compensate for differences in transmission quality and transmittable data rate between different channels by controlling Factor. Note that it is possible to control the physical occupied frequency band by controlling the number of subcarrier frequencies used in the modulation scheme.

FIG. 9 shows a configuration diagram of a radio station in the present embodiment. This radio station includes a VSF-OFCDM modulator (15).
Since this configuration is based on the VSF-OFCDM system, the frequency band required for each radio channel remains constant, and the frequency utilization efficiency is greatly improved. There are only features that can be adapted.

  Specifically, the signal distributed by the load distribution process is modulated using a VSF-OFCDM modulator and transmitted. For a channel with a high transmission capacity, the spreading factor (spreading factor) is set to a small value. Conversely, for a channel with a low transmission capacity, the spreading factor is set to a large value. In addition, because it is a CDM system, it can be expected to suppress interference signals (signals from radio stations that are not supposed to be received) using different code sequences, and at the same time, it is an OFDM system. The line margin can be changed by changing. It is also easy to change the used frequency bandwidth by changing the number of used subcarriers.

  FIG. 10 is a block diagram of the VSF-OFCDM modulator, and FIG. 12 is the demodulator. Although the modulator / demodulator of the VSF-OFCDM is known, it has the Variable SF controller (spreading rate adjusting unit) (20) in FIG. 10, and adjusts the spreading rate by the control from the analyzer (6). At this time, by controlling the Spreading Factor (frequency domain, time domain) shown in FIG. 11, it is possible to arbitrarily set the transmission rate and the tolerance to interference.

  The basic configuration and operation of the VSF-OFCDM modulator and demodulator are already well known but will be briefly outlined. Input data is appropriately encoded by a channel encoder and then converted to a data stream appropriately modulated by a data modulator. This is converted into a plurality of data series by a serial / parallel conversion circuit and then interleaved by an interleaver. If the data sequence obtained here is converted by IFFT and parallel / serial converted, and a guard interval is added, it becomes a normal OFDM signal. However, in VSF-OFDM, each data sequence before IFFT conversion is processed as desired. After preparing data copied by the spreading factor in the frequency direction, the code sequence from the spreading code generator is further multiplied and code-multiplexed. The frequency spreading factor can be controlled by controlling the number of copies in the frequency spreading direction at this time. Also, the time spreading factor can be controlled by controlling the code generator output. The operation of the demodulator is omitted because it is mainly the reverse operation of the modulator based on the operation of the OFDM demodulator.

According to this method, even when a new interference station is generated, each wireless station can control parameters for variable transmission data rate modulation in an autonomous and distributed manner so that it can converge to the best network state that does not waste frequency resources. Is possible.
Further, since the methods of Embodiments 2 to 4 are executed by load sharing transmission processing combined with the RF modulation method, it contributes to high-speed and low-delay processing, and a wide range of transmission efficiency parameters can be selected.

1 is an overall configuration diagram of a wireless communication system example 1 according to the present invention. It is a whole block diagram of the radio | wireless communications system example 2 by this invention. It is a block diagram of the radio station which concerns on Example 1 of this invention. It is a block diagram of the radio station which concerns on Example 2 of this invention. It is a block diagram of the radio station which concerns on Example 3 (the 1) of this invention. It is a signal waveform in the same Example. It is a block diagram of the radio station which concerns on Example 3 (the 2) of this invention. It is a signal spectrum in the same Example. It is a block diagram of the radio station which concerns on Example 4 of this invention. It is a block diagram of a VSF-OFCDM modulator according to the same embodiment. It is explanatory drawing explaining how to define a spreading | diffusion rate parameter. It is a block diagram of the VSF-OFCDM demodulator according to the same embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Received signal 2 Transmitted signal 3 Receiver 4 Transmitter 5 Demodulator 6 Analyzer 7 Signal distribution processor 8 Adaptive encoder

Claims (16)

A wireless communication method of an ultra-wideband load sharing type using a plurality of radio frequency channels of different bands and transmitting one information signal while distributing the load to each radio frequency channel between radio stations,
A receiving step in which the receiving means of the radio station receives and demodulates the received signal for each radio frequency channel;
A channel status detection analysis step in which the channel status detection analysis means of the radio station detects each available radio frequency channel and detects the status of the channel determined to be available by analyzing the received signal;
The load distribution means of the radio station synthesizes the received signals from the respective frequency channels and outputs the received data, while determining the ratio of allocating the transmission data to the respective radio frequency channels based on the channel status, A load distribution step for dividing and allocating data for transmission in each radio frequency channel;
A transmission rate variable modulation step in which the data rate variable modulation means of the radio station selects an appropriate transmission rate variable modulation method that complements the difference in transmission quality and transmittable data rate between different radio frequency channels and modulates the transmission signal.
The transmission means of the radio station includes each step of a transmission step of adding the channel status data detected by the channel status detection analysis means to the transmission signal load-distributed for each radio frequency channel and transmitting it. Ultra-wideband load sharing wireless communication method. 2. The ultra-wideband load distribution according to claim 1, wherein in the transmission rate variable modulation step, the data rate variable modulation means performs modulation after encoding processing for performing error correction encoding at different coding rates independently in each radio frequency channel. Type wireless communication method. The ultra-wideband load-distributed radio communication method according to claim 1, wherein in the variable transmission rate modulation step, the variable data rate modulation means performs different modulation independently for each radio frequency channel after a predetermined encoding process. In the transmission rate variable modulation step, the data rate variable modulation means uses a direct spreading type or frequency hopping type code division multiplexing (VSF-CDM) system having a spreading factor variable structure after a predetermined encoding process. The ultra-wideband load sharing type radio communication method according to claim 1, wherein modulation is performed using a different spreading factor independently for each radio frequency channel. In the transmission rate variable modulation step, the data rate variable modulation means uses a variable spreading factor / orthogonal frequency code division multiplexing (VSF-OFCDM) method after a predetermined encoding process, and in each radio frequency channel The ultra-wideband load-distributed radio communication method according to claim 1, wherein different spreading factors are used independently, and modulation is performed using different values for the number of subcarriers used for transmission. An ultra-wideband load sharing type radio communication system that uses a plurality of radio frequency channels of different bands and transmits one information signal while distributing the load among radio frequency channels between radio stations,
Multiple radio stations share multiple radio frequency channels with different propagation conditions and bands available for communication,
The radio station
Receiving means for receiving and demodulating the received signal for each radio frequency channel;
Channel status detection analysis means for detecting each available radio frequency channel and detecting the status of the channel determined to be usable by analyzing the received signal;
Load distribution means for combining the received signals from each frequency channel and outputting the received data, determining the transmission amount in each radio frequency channel based on the channel status, and allocating the transmission data to each radio frequency channel;
Data rate variable modulation means for selecting an appropriate transmission rate variable modulation method that complements the difference between transmission quality and transmittable data rate between different radio frequency channels and modulating the transmission signal,
An ultra-wideband load-distributed radio communication system comprising: a transmission means for adding the channel status data detected by the channel status detection analysis means to a transmission signal load-distributed for each radio frequency channel; . The ultra-wideband load-distributed radio communication system according to claim 6, wherein the data rate variable modulation means performs modulation after encoding processing for performing error correction encoding at different coding rates independently in each radio frequency channel. The ultra-wideband load-distributed radio communication system according to claim 6, wherein the data rate variable modulation means performs different modulation independently in each radio frequency channel after a predetermined encoding process. The data rate variable modulation means uses a direct spreading type or frequency hopping type code division multiplexing (VSF-CDM) system having a variable spreading factor structure after a predetermined encoding process, and each radio frequency channel The ultra-wideband load-distributed radio communication system according to claim 6, wherein modulation using a different spreading factor is performed independently for each. The variable data rate modulation means uses a variable spreading factor / orthogonal frequency code division multiplexing (VSF-OFCDM) method after a predetermined encoding process, and uses a different spreading factor for each radio frequency channel independently. At the same time, the ultra-wideband load-distributed radio communication system according to claim 6, wherein modulation is performed using different values independently for the number of subcarriers used for transmission. A radio station of an ultra-wideband load distribution type radio communication system that uses a plurality of radio frequency channels of different bands and transmits one information signal while distributing the load to each radio frequency channel between radio stations,
Receiving means for receiving and demodulating the received signal for each radio frequency channel;
Channel status detection and analysis means for detecting each available radio frequency channel and detecting the status of the channel determined to be usable by analyzing the received signal;
Load distribution means for combining received signals from each frequency channel and outputting received data, determining a transmission amount in each radio frequency channel based on the channel status, and allocating transmission data to each radio frequency channel;
Data rate variable modulation means for selecting an appropriate transmission rate variable modulation method that complements the difference between transmission quality and transmittable data rate between different radio frequency channels and modulating the transmission signal,
An ultra-wideband load-distributed radio communication system comprising: a transmission means for adding the channel status data detected by the channel status detection analysis means to a transmission signal load-distributed for each radio frequency channel; Radio stations. The radio station of the ultra-wideband load-distributed radio communication system according to claim 11, wherein the data rate variable modulation means performs modulation after encoding processing for performing error correction encoding at different coding rates independently in each radio frequency channel. . The radio station of the ultra-wideband load distribution type radio communication system according to claim 11, wherein the data rate variable modulation means performs different modulation independently in each radio frequency channel after a predetermined encoding process. The data rate variable modulation means uses a direct spreading type or frequency hopping type code division multiplexing (VSF-CDM) system having a variable spreading factor structure after a predetermined encoding process, and each radio frequency channel The radio station of the ultra-wideband load distribution type radio communication system according to claim 11, wherein modulation using a different spreading factor is performed independently for each. The variable data rate modulation means uses a variable spreading factor / orthogonal frequency code division multiplexing (VSF-OFCDM) method after a predetermined encoding process, and uses a different spreading factor for each radio frequency channel independently. The radio station of the ultra-wideband load-distributed radio communication system according to claim 11, wherein at the same time, modulation using different values is independently performed for the number of subcarriers used for transmission. In a radio station of a radio communication system,
Receiving means for receiving and demodulating the received signal;
Channel status detection and analysis means for detecting the channel status of the radio frequency channel used for reception by analyzing the received signal;
Coding modulation means for performing transmission data modulation comprising an adaptive coding section for changing a coding rate in error correction coding in relation to the channel situation;
A radio station of a radio communication system, comprising: a transmission means for transmitting a transmission signal.