US20020016156A1 - Diversity wireless communication method and its wireless communication apparatus - Google Patents
Diversity wireless communication method and its wireless communication apparatus Download PDFInfo
- Publication number
- US20020016156A1 US20020016156A1 US09/930,977 US93097701A US2002016156A1 US 20020016156 A1 US20020016156 A1 US 20020016156A1 US 93097701 A US93097701 A US 93097701A US 2002016156 A1 US2002016156 A1 US 2002016156A1
- Authority
- US
- United States
- Prior art keywords
- data
- received data
- received
- encoding
- radio channel
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03M—CODING; DECODING; CODE CONVERSION IN GENERAL
- H03M13/00—Coding, decoding or code conversion, for error detection or error correction; Coding theory basic assumptions; Coding bounds; Error probability evaluation methods; Channel models; Simulation or testing of codes
- H03M13/03—Error detection or forward error correction by redundancy in data representation, i.e. code words containing more digits than the source words
- H03M13/05—Error detection or forward error correction by redundancy in data representation, i.e. code words containing more digits than the source words using block codes, i.e. a predetermined number of check bits joined to a predetermined number of information bits
- H03M13/13—Linear codes
- H03M13/132—Algebraic geometric codes, e.g. Goppa codes
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03M—CODING; DECODING; CODE CONVERSION IN GENERAL
- H03M13/00—Coding, decoding or code conversion, for error detection or error correction; Coding theory basic assumptions; Coding bounds; Error probability evaluation methods; Channel models; Simulation or testing of codes
- H03M13/03—Error detection or forward error correction by redundancy in data representation, i.e. code words containing more digits than the source words
- H03M13/05—Error detection or forward error correction by redundancy in data representation, i.e. code words containing more digits than the source words using block codes, i.e. a predetermined number of check bits joined to a predetermined number of information bits
- H03M13/13—Linear codes
- H03M13/15—Cyclic codes, i.e. cyclic shifts of codewords produce other codewords, e.g. codes defined by a generator polynomial, Bose-Chaudhuri-Hocquenghem [BCH] codes
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
- H04B7/022—Site diversity; Macro-diversity
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
- Y02D30/00—Reducing energy consumption in communication networks
- Y02D30/70—Reducing energy consumption in communication networks in wireless communication networks
Abstract
In the conventional diversity reception, information included in each non-selected signal does not contribute to an improvement in the reliability of communications, and transmitting power has been dissipated to satisfy required communication quality. Owing to the setting of encoding in respective base stations to injection, signals each including the same contents, which are received by a mobile station, are used for increasing the reliability of communications without depending on the number of the signals which were capable of being received by the mobile station, to thereby reduce transmitting power for satisfying required communication quality.
Description
- The present invention relates to a mobile wireless communication system. The present invention also relates particularly to a diversity wireless transmitting/receiving system for transmitting data each including the same contents from a plurality of transmitting stations and performing diversity reception of the data by a receiving station.
- In a mobile communication in which communications are conducted between base stations and a mobile station, a system has been adopted in which the mobile station performs diversity reception of signals each including the same contents from a plurality of the neighboring base stations. As one example of this type of diversity reception system, Japanese Patent Laid-open (Kokai) No. Hei 5-83181 discloses a system wherein an error check is made to each of a plurality of received signals identical in contents and one signal determined to be free of an error is selected.
- In the aforementioned conventional system, information included in each signal non-selected as a result of the error check does not contribute to an improvement in the reliability of communications. As a result, transmitting power has been dissipated to satisfy required communication quality.
- In the present invention, such a configuration that information included in all the signals to be selected can be effectively utilized, is adopted to reduce transmitting power for satisfying required communication quality. Described specifically, respective base stations respectively transmit those obtained by dividing a code word in an error correcting code, and a mobile station combines fragments of the divided code words and decodes the combined one, thereby bringing information to a high degree of reliability. The following problems arise at this time.
- Upon firstly establishing the mobile communication, the existing locations of a mobile station are roughly divided into the two as follows:
- (1) when the mobile station exists in a location where it can receive signals with suitable intensity from a plurality of base stations due to reasons such as the passage of the mobile station through a point located midway between the plurality of base stations.
- (2) when the mobile station exists in a location where it is able to receive a signal with sufficient intensity from a given base station but unable to receive signals with suitable intensity from other base stations due to the reason that it is far distant therefrom, for example.
- Thus, the mobile station is not always able to receive signals identical in contents from a plurality of base stations corresponding to the ever-stable number of base stations. Namely, the fragments of the code words are not always complete or available. Therefore, the mobile station has to be able to decode desired information even from one received signal from one arbitrary base station, i.e., one arbitrary fragment of each code word.
- The present invention has been completed to solve the foregoing problems. Owing to the setting of encoding in respective base stations to injection, signals each including the same contents, which are received by a mobile station, are used for increasing the reliability of communications without depending on the number of the signals which were capable of being received by the mobile station, thereby reducing transmitting power for satisfying required communication quality. Further, a wireless apparatus according to the present invention comprises a plurality of wireless transmitting stations each provided with a transmitting antenna, a transmitter capable of transmission through a pre-specified radio channel, an encoder for performing encoding processing corresponding to the radio channel, and a data input interface for obtaining data to be transmitted from an external device; and a wireless receiving station including a receiving antenna, a receiver capable of independently receiving signals from a plurality of radio channels, a plurality of buffers for respectively storing received data therein according to the received radio channels, a selector A for reading the data from the plurality of buffers and sending the data to either one of a plurality of decoders and a data combiner according to the read buffers, the data combiner for combining data in predetermined order, a plurality of decoders for respectively executing predetermined decoding processes, a selector B for selecting decoded data in interlock with the selector A and outputting the same therefrom, and a data output interface for supplying the received and decoded data to an external device.
- These and other objects and many of the attendant advantages of the invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings.
- The present invention will be described with reference to the accompanying drawings in which:
- FIG. 1 is a diagram for describing one example of a diversity radio communication apparatus according to the present invention;
- FIG. 2 is a diagram for describing another example of a diversity radio communication apparatus according to the present invention;
- FIG. 3 is a diagram for describing a further example of a diversity radio communication apparatus according to the present invention;
- FIG. 4 is a diagram for describing a still further example of a diversity radio communication apparatus according to the present invention;
- FIG. 5 is a diagram showing one example of an effect of the present invention;
- FIG. 6 is a diagram for describing one condition for calculations upon showing one example of the effect of the present invention; and
- FIG. 7 is a diagram for describing one characteristic in one example of the effect of the present invention.
- An embodiment to which the present invention is applied, will be explained with reference to FIG. 1. In the same drawing,
reference numerals reference numeral 21 indicates a wireless receiving station. Thewireless transmitting stations wireless receiving station 21 correspond to base stations and a mobile station used in mobile communications respectively. In thewireless transmitting station 01, adata input interface 014 controls the input of data between an external data generator and anencoder 013. Theencoder 013 performs encoding oninput data 016 to output acode word 015. An encoding method of theencoder 013 is determined according to aradio channel 11 used by atransmitter 012. The details of the encoding method will be described later. Thetransmitter 012 performs conversion to a radio signal format, modulation, frequency conversion, filter processing and amplification on thecode word 015 and thereafter transmits the processed code word through anantenna 011. - A transmitting process of the
wireless transmitting station 02 is substantially similar to thewireless transmitting station 01. An encoding method of anencoder 023 is determined according to aradio channel 12 used by atransmitter 022. Both transmitting stations are different from each other in theradio channels transmitters encoders radio channels - In the
wireless receiving station 21,reference numeral 212 indicates a receiver and independently receives signals for theradio channels antenna 211. Thereceiver 212 performs amplification, frequency conversion, filter processing, demodulation and conversion from a radio signal format to receiveddata 2190 on the received signals on theradio channels receiver 212 temporarily stores the receiveddata 2190 in abuffer 2131. If the received radio channel is found to be 12, then thereceiver 212 temporarily stores the receiveddata 2190 in abuffer 2132. Next, the data temporarily stored in thebuffers decoding unit 216. How to decode the data here is determined according to receiving conditions at the radio ischannels wireless stations data output interface 218 performs control foroutputting output data 2194 decoded by thedecoding unit 216 to an external data sink. - The operation of the
decoding unit 216 will be explained in detail. Since radio propagation environments in mobile communications change minute by minute, the receiving station is not always able to receive desired data from both theradio channels wireless transmitting stations buffers selector A 2151 checks for the presence or absence of the received data in thebuffers buffer 2131 alone, then theselector A 2151 reads it and inputs the received data to adecoder 2161. On the other hand, when it is found that the data has been stored in thebuffer 2132 alone, theselector A 2151 reads it and inputs the received data to adecoder 2162. - The
decoders encoders encoders wireless transmitting stations wireless transmitting stations buffers selector A 2151 checks for the presence or absence of the received data lying within thebuffers buffers selector A 2151 reads the received data from the two buffers and inputs the same to a data combiner 217. The data combiner 217 integrates and combines the plurality of received data obtained from both thebuffers decoder 2160 decodes the combined data. How to integrate, combine and decode the data here is determined depending on the encoding methods of theencoders wireless transmitting stations - Summaries of the encoding methods of the
encoders wireless transmitting stations data combiner 217 anddecoders wireless receiving station 21 will consecutively be explained. - The encoding methods of the
encoders encoders wireless receiving station 21 does not always receive both signals transmitted from thewireless transmitting stations - The decoding methods employed in the
decoders wireless receiving station 21 will next be described. Thedecoders encoders encoders decoders - The data combining method of the
data combiner 217 will continuously be described. Thewireless transmitting stations radio channels wireless receiving station 21, thewireless receiving station 21 is able to specify either of the fragments thereof according to the received radio channel. When both the fragments of the divided code words are received by thewireless receiving station 21, thedata combiner 217 performs an operation opposite to the dividing procedure defined in advance to thereby re-arrange the received ones in a manner similar to the code words before division generated in thewireless transmitting stations - The decoding method of the
decoder 2160 will next be explained. A decoding process corresponding to the method of encoding the code words before division generated in thewireless transmitting stations decoder 2160. - The details of encoding/decoding will be disclosed herein. An example of an encoding/decoding method constructed based on algebraic-geometric codes is shown as a first embodiment. According to the theory of algebraic-geometric codes introduced by V. D. Goppa (see e.g. Hideki Imai, Coding theory, Japan: IEICE, pp. 182-188, 1990), the following map Φ provides or gives q-ary (n, m−g) linear codes wherein a code length is n and the number of information symbols is (m−g), assuming that F: a finite field GF (q), X: an algebraic curve, Q: an F-rational point on X, P1, P2, . . . , Pn: n distinct, F-rational points on X different from Q, G: a divisor (m−1)Q, where m≦n, D: a divisor P1+P2+ . . . +Pn, L(G): the linear space of rational functions on X associated to G. However, g indicates the genus of the algebraic curve X.
- Since the linear space L (G) is of the same type as a linear space Fm-g, an arbitrary q value data sequence u having a length (m−g) can be associated with an element f of L(G) in a one-to-one relationship without omission.
- In the present invention, m and n, which satisfy l (m−g)≦n with respect to an integer l greater than or equal to a given 2 in the above-described codes, are selected. Further, n′, which satisfies n′≦∥n/l∥ and n′≧(m−g), is selected. However, ∥x∥ is the maximum positive number not exceeding x.
- Now consider where l=2 and a sequence of
input data encoder 013 in thewireless transmitting station 01 effects encoding based on the following map Φ1 on the same data sequence u to thereby obtain a code word c1. - Further, the
encoder 023 in thewireless transmitting station 02 effects encoding based on the following map Φ2 on the same data sequence u to thereby obtain a code word c2. - The above-described maps Φ1 and Φ2 respectively provide q-ary (n′, m−g) linear codes C1 and C2 in which a code length is n′ and the number of information symbols is (m−g). Each of the designed distance about the present codes according to V. D. Goppa, i.e., dC1=dC2=n′−m+1.
- Decoding of the
decoders wireless receiving station 21 is carried out by applying the conventional decoding method (see e.g., T. Høholdt & R. Pellikaan, “On the Decoding of Algebraic Geometry Codes”, IEEE Transactions on Information Theory, Volume 41,Number 6, pp. 1589-1614) of algebraic-geometric codes with respect to the maps Φ1 and Φ2. - The data combiner217 of the
wireless receiving station 21 combines received data sequences r1=(r1 1, r1 2, . . . , r1 n′) to r2=(r2 1, r2 2, . . . , r2 n′) read from thebuffers decoder 2160. In practice, the combined received data sequence (r1r2) results in a sequence obtained by addition of some error sequence on a communication channel to a code word of a q-ary (2n′, m−g) linear code C12 given by map Φ12: L(G)f→(f(P1), f(P2), . . . , f(P2n′))∈F2n′. Since the designed distance dC12 about the present code according to V. D. Goppa becomes dC12=2n′−m+ 1, the linear code C12 has much stronger error correcting capability as compared with the linear codes C1 and C2. In other words, when the data sent from thewireless transmitting stations decoder 2160 is performed by applying the conventional decoding method (see e.g., T. Høholdt & R. Pellikaan, “On the Decoding of Algebraic Geometry Codes”, IEEE Transactions on Information Theory, Volume 41,Number 6, pp. 1589-1614) of algebraic-geometric codes with respect to the map Φ12. - In the first embodiment, the code rate of the linear codes C1 and C2 may be set to 1 with n′=m−g and g=0. Since the maps Φ1 and Φ2 are of isomorphism, the minimum distance for each of the linear codes C1 and C2 becomes 1 and hence no error correcting capability exists. However, the decoding process executed by each of the
decoders - An example of an encoding/decoding method constructed based on convolutional codes will next be explained as a second embodiment. A method of representing convolutional codes is first prepared (see e.g., Hideki Imai, Coding theory, Japan: IEICE, pp. 182-188, 1990). A delimited data sequence is defined as m0m1m2 . . . , and an encoded sequence is defined as w0w1w2 . . . . However, a data block mt and a code block wt (where t=0, 1, 2, . . . ) are respectively sequences over GF (q) having lengths of k and n, and expressed as follows:
- mt=(m1t, m2t, . . . , mkt), wt=(w1t, w2t, . . . , wnt)
- Further, the data sequence and encoded sequence are respectively expressed in the following plynomial representation with D as a delay operator:
- M(D)=m0+m1D+m2D2+ . . .
- W(D)=w0+w1D+w2D2+ . . .
- If Mi(D) and Wj(D) are respectively represented as
- Mi(D)=mi0+mi1D+mi2D2+ . . . , (where i=1, 2, . . . , k) and
- Wj(D)=wj0+wj1D+wj2D2+ . . . , (where j=1, 2, . . . , n)
- then M(D) and W(D) are expressed as follows:
- M(D)=(M1(D), M2(D), . . . , Mk(D))
- W(D)=(W1(D), W2(D), . . . , Wn(D))
-
- An element Gij(D) of G(D) will be described in the following manner as a polynomial for D of the degree v(ij) with elements gij0, gij1, . . . , gij(v(ij)) over GF(q) as coefficients.
- Gij(D) is represented as follows:
- Gij(D)=gij0+gij1D+ . . . +gij(v(ij))Dv(ij)
- where gij(v(ij))≠0.
- In the present invention, k and n, which satisfy lk≦n with respect to an integer l greater than or equal to 2 in the convolutional codes represented in the above-described manner, are selected. Further, n′, which satisfies n′≦∥n/l∥ and n′≧k, is selected. However, ∥x∥ is the maximum positive number not exceeding x.
-
- where c1=w1 0w1 1 . . . w1 N−1, w1 t (t=0, 1, . . . , N−1) indicates a sequence over GF(q) having a length n, and w1 t=(w1 t1, w1 2t, . . . , w1 n′t).
-
- where c2=w2 0w2 1 . . . w2 N−1, w2 t (t=0, 1, . . . , N−1) indicates a sequence over GF(q) having a length n, and w2 t=(w2 (n′+1)t, w2 (n′+2)t, . . . , w2 (2n′)t).
- The transfer function matrixes G1(D) and G2(D) respectively provide convolutional codes C1 and C2 each given at the code rate k/n′.
- The decoding of the
decoders wireless receiving station 21 is performed by applying the conventional decoding method (e.g., the Viterbi decoding algorithms) of convolutional codes with respect to encoding based on the transfer function matrixes G1(D) and G2(D). - The data combiner217 of the
wireless receiving station 21 combines received data sequences r1=r1 0 r1 1 . . . r1 N−1 to r2=r2 0 r2 1 . . . r2 N−1 read from thebuffers - (r1r2)=(r1 0 r2 0 r1 1 r2 1 . . . r1 N−1 r2 N−1)
-
- The transfer function matrix G12(D) provides a convolutional code C12 given at the code rate k/(2n′). Thus the convolutional code C12 includes much stronger error correcting capability as compared with the convolutional codes C1 and C2. In other words, when the data sent from the
wireless transmitting stations decoder 2160 is performed by applying the conventional decoding method (e.g., the Viterbi decoding algorithms) of convolutional codes with respect to the transfer function matrix G12(D). - If convolutional codes are generated over GF(2) with, for example, n′=1 and k=1 and the transfer function matrixes G1(D)=[1+D2+D3+D4+D8] and G2(D)=[1+D+D2+D3+D5+D7+D8] in the second embodiment, then they correspond to encoding by a linear-feedforward shift register and error correcting capability thereof is equal to nothing. However, since the reverse encoding processes by linear-feedforward shift register may be executed as the decoding processes of the
decoders decoders D 8 1+D+D2+D3+D5+D7+D8] and provides binary convolutional codes in which the code rate is ½ and the minimum free distance is 12. In the second embodiment, data about the end mN−V+1mN−V+2 . . . mN−1 of the input data sequence m0m1 . . . mN−1 may be all set to zero as one method of terminating the Viterbi decoding algorithms. Here, V indicates the constraint length of the convolutional code C12. - Applications according to the present invention will next be described. In the foregoing embodiments, if either the
radio channels wireless transmitting stations decoders decoder 2160. As a method of checking the states of reception of theradio channels - One embodiment based on “(1) the method using the received signal strength value” will first be described as the first application according to the present invention with reference to FIG. 2. If the present embodiment shown in the same drawing is compared with FIG. 1 illustrative of one example of the diversity wireless communication apparatus, then the differences reside in a
receiver 212′ of awireless receiving station 21′, buffers 2131′ and 2132′ and aselector A 2151′ in adecoding unit 216′. Thereceiver 212′ outputs even received signal strength value obtained upon their reception at the respective radio channels in connection with the output of data received through the respective radio channels. Thebuffers 2131′ and 2132′ respectively store therein the received signal strength value at their reception at theradio channels selector A 2151′ checks for the presence or absence of received data inbuffers buffer 2131 alone, then theselector A 2151′ reads it and inputs the received data to adecoder 2161. If it is found that the data has been stored in thebuffer 2132 alone in reverse, then theselector A 2151′ reads it and inputs the received data to adecoder 2162. Further, when theselector A 2151′ checks for the presence or absence of the received data in thebuffers buffers selector A 2151′ reads the received signal strength value from thebuffer 2131′ and compares it with a predetermined reference value. If the received signal strength value is found to exceed the reference value from the above comparison, then theselector A 2151′ reads the received data from thebuffer 2131 and inputs it to thedecoder 2161. On the other hand, when the received signal strength value is found not to exceed the reference value, theselector A 2151′ reads the received signal strength value from thebuffer 2132′ and compares it with a predetermined reference value. If the received signal strength value is found to exceed the reference value from the above comparison, then theselector A 2151′ reads the received data from thebuffer 2132 and inputs it to thedecoder 2162. When any of the received signal strength value read from thebuffers 2131′ and 2132′ is found not to exceed the reference value from the result of the comparison, theselector A 2151′ reads the received data from both thebuffers data combiner 217. - Thus, the adoption of the configuration shown in FIG. 2 allows a decision as to the states of the
radio channels radio channels wireless transmitting stations - One embodiment based on “(2) the error detection-based method” will next be described as the second application according to the present invention with reference to FIG. 3. If the present embodiment shown in the same drawing is compared with FIG. 1 illustrative of one example of the diversity wireless communication apparatus according to the present invention, then the differences reside in
encoders 013″ and 023″ of wireless transmitter or transmittingstations 01″ and 02″, aselector A 2151″ in adecoding unit 216′ of awireless receiving station 21″, anddetectors encoders 013″ and 023″ respectively generate only a predetermined code word fragment for an error correcting code from one data sequence as in the case of theencoders encoders 013″ and 023″ respectively output ones obtained by calculating an error detecting check bit and applying it. However, when such an encoding method that the generated arbitrary code word fragment itself has suitable error detecting capability is adopted in the process of generating only the predetermined code word fragment for the error correcting code from one data sequence, the process for calculating the error detecting check bit and applying it may be omitted. It is of importance that the encoding done by theencoders 013″ and 023″ is associated with injection but not with surjection. Thedetectors receiver 21″ respectively check for the presence or absence of received data stored inbuffers buffers detectors encoders 013″ and 023″ and output the presence or absence of error detection to theselector A 2151″. Theselector A 2151″ checks for the presence or absence of received data in thebuffers buffer 2131 alone, then theselector A 2151″ reads it and inputs the received data to adecoder 2161. If the data is found to have been stored in thebuffer 2132 alone in reverse, then theselector A 2151″ reads it and inputs the received data to adecoder 2162. When theselector A 2151″ checks for the presence or absence of the received data in thebuffers buffers selector A 2151″ refers to the result of error detection from thedetector 2141. If the error detection is found to be nil, then theselector A 2151″ reads the received data from thebuffer 2131 and inputs it to thedecoder 2161. On the other hand, when the error detection is found to have been made, theselector A 2151″ next refers to the result of error detection from thedetector 2142. If the error detection is found to be nil, then theselector A 2151″ reads the received data from thebuffer 2132 and inputs it to thedecoder 2162. If it is found that an error has been detected from both of thedetectors selector A 2151″ reads the received data from both thebuffers data combiner 217. - Thus, the adoption of the configuration shown in FIG. 3 allows a decision as to the states of the
radio channels radio channels wireless transmitting stations - While all the above-described embodiments have shown the case in which the two wireless transmitting stations respectively transmit the data to the wireless receiving station through one radio channel, the number of the wireless transmitting stations is not limited to two in the present invention. An embodiment in which three wireless transmitting stations respectively transmit data to their corresponding wireless receiving station through one radio channel, is shown in FIG. 4 as the third application according to the present invention. In the same drawing,
reference numerals 01 through 03 indicate wireless transmitting stations respectively, andreference numeral 21″′ indicates a wireless receiving station. - In the
wireless transmitting station 01, thedata input interface 014 controls the input of data between an external data generator and theencoder 013. Theencoder 013 performs encoding on theinput data 016 to output acode word 015. An encoding method of theencoder 013 is determined according to theradio channel 11 used by thetransmitter 012 but the details thereof will be described later. Thetransmitter 012 performs conversion to a radio signal format, modulation, frequency conversion, filter processing and amplification on thecode word 015 and thereafter transmits the processed code word through theantenna 011. In thewireless transmitting station 02, adata input interface 024 controls the input of data between an external data generator and theencoder 023. Theencoder 023 performs encoding oninput data 026 to output acode word 025. An encoding method of theencoder 023 is determined according to theradio channel 12 used by thetransmitter 022 but the details thereof will be described later. Thetransmitter 022 performs conversion to a radio signal format, modulation, frequency conversion, filter processing and amplification on thecode word 025 and thereafter transmits the processed code word through anantenna 021. In awireless transmitting station 03, adata input interface 034 controls the input of data between an external data generator and anencoder 033. Theencoder 033 performs encoding oninput data 036 to output acode word 035. An encoding method of theencoder 033 is determined according to aradio channel 13 used by atransmitter 032 but the details thereof will be described later. Thetransmitter 032 performs conversion to a radio signal format, modulation, frequency conversion, filter processing and amplification on thecode word 035 and thereafter transmits the processed code word through an antenna 031. Thewireless transmitting stations 01 through 03 are different from one another in theradio channels 11 through 13 used by their correspondingtransmitters corresponding encoders radio channels 11 through 13 are not necessarily limited to hose specified by frequencies and also include those specified by time slots or spread spectrum codes. - In the
wireless receiving station 21″′,reference numeral 212 indicates a receiver and has the function of independently receiving signals for theradio channels 11 through 13 through theantenna 211. Thereceiver 212 performs amplification, frequency conversion, filter processing, demodulation and conversion from a radio signal format to receiveddata 2190 on the received signals on theradio channels 11 through 13. If the received radio channel is found to be 11, then thereceiver 212 temporarily stores the receiveddata 2190 in thebuffer 2131. If the received radio channel is found to be 12, then thereceiver 212 temporarily stores the receiveddata 2190 in thebuffer 2132. If the received radio channel is found to be 13, then thereceiver 212 temporarily stores the receiveddata 2190 in abuffer 2133. Next, the received data temporarily stored in thebuffers 2131 through 2133 are read and decoded by adecoding unit 216″′. How to decode the data here is determined according to receiving conditions at theradio channels 11 through 13 and the encoding methods of thewireless stations 01 through 03 but the details thereof will be described later. Thedata output interface 218 performs control for outputting output data decoded by thedecoding unit 216″′ to an external data sink. - The operation of the
decoding unit 216″′ will next be explained in detail. Since radio propagation environments in mobile communications change moment by moment, the receiving station is not always able to receive desired data from all theradio channels 11 through 13. When the data sent from thewireless transmitting stations 01 through 03 are received only from either one of the radio channels, the received data is stored in either one of thebuffers 2131 through 2133 according to the radio channel having received the corresponding data therethrough. Aselector A 2151 checks for the presence or absence of the received data in thebuffers 2131 through 2133. If it is found that the data has been stored in thebuffer 2131 alone, then theselector A 2151 reads it and inputs the received data to thedecoder 2161. On the other hand, when it is found that the data has been stored in thebuffer 2132 alone, theselector A 2151 reads it and inputs the received data to thedecoder 2162. Alternatively, if it is found that the data has been stored in thebuffer 2133 alone, then theselector A 2151 reads it and inputs the received data to adecoder 2163. Thedecoders 2161 through 2163 are respectively decoders corresponding to the encoding methods of theencoders wiring stations 01 through 03 but the details thereof will be explained later. When the data from thewireless transmitting stations 01 through 03 are received from a plurality of radio channels, the received data are respectively stored in thebuffers 2131 through 2133 corresponding to the radio channels having received the corresponding data. Theselector A 2151 checks for the presence or absence of the received data lying within thebuffers 2131 through 2133 and detects the storage of the data in the plurality ofbuffers 2131 through 2133. Further, theselector A 2151 reads the received data from the plurality of buffers respectively and inputs the same to thedata combiner 217″′. Thedata combiner 217″′ integrates and combines the plurality of received data obtained from thebuffers 2131 through 2133 and outputs combined receiveddata 2192 andintegrated information 2193 indicative of which received data is integrated. Adecoder 2160″′ decodes the combined receiveddata 2192, based on theintegrated information 2193 from thedata combiner 217″′. How to integrate, combine and decode the data here is determined depending on the encoding methods employed in thewiring stations 01 through 03 and a decision as to which radio channel have receives data, but the details thereof will be described later. - Summaries of the encoding methods of the
encoders wireless transmitting stations 01 through 03 and the data combining/decoding methods of thedata combiner 217″′ anddecoders 2161 through 2163 and 2160″′ in thewireless receiving station 21 will consecutively be explained. Examples of actual encoding/decoding methods will be described later. The encoding methods of theencoders encoders encoders wireless transmitting stations 01 through 03, a limitation is imposed on the encoding method so that the data sequence can be decoded even from one fragment alone. Described specifically, mapping from the data sequence to the fragment of the code word is limited to injection. The decoding methods employed in thedecoders 2161 through 2163 will next be described. Thedecoders 2161 through 2163 respectively perform decoding processes corresponding to the encoding methods of theencoders encoders decoders 2161 through 2163 result in matrix multiplication. The data combining method of thedata combiner 217 will continuously be described. Thewireless transmitting stations 01 through 03 respectively generate a code word in an error correcting code from one input data sequence and divide the code word into three. Further, they respectively transmit respective fragments of the divided code words through theradio channels 11 through 13 different from each other therefrom. Therefore, when the fragments of the divided code words are received by thewireless receiving station 21″′, thewireless receiving station 21″′ is able to specify either of the fragments thereof according to the received radio channel. When the three fragments of the divided code words are all received by thewireless receiving station 21″′, thedata combiner 217″′ performs an operation opposite to the dividing procedure defined in advance to thereby re-arrange sort the received ones in a manner similar to the code words before division generated in thewireless transmitting stations 01 through 03. When thewireless receiving station 21″′ receives two of the fragments of the divided code words, the two received data are re-arranged by a predetermined procedure according to the received data. A decoding method of the 2160″′ will be explained. When all the fragments of the code words are available, thedecoder 2160″′ performs a decoding process corresponding to the method of encoding the code words before division generated in thewireless transmitting stations 01 through 03. When the two of the fragments of the code words are available, thedecoder 2160″′ performs a decoding process corresponding to an encoding method obtained by modifying the method of encoding each pre-division code word before division. Here, the encoding method obtained by modifying the method of encoding each code word before division is equivalent specifically to puncturing of the code. Since such puncturing of the code shows the case in which the two of the three fragments of the code words are available, three possible processes, i.e., 3C2=3 exist. Thus, three possible decoding processes to be executed by thedecoder 2160″′ at the time that the two of the fragments of the code words are available, exist. Further, the number of the decoding processes exists four as a whole when the decoding process at the time that all the fragments of the code words are available, is included. Which decoding process should be effected on the combined receiveddata 2192 by thedecoder 2160″′, is based on theintegrated information 2193 of thedata combiner 217″′. - An example of the actual encoding/decoding method will be explained. In the first embodiment, for example, l=3 and the
encoder 013 of thewireless transmitting station 01 effects encoding based on the following map Φ1 on an input data sequence u to thereby obtain a code word c1. - Further, the
encoder 023 of thewireless transmitting station 02 effects encoding based on the following map Φ2 on the same data sequence u to thereby obtain a code word c2. - Furthermore, the
encoder 033 of thewireless transmitting station 03 effects encoding based on the following map Φ3 on the same data sequence u to thereby obtain a code word c3. - The above-described maps Φ1 through Φ3 respectively provide q-ary (n′, m−g) linear codes C1 through C3 in which a code length is given as n′ and the number of information symbols is given as (m−g). Each of the designed distance about the present codes according to V. D. Goppa, i.e., dC1=dC2=dC3=n′−m+1.
- Decoding of the
decoders 2161 through 2163 in thewireless receiving station 21″′ is carried out by applying the conventional decoding method (see e.g., T. Høholdt & R. Pellikaan, “On the Decoding of Algebraic Geometry Codes”, IEEE Transactions on Information Theory, Volume 41,Number 6, pp. 1589-1614) of algebraic-geometric codes with respect to the maps Φ1 through Φ3. - The data combiner217″′ of the
wireless receiving station 21″′ combines received data sequences r1=(r1 1, r1 2, . . . , r1 n′), r2(r2 1, r2 2, . . . , r2 n′), and r3=(r3 1, r3 2, . . . , r3 n′) read from thebuffers 2131 through 2133 into one. As to how to combine them, however, the following four of (1) through (4) exist according to the conditions of reception. - (1) when r1, r2 and r3 are available:
- A sequence (r1r2r3)=(r1 1, r1 2, . . . , r1 n′, r2 1, r2 2, . . . , r2 n′, r3 1, r3 2, . . . , r3 n′) is generated and inputted to the
decoder 2160″′. - (2) when r1 and r2 are available:
- A sequence (r1r2)=(r1 1, r1 2, . . . . , r1 n′, r2 1, r2 2, . . . , r2 n′) is generated and inputted to the
decoder 2160″′. - (3) when r2 and r3 are available:
- A sequence (r2r3)=(r2 1, r2 2, . . . , r2 n′, r3 1, r3 2, . . . , r3 n′) is generated and inputted to the
decoder 2160″′. - (4) when r1 and r3 are available:
- A sequence (r1r3)=(r1 1, r1 2, . . . , r1 n′, r3 1, r3 2, . . . , r3 n′) is generated and inputted to the
decoder 2160″′. - The sequence (r1r2r3) results in a sequence obtained by addition of some error sequence on each communication channel to a code word of a q-ary (3n′, m−g) linear code C123 given by the following map.
- The sequence (r1r2) results in a sequence obtained by addition of some error sequence on each communication channel to a code word of a q-ary (2n′, m−g) linear code C12 given by the following map.
- The sequence (r2r3) results in a sequence obtained by addition of some error sequence on each communication channel to a code word of a q-ary (2n′, m−g) linear code C23 given by the following map.
- The sequence (r1r3) results in a sequence obtained by addition of some error sequence on each communication channel to a code word of a q-ary (2n′, m−g) linear code C13 given by the following map.
- Since designed distances about the linear codes C12, C23 and C13 according to V. D. Goppa become dC12=dC23=dC13=2n′−
m+ 1, the linear codes C12, C23 and C13 include much stronger error correcting capability as compared with the linear codes C1 through C3. In other words, when the data sent from thewireless transmitting stations 01 through 03 are received from the two radio channels, the data can be decoded as a code word provided with much stronger error correcting capability as compared with when received only from either one of the transmitting stations. Further, since the designed distance of the linear code C123 according to V. D. Goppa becomes dC123=3n′−m+ 1, the linear code C123 includes much stronger error correcting capability as compared with the linear codes C12, C23 and C13. In other words, when the data sent from thewireless transmitting stations 01 through 03 are received from all the radio channels, the data can be decoded as a code word provided with much stronger error correcting capability as compared with when received only from the two transmitting stations at the most. Now, the linear codes C12, C23 and C13 correspond to punctured codes obtained by puncturing a parity check part by an n′ symbol from the linear code C123. Incidentally, the decoding of thedecoder 2160″′ is performed by applying the conventional decoding method (see e.g., T. Høholdt & R. Pellikaan, “On the Decoding of Algebraic Geometry Codes”, IEEE Transactions on Information Theory, Volume 41,Number 6, pp. 1589-1614) of algebraic-geometric codes with respect to the respective maps Φ12, Φ23, Φ13 and Φ123. - An example of another encoding/decoding method will next be explained. In the second embodiment, l=3, for example. Further, the
encoder 013 of thewireless transmitting station 01 effects encoding based on the following transfer function matrix G1(D) on an input data sequence m0m1 . . . mN−1 to thereby obtain a code word c1. - where c1=w1 0 w1 1 . . . w1 N−1, and w1 t (t=0, 1, . . . , N−1) indicates a sequence over GF(q) having a length, i.e., w1 t=(w1 1t, w1 2t, . . . , w1 n′t).
-
- where c2=w2 0w2 1 . . . w2 N−1, and w2 t (t=0, 1, . . . , N−1) indicates a sequence over GF(q) having a length n, i.e., w2 t=(w2 (n′+1)t, w2 (n′+2)t, . . . , w2 (2n′)t).
-
- where c3=w3 0w3 1 . . . w3 N−1, and w3 t (t=0, 1, . . . , N−1) indicates a sequence over GF(q) having a length n, i.e. w3 t=(w3 (2n′+1)t, w3 (2n′+2)t, . . . , w3 (3n′)t).
- The transfer function matrixes G1(D) through G3(D) respectively provide convolutional codes C1 through C3 each given at an code rate k/n′.
- The decoding of the
decoders 2161 through 2163 of thewireless receiving station 21″′ is performed by applying the conventional decoding method (e.g., the Viterbi decoding algorithms) of convolutional codes with respect to encoding based on the transfer function matrixes G1(D) through G3(D). - The data combiner217″′ of the
wireless receiving station 21″′ combines received data sequences r1=r1 0, r1 1 . . . r1 N−1, r2=r2 0 r2 1 . . . r2 N−1, and r3=r3 0 r3 1 . . . r3 N−1 read from thebuffers 2131 through 2133 into one. As to how to combine them, however, the following four of (1) through (4) exist according to the conditions of reception. - (1) when r1, r2 and r3 are available:
- A sequence (r1r2r3)=(r1 0 r2 0 r3 0 r1 1 r2 1 r3 1 . . . r1 N−1 r2 N−1 r3 N−1) is generated and inputted to the
decoder 2160″′. - (2) when r1 and r2 are available:
- A sequence (r1r2)=(r1 0 r2 0 r1 1 r2 1 . . . r1 N−1 r2 N−1) is generated and inputted to the
decoder 2160″′. - (3) when r2 and r3 are available:
- A sequence (r2r3)=(r2 0 r3 0 r2 1 r3 1 . . . r2 N−1 r3 N−1) is generated and inputted to the
decoder 2160″′. - (4) when r1 and r3 are available:
- A sequence (r1r3)=(r1 0 r3 0 r1 1 r3 1 . . . r1 N−1 r3 N−1) is generated and inputted to the
decoder 2160″′. -
-
-
-
- The transfer function matrixes G12(D), G23(D) and G13(D) respectively provide convolutional codes C12, C23 and C13 each given at an code rate k/(2n′). Thus the convolutional codes C12, C23 and C13 respectively include much stronger error correcting capability as compared with the convolutional codes C1 through C3. In other words, when the data sent from the
wireless transmitting stations 01 through 03 are received from the two radio channels, the data can be decoded as a code word provided with much stronger error correcting capability as compared with when received only from either one of the transmitting stations. Further, the transfer function matrix G123(D) provides a convolutional code C123 given at a code rate k/(3n′). Thus, the convolution code C123 provides much stronger error correcting capability as compared with the convolutional codes C1 through C3 and C12, C23 and C13. In other words, when the data sent from thewireless transmitting stations 01 through 03 are received from all the radio channels, the data can be decoded as a code word provided with much stronger error correcting capability as compared with when received only from the two transmitting stations at most. - Incidentally, the decoding of the
decoder 2160″′ is performed by applying the conventional decoding method (e.g., the Viterbi decoding algorithms) of convolutional codes with respect to respective encoding based on the transfer function matrixes G12(D), G23(D), G13(D) and G123(D). - While the third application according to the present invention has shown the case in which the three wireless transmitting stations respectively transmit the data to the wireless receiving station through one radio channel, application to the case in which m wireless transmitting stations normally respectively transmit data to a wireless receiving station through one radio channel, is easy. A summary thereof in this case will be described. First, m radio channels are set, and m wireless transmitting stations respectively generate a code word in the same error correcting code from one input data sequence and divide it into m. Further, the m wireless transmitting stations respectively transmit one of predetermined m fragments to a wireless receiving station through one of predetermined m radio channels. The wireless receiving station is provided with m buffers corresponding to the respective radio channels. Decoding is performed by decoders having decoding processing methods corresponding to the number of combinations of the resultant code word fragments, according to the conditions of reception. If l=m in the first and second embodiments, it is then easily imagined that such an encoding/decoding method would be obtained as an actual encoding/decoding method. Incidentally, the first and second applications according to the present invention can be easily applied even to the third application according to the present invention or the case in which the general m wireless transmitting stations exist.
- FIG. 5 shows one example of an effect of the present invention, which corresponds to the results obtained by supposing the following conditions (1) through (3) and calculating bit error rates of received data of the
wireless receiving station 21 to transmitting power of thewireless transmitting stations - (1) Condition for the positions of wireless stations: The
wireless transmitting stations wireless receiving station 21 through their correspondingradio communication channels wireless receiving station 21 receives data from thewireless transmitting stations wireless transmitting station 01 and thewireless transmitting station 02 as both ends between a point X1 spaced 100 m away from thewireless transmitting station 01 and a point X2 spaced 1100 m away therefrom (see FIG. 6). Here, the existing positions of thewireless receiving station 21 over the line segments X1 and X2 will be placed under uniform distribution. - (2) Condition for propagation environments: The condition is placed under a stationary flat fading environment. Receiving power will be attenuated in proportion to the square of the distance from each transmitting station to the point spaced 100 m away therefrom and attenuated in proportion to the fourth power of the distance at above it.
- (3) Condition for radio communication system: A radio frequency is set to a 2.4 GHz band and a bandwidth is set to 26 MHz. In the
transmitters wireless transmitting stations receiver 212 of thewireless receiving station 21, a demodulation system will be defined as differential detection, and diversity for pure-selection combining two diversity channels will be applied after the detection. Further, the noise factor of the receiver and the temperature thereof are regarded as 7 dB and 300K respectively. Incidentally, the gains of the transmittingantennas antenna 211 will be defined as 2.14 dBi respectively. - Referring to FIG. 5, “the conventional system” is a system for selecting either one of data of 600 bits respectively received from the
radio communication channels - A “
system 1 according to the present invention” is one example in which the first embodiment according to the present invention is applied. Described specifically, the genus g=0 and F=GF(28). Further, theencoders decoding unit 216 performs an error check on the received data sent from thewireless transmitting stations decoder 2160 performs a bounded distance decoding process on the minimum distance 76. Incidentally, the probability of undetected error at the error check is supposed to be 0 for simplicity. - A “
system 2 according to the present invention” is one example in which the second embodiment according to the present invention is applied. Described specifically, theencoders D 8 1+D+D2+D3+D5+D7+D8]. A convolutional code C12 provides the code rate of ½ and a minimum free distance of 12. Thedecoding unit 216 performs an error check on the received data sent from thewireless transmitting stations stations decoder 2160 performs a process for the Viterbi decoding algorithms. Incidentally, the probability of undetected error at the error check is supposed to be 0 for simplicity. In the “system 2 according to the present invention” 8 bits corresponding to the final input at encoding is regarded as 0 as one technique of terminating the Viterbi decoding algorithms. - According to FIG. 5, it is understood that when the bit error rate is 10−6, for example, the “
system 1 according to the present invention” and “system 2 according to the present invention” can respectively reduce transmitting power by 3 to 4 dB as compared with the “conventional system”. - On the other hand, FIG. 7 shows a result obtained when the position of the
wireless receiving station 21 is limited to a middle point between thewireless transmitting stations system 1 according to the present invention” and “system 2 according to the present invention” respectively bring about an advantageous effect in that when the bit error rate is 10−6, for example, transmitting power can be reduced by 6.5 to 8 dB as compared with the “conventional system”. - Thus, in the diversity wireless transmitting/receiving system for transmitting data having the same contents from a plurality of wireless transmitting stations and performing diversity reception of the data having the same contents, when the respective transmitting stations respectively perform encoding on the data having the same contents in advance according to respective radio channels through which the respective transmitting stations transmit the data, the respective encoding are carried out so that one of fragments of code words in error correcting codes is generated and fragments of code words corresponding to the plurality of radio channels form one code word in an error correcting code. Further, the respective maps are set to injection. On the other hand, the wireless receiving station stores the received data therein according to the received radio channel and applies decoding processes different according to the number of the received data. When data can be received only from the nearest wireless transmitting station due to reasons such as the existence of the wireless receiving station in the neighborhood of one wireless transmitting station, such received data normally has a high degree of reliability. Therefore, desired data can be obtained by decoding the data sent from the nearest wireless transmitting station. Even when data can be received from a plurality of wireless transmitting stations due to reasons such as the existence of a wireless receiving station in a point located midway between the plurality of wireless transmitting stations, these received data having suitable reliability can be decoded as strong error correcting codes if they are utilized in combination according to a predetermined procedure. Therefore, if compared with such a conventional system as to select one from the received data obtained in plural form, then the possibility that desired data will be obtained, is brought to a leap in improvement. As a result, transmitting power of each wireless transmitting station for satisfying required communication quality can be reduced.
- It is further understood by those skilled in the art that the foregoing description is a preferred embodiment of the disclosed device and that various changes and modifications may be made in the invention without departing from the spirit and scope thereof.
Claims (10)
1. A diversity wireless communication method for transmitting data having the same contents from a plurality of wireless transmitting stations through radio channels different from each other and performing diversity reception of the data having the same contents in a wireless receiving station, comprising the steps of:
allowing said each of the plurality of wireless transmitting stations to effect encoding to be injective and specified by a transmitting radio channel on the data having the same contents;
causing each of the plurality of wireless transmitting stations to transmit encoded data to the wireless receiving station;
allowing the wireless receiving station to temporarily store the received data obtained through the radio channels every radio channel;
when a single received data to be temporarily stored is obtained through a radio channel alone, causing the wireless receiving station to decode the single received data by a decoding method corresponding to encoding specified by a radio channel through which the single received data passed;
when plural received data to be temporarily stored are obtained through plural radio channels, allowing said wireless receiving station to decode the plural received data as a sequence in which an error patter is added to a code word in a error correcting code, after the plural received data are combined in predetermined order according to the radio channels.
2. A diversity wireless communication method according to claim 1 , wherein individual encoding to be specified by each radio channel is encoding based on algebraic-geometric codes, and a divisor used for generation of the code word upon the encoding based on the algebraic-geometric codes is different from one another every radio channel.
3. A diversity wireless communication method according to claim 2 , wherein a genus of an algebraic curve for defining the generation of the code word upon the individual encoding based on the algebraic-geometric codes is assumed to be zero.
4. A diversity wireless communication method according to claim 1 , wherein individual encoding to be specified by each radio channel is encoding based on convolutional codes, and a transfer function matrix used for the generation of the code word upon the individual encoding based on the convolutional codes is different from one another every radio channel.
5. A diversity wireless communication method according to claim 4 , wherein individual encoding to be specified by each radio channel is encoding by linear-feedforward shift register, and the encoding by linear-feedforward shift register is different from one another every radio channel, and the wireless receiving station temporarily stores therein each of the received data obtained from the plurality of wireless transmitting stations respectively, combines the received data in predetermined order according to the radio channels for receiving the received data temporarily stored therein, and thereafter performs an error correction on combined data according to the Viterbi decoding algorithms.
6. A diversity wireless communication method according to claim 1 , wherein the wireless receiving station temporarily stores therein each of the received data obtained through the radio channels and received signal strength value thereof every radio channel, and selects, particularly when some of the received signal strength value of the received data temporarily stored therein exceeds a predetermined threshold, one received data corresponding to the received signal strength value having exceeded the predetermined threshold, and decodes the one received data by a decoding method corresponding to encoding to be specified by a radio channel through which the one received data has passed.
7. A diversity wireless communication method according to claims 1, wherein individual encoding to be specified by each radio channel is not surjection but injection, a method of performing the individual encoding to be specified by each radio channel is known to the wireless receiving station, and the wireless receiving station temporarily stores therein each of the received data obtained through the radio channels every radio channel, and thereafter calculates a syndrome for each of received data, and particularly when some of the received data free of error detection exist, the wireless receiving station selects one received data from some of the received data and decodes the same by a decoding method corresponding to encoding to be specified by a radio channel through which the one received data has passed.
8. A wireless communication apparatus comprising:
a plurality of wireless transmitting stations each provided with a transmitting antenna, a transmitter capable of transmission through a radio channel which is pre-specified, an encoder for performing encoding processing corresponding to the radio channel, and a data input interface for obtaining data to be transmitted from an external device; and
a wireless receiving station including:
a receiving antenna;
a receiver capable of independently receiving signals from a plurality of radio channels;
a plurality of buffers for storing received data respectively therein according to the plurality of radio channels for receiving the received data;
a selector A for reading the received data from the plurality of buffers and sending the received data to either one of a plurality of decoders and a data combiner according to the buffers subjected to the reading;
the data combiner for combining the received data in predetermined order;
the plurality of decoders for respectively executing predetermined decoding processes;
a selector B for selecting decoded data in interlock with the selector A and outputting the same therefrom; and
a data output interface for supplying the received and decoded data to an external device.
9. A wireless communication apparatus according to claim 8 , further comprising a wireless receiving station provided with a receiver for outputting received signal strength value obtained upon reception of the received data, a plurality of buffers for storing the received signal strength value respectively, and a selector A having a function of reading the received signal strength value from the plurality of buffers, comparing the same with a predetermined threshold, selecting one received data corresponding to the received signal strength value exceeding the predetermined threshold, and sending the one received data to a predetermined decoder.
10. A wireless communication apparatus according to claim 8 , further comprising a wireless receiving station provided with a plurality of detectors for respectively reading the received data from the plurality of buffers and performing syndrome calculation corresponding to the buffers subjected to the reading, and a selector A having a function of selecting one received data which brings a result of the syndrome calculation to zero and sending the one received data to a predetermined decoder.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US09/930,977 US6456830B2 (en) | 1999-03-02 | 2001-08-17 | Diversity wireless communication method and its wireless communication apparatus |
Applications Claiming Priority (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP11-053612 | 1999-03-02 | ||
JP05361299A JP3562368B2 (en) | 1999-03-02 | 1999-03-02 | Diversity wireless communication method and wireless communication device thereof |
US09/513,928 US6249669B1 (en) | 1998-06-11 | 2000-02-28 | Diversity wireless communication method and its wireless communication apparatus |
US09/739,396 US6308054B2 (en) | 1999-03-02 | 2000-12-19 | Diversity wireless communication method and its wireless communication apparatus |
US09/930,977 US6456830B2 (en) | 1999-03-02 | 2001-08-17 | Diversity wireless communication method and its wireless communication apparatus |
Related Parent Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US09/739,396 Continuation US6308054B2 (en) | 1999-03-02 | 2000-12-19 | Diversity wireless communication method and its wireless communication apparatus |
Publications (2)
Publication Number | Publication Date |
---|---|
US20020016156A1 true US20020016156A1 (en) | 2002-02-07 |
US6456830B2 US6456830B2 (en) | 2002-09-24 |
Family
ID=26394326
Family Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US09/739,396 Expired - Fee Related US6308054B2 (en) | 1999-03-02 | 2000-12-19 | Diversity wireless communication method and its wireless communication apparatus |
US09/930,977 Expired - Fee Related US6456830B2 (en) | 1999-03-02 | 2001-08-17 | Diversity wireless communication method and its wireless communication apparatus |
Family Applications Before (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US09/739,396 Expired - Fee Related US6308054B2 (en) | 1999-03-02 | 2000-12-19 | Diversity wireless communication method and its wireless communication apparatus |
Country Status (1)
Country | Link |
---|---|
US (2) | US6308054B2 (en) |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2845220A1 (en) * | 2002-09-30 | 2004-04-02 | Canon Kk | Method and device for decoding the algebraic-geometric codes at a point, comprises the construction of a sequence of syndromes matrices ending with a zero row elements matrix |
FR2851096A1 (en) * | 2003-02-10 | 2004-08-13 | Canon Kk | METHOD AND DEVICE FOR ENCODING |
US20050064920A1 (en) * | 2003-09-22 | 2005-03-24 | Tarang Luthra | Reducing interference in high speed home network using signal processing |
US20210351796A1 (en) * | 2019-03-15 | 2021-11-11 | Mitsubishi Electric Corporation | Decoding device, decoding method, control circuit, and storage medium |
Families Citing this family (18)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6507568B2 (en) * | 1997-08-27 | 2003-01-14 | Lucent Technologies Inc. | Enhanced access in wireless communication systems under rapidly fluctuating fading conditions |
JPH11163807A (en) * | 1997-09-29 | 1999-06-18 | Matsushita Electric Ind Co Ltd | Communication system, transmitter and receiver |
US6937592B1 (en) | 2000-09-01 | 2005-08-30 | Intel Corporation | Wireless communications system that supports multiple modes of operation |
US7342875B2 (en) * | 2000-11-06 | 2008-03-11 | The Directv Group, Inc. | Space-time coded OFDM system for MMDS applications |
US6567387B1 (en) | 2000-11-07 | 2003-05-20 | Intel Corporation | System and method for data transmission from multiple wireless base transceiver stations to a subscriber unit |
US20020136287A1 (en) * | 2001-03-20 | 2002-09-26 | Heath Robert W. | Method, system and apparatus for displaying the quality of data transmissions in a wireless communication system |
US7149254B2 (en) * | 2001-09-06 | 2006-12-12 | Intel Corporation | Transmit signal preprocessing based on transmit antennae correlations for multiple antennae systems |
US20030066004A1 (en) * | 2001-09-28 | 2003-04-03 | Rudrapatna Ashok N. | Harq techniques for multiple antenna systems |
US20030067890A1 (en) * | 2001-10-10 | 2003-04-10 | Sandesh Goel | System and method for providing automatic re-transmission of wirelessly transmitted information |
US7336719B2 (en) | 2001-11-28 | 2008-02-26 | Intel Corporation | System and method for transmit diversity base upon transmission channel delay spread |
KR100520621B1 (en) * | 2002-01-16 | 2005-10-10 | 삼성전자주식회사 | Method and apparatus for weighted non-binary repeatative accumulating codes and space-time coding thereof |
US7012978B2 (en) * | 2002-03-26 | 2006-03-14 | Intel Corporation | Robust multiple chain receiver |
US6996373B2 (en) * | 2002-06-18 | 2006-02-07 | Nokia Corporation | Base station |
EP1566899B1 (en) * | 2004-02-23 | 2016-05-11 | Harman Becker Automotive Systems GmbH | Multipath compensation for diversity signal receivers |
US8290492B2 (en) * | 2005-02-08 | 2012-10-16 | Texas Instruments Incorporated | Handover for DVB-H |
JP4609231B2 (en) * | 2005-08-05 | 2011-01-12 | 株式会社日立製作所 | Wireless position detection method and system |
EP1830506A1 (en) * | 2006-03-02 | 2007-09-05 | Dibcom | Method for receiving a signal transmitted over several channels and corresponding device |
DE102017103475A1 (en) * | 2016-02-25 | 2017-08-31 | Toyota Jidosha Kabushiki Kaisha | unit |
Family Cites Families (23)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5157672A (en) * | 1989-03-15 | 1992-10-20 | Nec Corporation | Interference detection apparatus for use in digital mobile communications system |
US5390342A (en) * | 1990-03-14 | 1995-02-14 | Pioneer Electronic Corporation | Receiver using selective diversity receiving system |
US5742896A (en) * | 1990-11-09 | 1998-04-21 | Bose Corporation | Diversity reception with selector switching at superaudible rate |
EP0524184B1 (en) * | 1991-02-08 | 1997-05-02 | Koninklijke Philips Electronics N.V. | Antenna diversity receiving system for eliminating reception interference in mobile television signal reception |
JP2825033B2 (en) | 1991-09-25 | 1998-11-18 | 日本電気株式会社 | Train wireless communication system |
GB2262863B (en) * | 1991-12-23 | 1995-06-21 | Motorola Ltd | Radio communications apparatus with diversity |
US5396645A (en) * | 1992-04-09 | 1995-03-07 | Comcast Pcs Communications, Inc. | System and method for determining whether to assign a macrocell or microcell communication frequency to a mobile communication terminal |
EP0613260B1 (en) * | 1993-02-26 | 2004-09-22 | Kabushiki Kaisha Toshiba | Space diversity receiver for a digital communications system |
CA2116736C (en) * | 1993-03-05 | 1999-08-10 | Edward M. Roney, Iv | Decoder selection |
US5383219A (en) * | 1993-11-22 | 1995-01-17 | Qualcomm Incorporated | Fast forward link power control in a code division multiple access system |
US5541963A (en) * | 1993-12-01 | 1996-07-30 | Hitachi, Ltd. | Diversity receiving apparatus |
MY113061A (en) * | 1994-05-16 | 2001-11-30 | Sanyo Electric Co | Diversity reception device |
JP2669393B2 (en) * | 1995-04-11 | 1997-10-27 | 日本電気株式会社 | Interference wave canceller |
US5757767A (en) * | 1995-04-18 | 1998-05-26 | Qualcomm Incorporated | Method and apparatus for joint transmission of multiple data signals in spread spectrum communication systems |
US5671221A (en) * | 1995-06-14 | 1997-09-23 | Sharp Microelectronics Technology, Inc. | Receiving method and apparatus for use in a spread-spectrum communication system |
US5687197A (en) * | 1995-07-07 | 1997-11-11 | Motorola, Inc. | Method and apparatus for detecting data symbols in a diversity communication system |
JPH09116475A (en) * | 1995-10-23 | 1997-05-02 | Nec Corp | Time diversity transmission/reception system |
US5737365A (en) * | 1995-10-26 | 1998-04-07 | Motorola, Inc. | Method and apparatus for determining a received signal quality estimate of a trellis code modulated signal |
US5893035A (en) * | 1996-09-16 | 1999-04-06 | Qualcomm Incorporated | Centralized forward link power control |
US5710995A (en) * | 1997-01-16 | 1998-01-20 | Ford Motor Company | Adaptive antenna receiver |
JP3451178B2 (en) * | 1997-05-19 | 2003-09-29 | 富士通株式会社 | Space diversity receiver |
US6215777B1 (en) * | 1997-09-15 | 2001-04-10 | Qualcomm Inc. | Method and apparatus for transmitting and receiving data multiplexed onto multiple code channels, frequencies and base stations |
JP2000036801A (en) * | 1998-07-21 | 2000-02-02 | Nec Corp | Diversity receiver |
-
2000
- 2000-12-19 US US09/739,396 patent/US6308054B2/en not_active Expired - Fee Related
-
2001
- 2001-08-17 US US09/930,977 patent/US6456830B2/en not_active Expired - Fee Related
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2845220A1 (en) * | 2002-09-30 | 2004-04-02 | Canon Kk | Method and device for decoding the algebraic-geometric codes at a point, comprises the construction of a sequence of syndromes matrices ending with a zero row elements matrix |
US20040117719A1 (en) * | 2002-09-30 | 2004-06-17 | Canon Kabushiki Kaisha | Methods and devices for decoding one-point algebraic geometric codes |
FR2851096A1 (en) * | 2003-02-10 | 2004-08-13 | Canon Kk | METHOD AND DEVICE FOR ENCODING |
WO2004070956A1 (en) * | 2003-02-10 | 2004-08-19 | Canon Kabushiki Kaisha | Coding method and device |
US20050064920A1 (en) * | 2003-09-22 | 2005-03-24 | Tarang Luthra | Reducing interference in high speed home network using signal processing |
US7333787B2 (en) * | 2003-09-22 | 2008-02-19 | Tarang Luthra | Reducing interference in high speed home network using signal processing |
US20210351796A1 (en) * | 2019-03-15 | 2021-11-11 | Mitsubishi Electric Corporation | Decoding device, decoding method, control circuit, and storage medium |
US11539380B2 (en) * | 2019-03-15 | 2022-12-27 | Mitsubishi Electric Corporation | Decoding device, decoding method, control circuit, and storage medium |
Also Published As
Publication number | Publication date |
---|---|
US20010003088A1 (en) | 2001-06-07 |
US6308054B2 (en) | 2001-10-23 |
US6456830B2 (en) | 2002-09-24 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US6249669B1 (en) | Diversity wireless communication method and its wireless communication apparatus | |
US6456830B2 (en) | Diversity wireless communication method and its wireless communication apparatus | |
US6298462B1 (en) | Data transmission method for dual diversity systems | |
US6725411B1 (en) | Iterated soft-decision decoding of block codes | |
US6145110A (en) | Digital data decoder that derives codeword estimates from soft data | |
US7003042B2 (en) | Communication system transmitting encoded signal using block lengths with multiple integral relationship | |
US8054904B2 (en) | Partial iterative detection and decoding apparatus and method in MIMO system | |
US20050204273A1 (en) | Apparatus and method for encoding and decoding a space-time low density parity check code with full diversity gain | |
US10992416B2 (en) | Forward error correction with compression coding | |
WO2006093286A1 (en) | Wireless communication apparatus | |
US20070230609A1 (en) | Iterative detection and decoding apparatus and method in MIMO system | |
US6996762B2 (en) | Methods and apparatus of signal demodulation combining with different modulations and coding for wireless communications | |
US8359519B2 (en) | Cooperative transmission method and communication system using the same | |
US7877664B2 (en) | Apparatus and method for transmitting/receiving signal in communication system | |
US7218683B2 (en) | Channel encoding/decoding method and multiple-antenna communication transmitting/receiving system performing the same | |
US5365525A (en) | Method for reducing bandwidth of a wireline communication path | |
US10153865B2 (en) | Apparatus and method for transmitting and receiving data in communication system | |
US6678854B1 (en) | Methods and systems for providing a second data signal on a frame of bits including a first data signal and an error-correcting code | |
Luyi et al. | Forward error correction | |
US10396826B2 (en) | Software defined network with selectable low latency or high throughput mode | |
US8689090B2 (en) | Apparatus and method for channel encoding and decoding based on low-density parity check code in multiple antenna communication system | |
CN100486235C (en) | Iterative receiving method for maintaining soft information | |
EP1035662A2 (en) | Method and apparatus for wireless diversity communication | |
Deng et al. | An adaptive coding scheme with code combining for mobile radio systems | |
US10243696B2 (en) | Diversity combining of non-coherently modulated LDPC codes in wireless communications |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
FEPP | Fee payment procedure |
Free format text: PAYOR NUMBER ASSIGNED (ORIGINAL EVENT CODE: ASPN); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY |
|
REMI | Maintenance fee reminder mailed | ||
LAPS | Lapse for failure to pay maintenance fees | ||
STCH | Information on status: patent discontinuation |
Free format text: PATENT EXPIRED DUE TO NONPAYMENT OF MAINTENANCE FEES UNDER 37 CFR 1.362 |
|
FP | Lapsed due to failure to pay maintenance fee |
Effective date: 20060924 |