JP4637067B2 - Mobile receiver - Google Patents

Description

  The present invention relates to a reception technique in the field of digital broadcasting and digital transmission that employs an OFDM (Orthogonal Frequency Division Multiplexing) method, and more particularly, multi-band generated when receiving radio waves such as digital broadcasting and wireless local area network (LAN). The present invention relates to an adaptive array antenna technique and a diversity combining technique for removing the effects of path fading and interference waves.

  Examples of conventional adaptive array antenna technology and diversity combining technology include those described in Patent Literature 1 and Non-Patent Literature 1. Patent Document 1 prepares a plurality of fixed directivity patterns, compensates for the Doppler shift of the composite signal obtained from each directivity pattern, and then selects a plurality of signals having a large signal level to synthesize the maximum ratio. A method for performing the above has been proposed. Non-Patent Document 1 prepares a plurality of fixed directivity patterns, compensates for the Doppler shift of the combined signal obtained from each directivity pattern, and then performs maximum ratio combining using all the signals. A method has been proposed.

JP-A-9-199927 Pubudu Sampath WIJESENA, Yoshio KARASAWA, “Beam-Space Adaptive Array Antenna for Suppressing the Doppler Spred in OFDM Mobile Reception”, IEICE TRANS. COMMUN., VOL.E87-B, NO.1 Jan.2004.

  However, in the above-described method of Patent Document 1, since the maximum ratio combining is performed by selecting the signal level, the level difference between the desired wave and the unnecessary wave cannot be obtained, and the Doppler shift compensation accuracy decreases. It is assumed that the characteristics deteriorate. For this reason, there has been a problem that mobile reception characteristics cannot always be improved.

  Further, in Non-Patent Document 1 described above, since the maximum ratio combining is performed using all the combined signals, the number of inputs of the demodulator increases according to the number of directivity patterns, and the number of inputs of the demodulator is increased. There was a problem that it was not possible to cope with restrictions.

  Therefore, the present invention has been made to solve such a problem, and the object of the present invention is to reduce the compensation accuracy of the Doppler shift and to limit the number of inputs of the demodulator to the OFDM signal. It is an object of the present invention to provide a mobile receiver capable of mobile reception.

  As means for solving the above problems, the mobile receiver according to the present invention prepares a plurality of fixed directional patterns, compensates for the Doppler shift of the synthesized signal obtained from each directional pattern, and then performs MER ( By selecting a plurality of modulation error ratios (modulation error ratio) values and performing maximum ratio combining, mobile reception characteristics are improved.

  That is, a mobile receiver according to the present invention includes a plurality of antenna units that receive a plurality of incoming waves and a quadrature demodulator that demodulates the received signals of the incoming waves and obtains an IQ signal in the mobile receiver that receives OFDM signals A weight coefficient multiplier for calculating each synthesized signal obtained by complex multiplication of each IQ signal according to a plurality of fixed directivity patterns, and a Doppler frequency is estimated from each synthesized signal. An AFC (Auto Frequency Control) unit that compensates for a shift; a MER measuring unit that measures a MER (Modulation Error Ratio) of each output signal of the AFC unit compensated for the Doppler shift; Among the MER values, MER values corresponding to a predetermined number are selected in order from the maximum value, and the pre-equalization data signal corresponding to each MER value and S A signal selection unit that selects a transmission line characteristic obtained from (scattered pilot) and a weighting factor are calculated using the selected transmission line characteristic, and the selected pre-equalization data signal is calculated. A carrier combining diversity unit that performs complex multiplication of weighting coefficients and a demapping unit that performs demapping on the combined data signal are provided.

  In the mobile reception device according to the present invention, the MER measurement unit measures the MER of each output signal of the AFC unit compensated for Doppler shift for each carrier, and the signal selection unit performs each MER value for each carrier. MER values of a preset number are selected in order from the maximum value, and a pre-equalization data signal corresponding to each MER value and a transmission path characteristic obtained from SP are selected. And

  In the mobile receiver according to the present invention, the MER measuring unit measures the MER of each output signal of the AFC unit compensated for Doppler shift for each group (group carrier) of a plurality of carriers, and The selection unit selects, for each group carrier, MER values corresponding to a predetermined number in order from the maximum value among the MER values, and the data signal before equalization corresponding to each MER value, and SP The transmission path characteristics obtained from the above are selected.

  Further, in the mobile receiver according to the present invention, the MER measuring unit may be configured for each carrier or each of a plurality of carriers from one subcarrier to all bands in the frequency direction of the OFDM signal that is a received signal, and The MER is measured for each symbol or for each of a plurality of symbols in the time direction of the OFDM signal that is a received signal, and the signal selection unit preliminarily starts from the maximum value among the MER values in advance for each carrier and each symbol. It is characterized by selecting a set number of MER values, and selecting a pre-equalization data signal corresponding to each MER value and a transmission path characteristic obtained from SP.

  The mobile reception apparatus according to the present invention is a carrier combining diversity unit in which the carrier combining diversity unit updates a weighting coefficient using an RLS (Recursive Least Squares) algorithm, and uses the RLS algorithm. A SP weight coefficient updating unit that updates the SP weight coefficient, a first complex multiplication of the SP weight coefficient and the SP signal selected by the signal selection unit among the SPs extracted from the output signals of the AFC unit. And calculating an error between the known SP signal and the SP signal complex-multiplied by the first complex multiplier, and the SP weight. An error calculation unit that causes the coefficient update unit to update the SP weight coefficient using the error, and an SP signal that is complex-multiplied by the first complex multiplier A symbol filter unit that performs interpolation processing in the direction, a carrier filter unit that performs interpolation processing in the frequency direction with respect to the output signal of the symbol filter unit, and a data signal before equalization selected by the signal selection unit A second complex multiplier for complexly multiplying the weighting coefficient, and an adder for adding each signal complex-multiplied by the second complex multiplier.

  According to the mobile receiver of the present invention, a plurality of signals are selected from those having a large MER value, and the maximum ratio synthesis is performed on the selected signals. As a result, the accuracy of Doppler shift compensation does not decrease. Also, in the mobile receiver according to the present invention, a plurality of signals having a large MER value are selected in order from the number of signals corresponding to the number of received signals input in the orthogonal transform unit, and the maximum ratio combining is performed. In addition, mobile reception can be realized without being limited by the number of input received signals in the orthogonal demodulation unit. Therefore, it is possible to improve mobile reception characteristics when receiving an OFDM signal.

The best mode for carrying out the present invention will be described below in detail with reference to the drawings.
[Example 1]
First, Example 1 will be described. FIG. 1 is a diagram showing a system configuration of Embodiment 1 in a mobile reception apparatus of the present invention. The mobile receiver 1 includes an antenna unit 10, an orthogonal demodulation unit 20, a weighting factor multiplication unit 30, an AFC (Auto Frequency Control) unit 40, a MER measurement unit 50, a signal selection unit 60-1, a carrier synthesis diversity. Part 70-1 and demapping part 80. The AFC unit 40 is composed of n AFC units. Since the individual AFC units have the same configuration, the individual AFC units are also referred to as the AFC units 40 in the following description. The same applies to the MER measuring unit 50.

The antenna unit 10 is composed of K antennas arranged in various shapes (linear array, rectangular array, circular array, etc.). Each antenna receives a plurality of incoming waves, and each output signal (RF ₁ , RF ₂ ,..., RF _K ) are sent to the orthogonal demodulation unit 20.

  The quadrature demodulator 20 has a function of demodulating the received signal and generating an IQ signal. FIG. 2 is a diagram illustrating a configuration of the orthogonal demodulation unit 20 illustrated in FIG. The quadrature demodulator 20 includes a BPF 21 composed of K BPFs (Band Pass Filters), a common local signal generator 22, a distributor 23, a quadrature detector 24 composed of K detectors, and K The LPF unit 25 is composed of an LPF (Low Pass Filter).

In the orthogonal demodulation unit 20, each output signal (RF ₁ , RF ₂ ,..., RF _K ) from the antenna unit 10 passes through the BPF unit 21. The common local signal is generated from the common local signal generation unit 22 and is equally distributed to K by the distribution unit 23. The quadrature detection unit 24 multiplies the signal that has passed through the BPF unit 21 by the common local signal equally distributed by the distribution unit 23 (orthogonal demodulation), and the complex baseband IQ for the number of installed antennas (K). Get a signal. The complex baseband IQ signal is band-limited by the LPF unit 25, and each output signal (EL ₁ , EL ₂ ,..., EL _K ) is sent to the weighting factor multiplier 30.

  The weighting coefficient multiplication unit 30 has a function of calculating each composite signal obtained by a plurality of fixed directivity patterns. FIG. 3 is a diagram showing a configuration of the weighting coefficient multiplication unit 30 shown in FIG. The weighting factor multiplication unit 30 includes a weighting factor unit 31 having n directivity patterns, a multiplication unit 32 including K × n multipliers, and an addition unit 33 including n adders. .

In the weighting factor multiplication unit 30, the multiplication unit 32 applies each of the output signals (EL ₁ , EL ₂ ,..., EL _K ) from the orthogonal demodulation unit 20 to n directivity patterns from the weighting factor unit 31. each weighting factor according _{(W 11, W 12, ···} , W 1K), (W 21, W 22, ···, W 2K), ···, (W n1, W n2, ···, W _nK ). The adding unit 33 adds K signals multiplied by the complex corresponding to each element of the weight coefficient unit 31, and sends each output signal (BP ₁ , BP ₂ ,..., BP _n ) to the AFC unit 40. It is done.

  The AFC unit 40 has a function of estimating the Doppler frequency after receiving and arriving waves according to each directivity pattern. FIG. 4 is a diagram showing the configuration of the AFC unit 40 shown in FIG. There are many methods for estimating the Doppler frequency by the AFC unit, but an example will be described here. The AFC unit 40 includes effective symbol length delay units 41 and 42, multiplication units 43 and 44, moving average units 45 and 46, a Doppler frequency calculation unit 47, and a frequency shift correction unit 48.

In the AFC unit 40, the multiplication unit 43 multiplies (correlates) the I-axis data of the output signal from the weight coefficient multiplication unit 30 with the I-axis data delayed by the effective symbol length delay unit 41 by the effective symbol period. . The moving average unit 45 takes a moving average for the guard interval period for the signal multiplied by the multiplication unit 43, generates a signal Sii (i), and sends the signal Sii (i) to the Doppler frequency calculation unit 47. The multiplier 44 multiplies the I-axis data of the output signal from the weight coefficient multiplier 30 by the Q-axis data delayed by the effective symbol length delay unit 42 for the effective symbol period (takes correlation). The moving average unit 46 takes a moving average for the guard interval period for the signal multiplied by the multiplication unit 44, generates a signal Siq (i), and sends it to the Doppler frequency calculation unit 47. The Doppler frequency calculation unit 47 calculates the Doppler frequency for each symbol using the equations in FIG. 4 based on the signals Sii (i) and Siq (i). The frequency deviation correction unit 48 uses the Doppler frequency for each symbol calculated by the Doppler frequency calculation unit 47 to correct the frequency deviation corresponding to the Doppler frequency of the output signal from the weight coefficient multiplication unit 30 by, for example, a frequency offset circuit. To do. AFC unit 40, these same processing is performed n number fraction corresponding to the number of directional patterns, the output signal Doppler shift is compensated (AFC _1, AFC _2, · · ·, AFC _n) is MER measurement unit 50.

The MER measuring unit 50 has a function of measuring the MER of each output signal (AFC ₁ , AFC ₂ ,..., AFC _n ) in which the Doppler shift from the AFC unit 40 is compensated. FIG. 5 is a diagram showing a configuration of the MER measuring unit 50 shown in FIG. The MER measurement unit 50 includes an FFT (Fast Fourier Transform) unit 51, an SP (Scattered Pilot) extraction unit 52, an SP generation unit 53, an SP complex division unit 54, a symbol filter unit 55, and a carrier filter unit 56. , A complex division unit 57, and a MER calculation unit 58.

  In the MER measurement unit 50, the SP extraction unit 52 extracts the SP from the data signal after the output signal compensated for the Doppler shift from the AFC unit 40 is FFTed by the FFT unit 51. The SP complex division unit 54 performs complex division (SP complex division) on the SP extracted by the SP extraction unit 52 by the transmission-side known SP generated by the SP generation unit 53. Thereby, the transfer function (amplitude and phase) of the position of the SP is obtained. By using a two-dimensional filter composed of a time-direction symbol filter unit 55 and a frequency-direction carrier filter unit 56, the transmission path characteristics of all carriers including the data carrier of the entire band are obtained by the transfer function (amplitude and phase) of the SP position. presume. The complex division unit 57 equalizes (complex division) the data signal FFTed by the FFT unit 51 with the transmission path characteristics estimated using the two-dimensional filter. The MER calculator 58 calculates the MER of each carrier from the data signal equalized by the complex divider 57 using the equation in FIG.

In addition, the data signal before equalization and the transmission path characteristics obtained from the SP are output as MER-DATA and MER-SP, respectively, for use in the carrier combining diversity unit 70-1 described later. The MER measuring unit 50 performs the same processing as described above for n directivities corresponding to the number of directivity patterns, and data signals before equalization (MER-DATA ₁ , MER-DATA ₂ ,..., MER-DATA _n ). , Transmission path characteristics obtained from SP (MER-SP ₁ , MER-SP ₂ ,..., MER-SP _n ), and MER value (MER ₁ (x, y), MER ₂ (x, The output signals y),..., MER _n (x, y)) are sent to the signal selector 60-1.

  Here, data arrangement in the frequency (carrier) direction and time (symbol) direction in MER (x, y) will be described with reference to FIG. Various values of MER (x, y) can be obtained depending on the resolution in the frequency direction x and the resolution in the time direction y. Assuming that the total number of data carriers in the frequency direction in terrestrial digital broadcasting is Kcar, x = Kcar when calculating MER for all bands, and x = 1 when calculating MER for each carrier. When calculating the MER for all bands, Kcar MER values calculated for each carrier are added. On the other hand, when calculating the MER for each symbol in the time direction, y = 1, and when calculating the MER for every 10 symbols, y = 10. When calculating the MER for every 10 symbols, the MER value calculated for each symbol is added for 10 symbols. As described above, x and y according to the mobile reception environment can be set.

The signal selection unit 60-1 determines the maximum of each MER value (MER (x, y) ₁ , MER (x, y) ₂ , ..., MER (x, y) _n ) measured by the MER measurement unit 50. In order from the value, up to m inputs to a carrier synthesis diversity unit 70-1, which will be described later, are selected, and the pre-equalized data signal (MER-DATA ₁ , MER-DATA ₂ ) corresponding to the MER (x, y) value is selected. has ···, MER-DATA _n), the transmission path characteristics determined from _{SP (MER-SP l, MER} -SP 2, ···, a function of selecting the MER-SP _n). FIG. 7 is a diagram illustrating a configuration of the signal selection unit 60-1 illustrated in FIG. This signal selection unit 60-1 shows the case of MER (x, y) where x = Kcar (the number of data carriers in the entire band). The MER determination unit 61-1 and the signal selection unit 62-1 (MER− A portion for selecting DATA) and a signal selection unit 63-1 (a portion for selecting MER-SP).

In the signal selection unit 60-1, the MER determination unit 61-1 inputs each MER (x, y) value, adds MER (x, y) values for y symbols, and then sequentially sets n from the maximum value. Rearranging (sorting process) up to m and outputting m of the rearranged n to the signal selection units 62-1 and 63-1. The signal selection unit 62-1 selects each data signal corresponding to m MER (x, y) values, and the data signal (MRC-DATA _l , MRC-DATA ₂ ,..., MRC-DATA _m ). Are output to the carrier combining diversity unit 70-1. Further, the signal selection unit 63-1 selects each SP signal corresponding to m MER (x, y) values, and SP signals (MRC-SP ₁ , MRC-SP ₂ ,..., MRC-SP). _m ) output signals are sent to the carrier combining diversity unit 70-1.

  The carrier synthesis diversity unit 70-1 has a function of generating a stable signal from a plurality of signals. FIG. 8 is a diagram showing a configuration of the carrier combining diversity unit 70-1 shown in FIG. The carrier combining diversity unit 70-1 includes a diversity weight calculating unit 71-1, m complex multipliers 72-1, and an adding unit 73-1.

In carrier combining diversity section 70-1, diversity weight calculating section 71-1 receives each MRC-SP and calculates a weight coefficient for m carrier combining diversity numbers using the formula in FIG. The complex multiplier 72-1 calculates each input signal (MRC-DATA _l , MRC-DATA ₂ ,..., MRC-DATA _m ) from the SP transmission path characteristics by the diversity weight calculator 71-1. The weighting coefficient is subjected to complex multiplication, and the adder 73-1 adds the complex multiplied signals. Then, the demapping unit 80 demaps the signal from the carrier synthesis diversity unit 70-1 (reallocates and generates a digital signal from the analog signal), thereby obtaining an output signal (DATA).

[Example 2]
Next, Example 2 will be described. In the second embodiment, the signal selection for all bands in the first embodiment is changed to signal selection for each carrier. FIG. 9 is a diagram illustrating a configuration of the signal selection unit 60-2 of the second embodiment in the mobile reception device of the present invention. The mobile reception apparatus according to the second embodiment includes an antenna unit 10, an orthogonal demodulation unit 20, a weight coefficient multiplication unit 30, an AFC unit 40, a MER measurement unit 50, a signal selection unit 60-2, a carrier combining diversity unit 70-1, and a demultiplexing unit. The mapping unit 80 is configured. Comparing the mobile reception device 1 of the first embodiment and the mobile reception device of the second embodiment shown in FIG. 1 with each other, the antenna unit 10, the quadrature demodulation unit 20, the weight coefficient multiplication unit 30, the AFC unit 40, and the MER. Although it is the same in that the measurement unit 50, the carrier combining diversity unit 70-1, and the demapping unit 80 are provided, the mobile reception device of the second embodiment is a signal instead of the signal selection unit 60-1 of the first embodiment. The difference is that a selection unit 60-2 is provided. Hereinafter, detailed description of the same parts as those in the first embodiment will be omitted. The signal selection unit 60-2 of the second embodiment shows a case where the signal selection unit 60-1 of the first embodiment has x = Kcar (number of data carriers in all bands) for MER (x, y). On the other hand, the case is shown for each carrier instead of the entire band.

The signal selection unit 60-2 calculates the maximum value of each MER value (MER (x, y) ₁ , MER (x, y) ₂ , ..., MER (x, y) _n ) measured by the MER measurement unit 50. In order from the value, up to m inputs to a carrier synthesis diversity unit 70-1 described later are selected, and the data signal before the equalization (MER-DATA _l , MER-DATA ₂ , MER) corresponding to the MER (x, y) value is selected. , MER-DATA _n ), and a function for selecting transmission path characteristics (MER-SP ₁ , MER-SP ₂ ,..., MER-SP _n ) obtained from SP. Referring to FIG. 9, this signal selection unit 60-2 shows the case of x = 1 (carrier) for MER (x, y), and Kcar MER determination units 61-2 for each carrier, It comprises a signal selection unit 62-2 (a part for selecting MER-DATA) and a signal selection unit 63-2 (a part for selecting MER-SP).

In the signal selection unit 60-2, the MER determination unit 61-2 adds MER (x, y) values for each carrier for y symbols, and then rearranges (sort processing) from the maximum value to n in order. , M of the rearranged n are output to the signal selectors 62-2 and 63-2. This process is performed for all Kcars according to the total number of carriers. The signal selection unit 62-2 selects each data signal corresponding to m MER (x, y) values for each carrier (for each Kcar carriers), and the data signal (MRC-DATA ₁ , MRC-DATA _2). ,..., MRC-DATA _m ) are sent to the carrier combining diversity unit 70-1. Further, the signal selection unit 63-2 selects each SP signal corresponding to m MER (x, y) values for each carrier (for each Kcar carriers), and the SP signal (MRC-SP ₁ , MRC-). SP ₂ ,..., MRC-SP _m ) are sent to the carrier combining diversity unit 70-1.

Example 3
Next, Example 3 will be described. In the third embodiment, the signal selection for all bands in the first embodiment is changed to signal selection for each group (group carrier) with a plurality of carriers as a unit. FIG. 10 is a diagram illustrating a configuration of the signal selection unit 60-3 of the third embodiment in the mobile reception device of the present invention. The mobile reception apparatus of the third embodiment includes an antenna unit 10, an orthogonal demodulation unit 20, a weight coefficient multiplication unit 30, an AFC unit 40, a MER measurement unit 50, a signal selection unit 60-3, a carrier combining diversity unit 70-1, and a demultiplexing unit. The mapping unit 80 is configured. Comparing the mobile reception device 1 of the first embodiment shown in FIG. 1 with the mobile reception device of the third embodiment, both devices include an antenna unit 10, an orthogonal demodulation unit 20, a weight coefficient multiplication unit 30, an AFC unit 40, and a MER. Although it is the same in that the measurement unit 50, the carrier synthesis diversity unit 70-1, and the demapping unit 80 are provided, the mobile reception device of the third embodiment is not limited to the signal selection unit 60-1 of the first embodiment. The difference is that a selection unit 60-3 is provided. Hereinafter, detailed description of the same parts as those in the first embodiment will be omitted. The signal selection unit 60-3 of the third embodiment shows a case where the signal selection unit 60-1 of the first embodiment has x = Kcar (number of data carriers in all bands) for MER (x, y). On the other hand, the case of not every band but every group carrier is shown.

The signal selection unit 60-3 calculates the maximum value of each MER value (MER (x, y) ₁ , MER (x, y) ₂ , ..., MER (x, y) _n ) measured by the MER measuring unit 50. In order from the value, up to m inputs to a carrier synthesis diversity unit 70-1, which will be described later, are selected, and the pre-equalized data signal (MER-DATA ₁ , MER-DATA ₂ ) corresponding to the MER (x, y) value is selected. ,..., MER-DATA _n ), and a function for selecting transmission path characteristics (MER-SP ₁ , MER-SP ₂ ,..., MER-SP _n ) obtained from the SP. Referring to FIG. 10, this signal selector 60-3 shows a case where x = X (for each group carrier, where X = Kcar / Z, Z is a prime number of Kcar) in MER (x, y). And MER determination unit 61-3, signal selection unit 62-3 (a part for selecting MER-DATA), and signal selection unit 63-3 (a part for selecting MER-SP).

In the signal selection unit 60-3, the MER determination unit 61-3 adds MER (x, y) values for y symbols for each group carrier, and then rearranges the n values in order from the maximum value (sort process). Then, m of the rearranged n pieces are output to the signal selectors 62-3 and 63-3. This process is performed for all X in accordance with the total number of groups. The signal selection unit 62-3 selects each data signal corresponding to m MER (x, y) values for each group carrier (for each X group carriers) and outputs the data signal (MRC-DATA _l , MRC- DATA ₂ ,..., MRC-DATA _m ) are sent to the carrier combining diversity unit 70-1. Further, the signal selection unit 63-3 selects each SP signal corresponding to the m MER (x, y) values for each group carrier (for each X group carriers), and the SP signal (MRC-SP _l , MRC-SP ₂ ,..., MRC-SP _m ) are sent to the carrier combining diversity unit 70-1.

Example 4
Next, Example 4 will be described. In the fourth embodiment, a weighting coefficient is calculated using an RLS (Recursive Least Squares) algorithm. FIG. 11 is a diagram illustrating a configuration of a carrier combining diversity unit (hereinafter referred to as an RLS update type carrier combining diversity unit) 70-2 that updates a weighting coefficient using the RLS algorithm according to the fourth embodiment in the mobile reception device of the present invention. It is. The mobile reception apparatus of the fourth embodiment includes an antenna unit 10, an orthogonal demodulation unit 20, a weight coefficient multiplication unit 30, an AFC unit 40, a MER measurement unit 50, a signal selection unit 60-1, an RLS update type carrier combining diversity unit 70-. 2 and a demapping unit 80. Comparing the mobile reception device 1 of the first embodiment shown in FIG. 1 with the mobile reception device of the fourth embodiment, both devices include an antenna unit 10, an orthogonal demodulation unit 20, a weight coefficient multiplication unit 30, an AFC unit 40, and a MER. Although it is the same in that the measurement unit 50, the signal selection unit 60-1, and the demapping unit 80 are provided, the mobile reception apparatus of the fourth embodiment is an RLS instead of the carrier combining diversity unit 70-1 of the first embodiment. The difference is that an update type carrier synthesis diversity unit 70-2 is provided. Hereinafter, detailed description of the same parts as those in the first embodiment will be omitted.

  The RLS update type carrier combining diversity unit 70-2 of the fourth embodiment has a function of generating a stable signal from a plurality of signals, like the carrier combining diversity unit 70-1 of the first embodiment shown in FIG. However, since the weighting coefficient is updated using the RLS adaptive algorithm as compared with the carrier combining diversity unit 70-1, the weighting coefficient is easily optimized, and it is considered that the inter-carrier interference due to mobile reception can be suppressed.

  The RLS update type carrier synthesis diversity unit 70-2 includes an SP weight coefficient update unit 71-2, m complex multipliers 72-2, an adder 73-2, m complex multipliers 74-2, and SP generation. Section 75-2, error calculation section 76-2, symbol filter section 77-2, and carrier filter section 78-2.

Here, the m number of SP signals (MRC-SP ₁ , MRC-SP ₂ ,..., MRC-SP _m ) input by the complex multiplication unit 74-2 from the signal selection unit 60-1 are the signal selection unit 60. 1 shows a signal selected by inputting the SP signal of the MER-SP extracted by the SP extraction unit 52 shown in FIG. 5 (the signal shown in FIG. 5 in the case of the fourth embodiment). ing. In the RLS update type carrier combining diversity unit 70-2, the complex multiplying unit 74-2 performs a complex multiplication on the input MER-SP by the initial weight coefficient from the SP weight coefficient updating unit 71-2, and each SP combined signal. Is sent to the error calculator 76-2. The error calculator 76-2 calculates an error between the known SP signal generated by the SP generator 75-2 and the SP composite signal, and the error component is sent to the SP weight coefficient updater 71-2. The SP weighting coefficient updating unit 71-2 updates the weighting coefficient W (i) using the formula in FIG.

The complex multiplication unit 74-2 performs complex multiplication on the input MER-SP by the final weight coefficient obtained after calculating all samples in one symbol section, and obtains each SP composite signal. Then, the symbol filter unit 77-2 performs an interpolation process on each SP composite signal in the time direction, and the carrier filter unit 78-2 performs an interpolation process on the frequency direction. Thereby, the transmission path characteristics of the entire band can be obtained. The complex multiplication unit 72-2 performs interpolation processing on each input signal (MRC-DATA ₁ , MRC-DATA ₂ ,..., MRC-DATA _m ) by the symbol filter unit 77-2 and the carrier filter unit 78-2. Each of the transmission line characteristics thus obtained is subjected to complex multiplication, and the adder 73-1 adds the complex-multiplied signals. The demapping unit 80 can obtain an output signal (DATA) by demapping the signal from the RLS update type carrier combining diversity unit 70-2.

  The present invention has been described with reference to the embodiments. However, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the technical idea thereof. For example, in the fourth embodiment, the mobile reception device includes the signal selection unit 60-1 of the first embodiment, but includes the signal selection unit 60-2 of the second embodiment instead of the signal selection unit 60-1. Alternatively, the signal selection unit 60-3 of the third embodiment may be provided.

It is a figure which shows the system configuration | structure of Example 1 in the mobile receiver of this invention. It is a figure which shows the structure of an orthogonal demodulation part. It is a figure which shows the structure of a weighting coefficient multiplication part. It is a figure which shows the structure of an AFC part. It is a figure which shows the structure of a MER measurement part. It is an arrangement | positioning figure which shows arrangement | positioning of SP and data of a frequency direction and a time direction. It is a figure which shows the structure of a signal selection part. It is a figure which shows the structure of a carrier synthetic | combination diversity part. It is a figure which shows the structure of the signal selection part of Example 2 in the mobile receiver of this invention. It is a figure which shows the structure of the signal selection part of Example 3 in the mobile receiver of this invention. It is a figure which shows the structure of the RLS update type | mold carrier synthetic | combination diversity part of Example 4 in the mobile receiver of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Mobile receiver 10 Antenna part 20 Orthogonal demodulation part 21 BPF part 22 Common local signal generation part 23 Distribution part 24 Orthogonal detection part 25 LPF part 30 Weight coefficient multiplication part 31 Weight coefficient part 32 Multiplication part 33 Addition part 40 AFC part 41, 42 Effective symbol length delay unit 43, 44 Multiply unit 45, 46 Moving average unit 47 Doppler frequency calculation unit 48 Frequency shift correction unit 50 MER measurement unit 51 FFT unit 52 SP extraction unit 53 SP generation unit 54 SP complex division unit 55 Symbol filter Unit 56 Carrier filter unit 57 Complex division unit 58 MER calculation unit 60-1 to 60-3 Signal selection unit 61-1, 61-2, 61-3 MER determination unit 62-1, 62-2, 62-3, 63 -1,63-2, 63-3 Signal selection unit 70-1 Carrier synthesis diversity unit 70-2 RL Update type carrier synthesis diversity unit 71-1 Diversity weight calculation unit 71-2 SP weight coefficient update unit 72-1 and 72-2 Complex multiplication unit 73-1 and 73-2 Addition unit 74-2 Complex multiplication unit 75-2 SP generator 76-2 Error calculator 77-2 Symbol filter unit 78-2 Carrier filter unit 80 Demapping unit

Claims (5)

In a mobile receiver that receives an OFDM signal,
A plurality of antenna units for receiving a plurality of incoming waves;
An orthogonal demodulator that demodulates the received signal of the incoming wave to obtain an IQ signal;
A weighting factor multiplier for calculating each synthesized signal obtained by complex multiplication of each weighting factor corresponding to a plurality of fixed directivity patterns on the IQ signal;
An AFC (Auto Frequency Control) unit for estimating a Doppler frequency from each synthesized signal and compensating for a Doppler shift;
A MER measuring unit that measures a MER (Modulation Error Ratio) of each output signal of the AFC unit compensated for the Doppler shift;
Among the MER values, MER values corresponding to a predetermined number are selected in order from the maximum value, and the data signal before equalization corresponding to each MER value and SP (Scattered Pilot: Scattered Pilot) are selected. ), A signal selection unit for selecting the transmission path characteristics obtained from
A carrier combining diversity unit that calculates a weighting factor using the selected transmission path characteristic, and combines the selected data signal before equalization by complex multiplication of the weighting factor;
A mobile reception apparatus comprising: a demapping unit that performs demapping on the synthesized data signal. The mobile receiver according to claim 1, wherein
The MER measurement unit measures the MER of each output signal of the AFC unit in which the Doppler shift is compensated for each carrier,
The signal selection unit selects, for each carrier, MER values corresponding to a predetermined number in order from the maximum value among the MER values, a data signal before equalization corresponding to each MER value, and A mobile receiver characterized by selecting a transmission path characteristic obtained from an SP. The mobile receiver according to claim 1, wherein
The MER measuring unit measures the MER of each output signal of the AFC unit in which the Doppler shift is compensated for each group (group carrier) having a plurality of carriers as a unit,
The signal selection unit selects, for each group carrier, MER values corresponding to a predetermined number in order from the maximum value among the MER values, and a data signal before equalization corresponding to each MER value, and A mobile receiver characterized by selecting transmission path characteristics obtained from SP. The mobile receiver according to claim 1, wherein
The MER measurement unit is configured for each carrier or every plurality of carriers in a frequency direction of an OFDM signal that is a received signal, from one subcarrier to a carrier in all bands, and in a time direction of the OFDM signal that is a received signal. Measure MER for each symbol or for each symbol,
The signal selection unit selects, for each carrier and each symbol, MER values for a preset number in order from the maximum value among the MER values, and data before equalization corresponding to each MER value A mobile receiving apparatus, wherein a transmission path characteristic obtained from a signal and an SP is selected. In the mobile receiver as described in any one of Claim 1 to 4,
The carrier synthesis diversity unit is
A carrier combining diversity unit that updates weighting coefficients using an RLS (Recursive Least Squares) algorithm,
An SP weighting factor updating unit that updates an SP weighting factor using the RLS algorithm;
A first complex multiplier that complex-multiplies the SP weighting factor with the SP signal selected by the signal selector from the SP extracted from each output signal of the AFC unit;
An SP generator for generating a known SP signal on the transmission side;
An error calculation unit that calculates an error between the known SP signal and the SP signal that is complex-multiplied by the first complex multiplication unit, and causes the SP weight coefficient update unit to update the SP weight coefficient using the error;
A symbol filter that performs interpolation processing in the time direction on the SP signal that is complex-multiplied by the first complex multiplier;
A carrier filter unit that performs interpolation processing in the frequency direction on the output signal of the symbol filter unit;
A second complex multiplier for complex multiplying a data signal before equalization selected by the signal selector with a weighting factor;
A mobile receiver comprising: an adder that adds the signals complex-multiplied by the second complex multiplier.

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