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Frequency error detection device, frequency error detection method and receiving device

A frequency error and receiving device technology, which is applied in the field of frequency error detection devices, frequency error detection and receiving devices, can solve the problems of symbol timing error detection range limitation, lack of practicability, and large amount of IDFT calculations, etc., and achieve low power consumption , the effect of reducing the amount of computation

Inactive Publication Date: 2016-12-28
MITSUBISHI ELECTRIC CORP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0009] The digital broadcast receiving device disclosed in Patent Document 1 uses IDFT (Inverse Discrete Fourier Transform) to detect frequency errors, so the IDFT requires a large amount of computation, and frequency error detection takes time.
Alternatively, when the first frequency error detector and the second frequency error detector are implemented as hardware, there is a problem that the circuit configuration is easily enlarged.
[0010] On the other hand, in the OFDM demodulation device disclosed in Patent Document 2, the reference signal for each specific subcarrier must be stored in the memory in advance. If a plurality of reference signals are not prepared in advance, the detection range of the symbol timing error will be limited. restricted
Therefore, the method of Patent Document 2 has a problem of lack of practicality

Method used

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  • Frequency error detection device, frequency error detection method and receiving device
  • Frequency error detection device, frequency error detection method and receiving device
  • Frequency error detection device, frequency error detection method and receiving device

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Embodiment approach 1

[0038] figure 1 It is a functional block diagram showing a schematic configuration of the receiving device according to Embodiment 1 of the present invention. Such as figure 1 As shown, the reception device 1 of the present embodiment includes a reception antenna element Rx, a tuner unit 11 , an A / D converter (ADC) 12 , a local oscillator 13 , and a quadrature demodulation unit 14 .

[0039] The tuner unit 11 receives radio signals via the receiving antenna element Rx. The tuner unit 11 performs analog signal processing such as tuning processing on the wireless signal to generate an analog reception signal of a carrier frequency band, and outputs the analog reception signal to the A / D converter 12 . The A / D converter 12 converts the analog reception signal in the carrier frequency band into a digital reception signal, and outputs it to the quadrature demodulation unit 14 . The digital reception signal is a multicarrier signal generated by digitally modulating and multiple...

Embodiment approach 2

[0104] Next, Embodiment 2 of the present invention will be described. Embodiment 2 is a modified example of Embodiment 1 described above. In Embodiment 1, the synchronization symbols corresponding to all N subcarriers are processed, but only synchronization symbols in a predetermined range of subcarriers can be processed. In this case, a further effect of reducing the amount of computation can be achieved. For example, when synchronous symbols corresponding to half of the N subcarriers are processed, the amount of computation can be further reduced to half.

[0105] Figure 10 is the sync symbol G(f that will correspond to every other subcarrier 0 ), G (f 2 ), G (f 4 ), G (f 6 ), ... as a graph of the state of the processing object. In this case, Figure 5 The first signal delay unit 46 delays the synchronization symbol serially input to the first complex arithmetic unit 32 by two subcarriers. When the synchronization symbol G (f k ), the first signal delay unit 46 o...

Embodiment approach 3

[0118] Next, Embodiment 3 of the present invention will be described. Figure 11 It is a functional block diagram showing a schematic configuration of the first frequency error detection unit 21B in the third embodiment. Such as Figure 11 As shown, the first frequency error detection unit 21B has a synchronization symbol extraction unit 31 , a first complex number calculation unit 32 , a reference signal supply unit 33B, a correlation calculation unit 36 ​​and a peak detection unit 37 . The configuration of the reception device according to this embodiment is the same as that of the reception device 1 according to the first embodiment except for the first frequency error detection unit 21B.

[0119] Such as Figure 11 As shown, the reference signal supply unit 33B includes the above-mentioned reference complex signal R (f k ) of the signal storage unit 34B. The signal storage unit 34B can combine the multiplication signal D (f k ) corresponding to the reference complex s...

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Abstract

The invention provides a frequency error detection device, a frequency error detection method and a receiving device, capable of detecting carrier frequency errors with less computation. The first frequency error detection unit (21) has a known signal extraction unit (31) for extracting a received known signal from a complex symbol signal, and performs a first complex operation on a sequence of received known signals to eliminate a phase rotation component part (32), a reference signal supply part (33) that provides a sequence of reference complex signals generated by performing the same operation as the first complex operation on the sequence of known signals, and calculates the output sequence of the complex operation part and the reference A correlation calculation unit (36) for distribution of cross-correlation values ​​between sequences of complex signals, and a peak detection unit (37) for detecting a distribution having a maximum peak value from these distributions to detect a carrier frequency error.

Description

technical field [0001] The present invention relates to a technique for receiving a signal transmitted by frequency division multiplexing using a plurality of subcarriers and detecting an error contained in the received signal. Background technique [0002] In general, in a receiver that performs quadrature demodulation on a received signal in the carrier frequency band (carrier frequency range) to generate a baseband received signal in the base band, when the carrier frequency used in the quadrature demodulation and the carrier wave of the received signal When there is an error between frequencies (hereinafter also referred to as "frequency error"), the transmitted data may be incorrectly reproduced. Therefore, this receiver has the function of detecting frequency errors and correcting them. [0003] Orthogonal Frequency Division Multiplexing (OFDM: Orthogonal Frequency Division Multiplexing) is a method of digitally modulating and multiplexing multiple subcarriers (subcar...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H04L27/26H04L27/227
CPCH04L27/266H04L27/2672H04L27/2675H04L27/2684H04L2027/003H04L2027/0053H04L2027/0065H04L2027/0085H04L2027/0095
Inventor 前田尚利
Owner MITSUBISHI ELECTRIC CORP