KR100977551B1 - Apparatus and method for controlling 1-bit sampler threshold of ultra-wideband impulse receiver - Google Patents

Abstract

The present invention discloses an apparatus and method for controlling a 1-bit sampler threshold of an ultra-wideband impulse receiver. An apparatus for controlling a 1-bit sampler threshold according to an embodiment of the present invention includes a receiver for receiving an ultra-wideband impulse (IR-UWB) signal for data encoded with a balance code, and the second received by the receiver. A 1-bit sampler for converting a wideband impulse signal into 1-bit digital data and outputting it, calculating a specific gravity based on the state value of the 1-bit digital data output from the 1-bit sampler, and based on the calculated specific gravity And a controller configured to calculate a threshold of the 1-bit sampler and a controller to set the calculated threshold of the 1-bit sampler to the threshold of the 1-bit sampler.

Ultra-Wide Impulse (IR-UWB), 1-Bit Sampler, Threshold, Balance Code

Description

1-bit sampler threshold control device of ultra-wideband impulse receiver and its method {APPARATUS FOR CONTROLLING THRESHOLD OF 1-BIT SAMPLER IN IMPULSE-RADIO-BASED ULTRA WIDE BAND RECEIVER AND METHOD THEREOF}

TECHNICAL FIELD The present invention relates to threshold control, and in particular, an ultra-wideband impulse receiver receives an ultra-wideband impulse signal encoded with a balance code, and converts 1-bit digital data to an ultra-wideband impulse signal converted by a 1-bit sampler. An apparatus and method for controlling a 1-bit sampler threshold of an ultra-wideband impulse receiver capable of setting a threshold of a 1-bit sampler based on a state value and simplifying a hardware configuration and reducing manufacturing costs.

In general, the term 'wideband communication' in a communication system refers to a communication method having a wide modulation band that enables high-speed data communication.

In addition, unlike broadband communication, as a term for a non-carrier, baseband, or impulse communication method, an ultra-wideband impulse (IR-UWB) communication method has been used since the 1960s.

The IR-UWB communication method is not a method of transmitting an impulse-type signal having a pulse width of several [ns] to several tens of [ps] on a sine wave, but by directly transmitting and receiving an impulse, which is a characteristic of the broadband frequency of the pulse itself. The frequency appears over broadband.

Since the IR-UWB communication uses a very short pulse, the signal is transmitted using a wider bandwidth (number [Hz] to number [GHz]) than the data modulation band, and thus the power spectrum density. Can be made very low to reduce the effects of interference.

The system using IR-UWB communication method is very strong in multipath fading because it uses impulse, and the baseband signal is modulated by impulse string and transmitted directly, thus making the system simple and inexpensive.

These IR-UWB receivers require high-end analog-to-digital converters (ADCs) to detect a few [ns] of impulse signals and restore them to digital signals, which is a major factor in increasing receiver power consumption and complexity. .

As an alternative to solve this problem, a method using a 1-bit sampler (or 1-bit ADC) has been proposed, and the paper has proved that the performance can be approximated to a receiver using a full resolution ADC. (See (1) and (2)).

(1) S. Hoyos, B. Sadler, G. Arce. "Monobit Digital Receivers for Ultrawideband Communications", IEEE Trans on Wireless Comm., Vol. 4 (4), pp. 1337-1344, 2005.

(2) H. J. Lee, D. S. Ha and H. S. Lee, "Toward digital UWB radios: part I-frequency domain UWB receiver with 1 bit ADCs", Ultra Wideband Systems, 2004. Joint with Conference on Ultrawideband Systems and Technologies. Joint UWBST & IWUWBS. 2004 International Workshop on, pp. 248-252, May 2004.

In order to achieve full-resolution ADC performance using a 1-bit sampler, an appropriate threshold must be set for the 1-bit sampler. These thresholds must be set in order to achieve optimal bit error rate (BER) performance. However, it should be able to be actively adjusted to change in signal strength.

In the conventional method of estimating the threshold value of the ADC, after measuring the energy of the impulse signal and the noise of the received signal for a predetermined period, each representative value is determined, and the threshold value is obtained by substituting the determined representative value into an approximated probability model. .

However, a high-resolution ADC is required to measure the energy of an impulse signal and noise, and a 1-bit sampler is used because the sampling rate of the ADC must be fast to accurately measure the energy level of a very short impulse signal. There is an unsuitable problem.

An object of the present invention was devised to solve the above problems, and outputs an ultra-wideband impulse signal of data encoded by a balance code as 1-bit digital data using a 1-bit sampler, and outputs 1-bit digital data. An apparatus and method for controlling a 1-bit sampler threshold of an ultra-wideband impulse receiver capable of simplifying a structure and reducing hardware complexity by setting a threshold of a 1-bit sampler based on a state value of data.

Another object of the present invention is to provide a 1-bit sampler threshold control apparatus of an ultra-wideband impulse receiver capable of reducing the manufacturing complexity of the ultra-wideband impulse receiver by reducing the hardware complexity and controlling the threshold of the 1-bit sampler using only a digital circuit. To provide a method.

In order to achieve the above object, a 1-bit sampler threshold control device according to an aspect of the present invention includes a receiver for receiving an ultra-wideband impulse (IR-UWB) signal for data encoded with a balance code; A 1-bit sampler for converting the ultra-wideband impulse signal received by the receiver into 1-bit digital data to be optimized for 1-bit transmission; The bias weight ratio is calculated based on the first state value and the second state value of the 1-bit digital data output from the 1-bit sampler, and the first state of the 1-bit digital data is calculated based on the calculated weight ratio. A calculator for calculating a threshold value of the 1-bit sampler such that a ratio of the number of the value and the second state value is the same; And a controller configured to set the calculated threshold of the 1-bit sampler to the threshold of the 1-bit sampler.

In this case, the 1-bit sampler threshold control apparatus may further include a decoding unit for decoding and outputting the 1-bit digital data output from the 1-bit sampler into the balance code.

In this case, the specific gravity may be calculated by converting the first state value and the second state value of the 1-bit digital data into mapping values corresponding to the first state value and adding the converted mapping values.

delete

A 1-bit sampler threshold control method according to an aspect of the present invention comprises the steps of: receiving an ultra-wideband impulse signal for data encoded with a balance code; Converting the received ultra-wideband impulse signal into 1-bit digital data using a 1-bit sampler to optimize for 1-bit transmission; Calculating a specific gravity based on a first state value and a second state value of the converted 1-bit digital data; Calculating a threshold of the 1-bit sampler such that the ratio of the number of the first state value and the second state value of the 1 bit digital data is equal based on the calculated specific gravity; And setting the calculated threshold of the 1-bit sampler to the threshold of the 1-bit sampler.

In this case, the calculating of the specific gravity may include converting the first specific gravity value into a mapping value corresponding to each of the first state value and the second state value of the 1-bit digital data; And calculating the specific gravity based on the converted mapping value.

The present invention outputs an ultra-wideband impulse signal of data encoded by a balance code using 1-bit sampler as 1-bit digital data, and threshold value of 1-bit sampler based on the state value of the output 1-bit digital data. By setting this, the structure can be simplified to lower the hardware complexity.

The present invention has the effect of lowering the hardware complexity and lowering the manufacturing cost of the ultra-wideband impulse receiver by controlling the threshold of the 1-bit sampler using only digital circuits.

Other objects and features of the present invention in addition to the above objects will be apparent from the description of the embodiments with reference to the accompanying drawings.

Hereinafter, an apparatus and method for controlling a 1-bit sampler threshold of an ultra-wideband impulse receiver according to an embodiment of the present invention will be described in detail with reference to FIGS. 1 to 3.

1 is a block diagram of an ultra-wideband impulse device including a 1-bit sampler threshold control device according to an embodiment of the present invention.

Referring to FIG. 1, an ultra-wideband impulse device includes a transmitter 110 for transmitting an ultra-wideband impulse signal and a receiver 120 including a 1-bit sampler threshold control device according to the present invention.

The transmitter 110 includes a first encoder 131, a second encoder 132, and a transmitter 140, and the receiver 120 includes a calculator 150, a 1-bit sampler 160, and a receiver ( 170, a controller 180, a second decoder 192, and a first decoder 191.

The first encoding unit 131 outputs the encoded data through encoding using source encoder included in the first encoding unit 131, for example, a forward error correction (FEC) encoder.

Here, the encoder included in the first encoding unit 131 may include not only an FEC encoder but also all encoders that can be used in ultra-wideband communication such as a Viterbi encoder, a turbo code encoder, and a convolution encoder. .

The second encoder 132 outputs the balance code encoded data encoded by the first encoder 131. That is, the data output through the second encoding unit 132 outputs encoded data having the same composition ratio of "0" and "1".

Here, the second encoding unit 132 preferably includes a balance code encoder, and the amount of data encoded by the balance code encoder is preferably preset.

The transmitter 140 receives the balance code encoded data output from the second encoder 132, modulates the balance code encoded data into an ultra-wideband impulse (IR-UWB) signal, and transmits a transmission antenna (not shown). Send through).

The receiver 170 receives and outputs an ultra-wideband impulse signal through a reception antenna (not shown).

In this case, the receiver 170 receives an ultra-wideband impulse signal through a channel, and the channel is a channel having the same probability of changing "0" and "1", which constitute the ultra-wideband impulse signal, that is, a binary symmetric channel (BSC). Can be. That is, the receiver 170 receives the ultra-wideband impulse signal through a channel having the same probability that the data of "0" can be changed to "1" and the probability of changing the data of "1" to "0".

The 1-bit sampler 160 converts the ultra-wideband impulse signal output from the receiver 170, that is, the ultra-wideband impulse signal for the data encoded with the balance code, into 1-bit digital data based on a preset threshold value. .

For example, the 1-bit sampler 160 outputs 1-bit digital data of a first state value (eg, "1") if the ultra-wideband impulse signal is greater than or equal to the threshold, and if the ultra-wideband impulse signal is less than the threshold. Outputs one bit digital data of a second state value (eg, "0").

That is, the state value of the 1-bit digital data output from the 1-bit sampler 160 depends on the threshold of the 1-bit sampler 160. In the present invention, the 1-bit digital data for a predetermined interval or a predetermined number is set. The threshold is to be controlled such that the ratio of the number of first state values and the number of second state values is equal.

The calculation unit 150 calculates the bias weight of the state value based on the state value of the 1-bit digital data output from the 1-bit sampler 160, and calculates the 1-bit sampler ( Calculate a threshold of 160).

In this case, the calculator 150 may convert the state value of the 1-bit digital data into a preset mapping value corresponding to the state value, and calculate the weighted gravity of the state value by adding the converted mapping values. For example, assuming that the mapping value of the first state value "1" is "+1" and the mapping value of the second state value "0" is "-1", the first state value is based on the value added by adding the mapping values. Alternatively, the specific gravity of the degree of bias of the second state value may be calculated.

Here, the calculation unit 150 may calculate the specific gravity of the state value based on a predetermined interval or a predetermined number of state values of the 1-bit digital data output from the 1-bit sampler 160, and the state value. The predetermined interval or the predetermined number for calculating the specific gravity of the E is preferably the data interval or the integer multiple of the number of data for which the balance code encoding is performed by the transmitter 110. For example, assuming that the second encoding unit 132 performs balanced code encoding on 100 binary data, the calculation unit 150 outputs 100 × N outputs from the 1-bit sampler 160 (here, N is a positive specific gravity of the state value based on the state value of the 1-bit digital data).

The calculation unit 150 outputs the first state value and the second state value of the 1-bit digital data for a predetermined period or a predetermined number, which are output from the 1-bit sampler 160 based on the calculated specific gravity of the state value. It is preferable to calculate the threshold value so that the ratio with respect to the number of.

Here, the calculated threshold value is a value obtained by adding a value for the weighted specific gravity to the threshold value of the previous section.

That is, the calculated threshold value may be expressed as shown in [Equation 1].

Here, TH _i refers to the calculated threshold value for the i-th interval, TH _i-1 refers to the (i-1) -th, that is, the threshold of the previous interval, S _i is 1-bit digital data in the i-th interval The mapping values for the state values of are added, and f (S _i ) is the specific gravity of the state value for the i-th interval.

In this case, f (S _i ) may be a monotonic increase function.

That is, as shown in Equation 1, the calculation unit 150 calculates the weighted specific gravity of the state value as f (S _i ) using the sum of the mapping values in the i-th section, and then calculates the calculated f By adding the (S _i ) value to the threshold of the previous section, the threshold of the i-th section may be calculated.

f (S _i ) has a positive value when the state value in a predetermined interval is biased to the first state value "1", and a negative value when the state value is biased to the second state value "0", When the specific gravity of the first state value and the second state value is the same, it is preferably "0".

For example, when the number of state values in the i-th period is M, the mapping value of the first state value is "+1", and the mapping value of the second state value is "-1", the S _i value is at least "-M". , The maximum value may be "+ M". If the S _i value is close to "+ M", the calculation unit 150 needs to increase the threshold value because the 1-bit digital data is biased to the first state value "1". If the value of S _i is close to " -M, " the 1-bit digital data is biased to the second state value of " 0 " and the threshold must be lowered.

Of course, to increase the threshold level value f (S _i) lowering may vary depending on the value S _i, f may be changed according to the circumstances of the addition range (S _i) values.

The controller 180 sets the threshold calculated by the calculator 150 as the threshold of the 1-bit sampler 160. That is, the controller 180 resets the previous threshold value of the 1-bit sampler 160 to the threshold value calculated by the calculator 150 to reset the threshold value of the 1-bit sampler 160 by the controller 180. Based on the value, the state value of 1-bit digital data for the ultra-wideband impulse signal is output.

The second decoding unit 192 balance-codes and decodes the state value of the 1-bit digital data output by the 1-bit sampler 160 and outputs it.

The first decoding unit 191 is a decoder included in the first decoding unit 191, that is, the data encoded by the balance code decoding by the second decoding unit 192, that is, the data encoded by the first encoding unit 131. A decoder that can decode the data, for example, restores data through decoding using an FEC decoder.

Here, the decoder included in the first decoding unit 191 may include not only an FEC decoder but also all decoders that may be used in ultra-wideband communication such as a Viterbi decoder, a turbo code decoder, and a convolution decoder.

Of course, although not shown in Figure 1, it is apparent to those skilled in the art that control means for controlling the transmitter 110 and the receiver 120 of the ultra-wideband impulse device is provided.

As described above, the 1-bit sampler threshold control apparatus according to the present invention can control the threshold value of the 1-bit sampler based on the balance code and the state value output from the 1-bit sampler. The complexity can be lowered and the manufacturing cost of the ultra-wideband impulse receiver can be lowered.

2 is a flowchart illustrating a method of controlling a 1-bit sampler threshold according to an embodiment of the present invention.

Referring to FIG. 2, the 1-bit sampler threshold control method receives an ultra-wideband impulse signal for data encoded with a balance code through a channel (S210).

The received ultra-wideband impulse signal is converted into 1-bit digital data by a 1-bit sampler and output (S220).

Here, the 1-bit sampler converts the ultra-wideband impulse signal into one of a first state value and a second state value based on a threshold value and outputs the converted state. That is, the 1-bit sampler outputs a first state value "1" when the ultra-wideband impulse signal is greater than or equal to a threshold value, and outputs "0" which is a second state value when less than the threshold value. For example, as shown in FIG. 3, the 1-bit sampler outputs a first state value "1" because the k-th ultra-wideband impulse signal X _k 310 is greater than the threshold TH level, and ( Since the k + 1) th ultra-wideband impulse signal (X _{k + 1} ) 320 is smaller than the threshold value, the second state value “0” is output.

The state value of the 1-bit digital data output by the 1-bit sampler is converted into a corresponding mapping value (S230). Here, the mapping value may vary according to the state value of the 1-bit digital data. For example, when the state value of the 1-bit digital data is the first state value "1", the mapping value is converted to the mapping value "+1". When the state value of the 1-bit digital data is the second state value "0", the second state value is converted to the mapping value "-1".

A mapping value in a predetermined number or a predetermined interval is added, and the specific gravity weight of the state value is calculated based on the added mapping value (S240 and S250).

Here, the number of mapping values to be added is preferably a set number or a multiple of the interval when encoding data using a balance code.

In this case, the specific gravity of the state value may be calculated based on the size of the added mapping value. That is, assuming that the range of the added mapping value is from "-M" to "+ M", if the mapping value to which the predetermined number is added is close to "+ M", it is determined that the bias of the first state value "1" is severe. In order to make the ratio of the number of state values 1 and 2 equal, the threshold value currently set must be lowered. Therefore, the partial gravity weight value is calculated as a negative value corresponding to the added mapping value.

On the contrary, if the added mapping value is close to "-M", it is determined that the bias of the second state value "0" is severe, and the currently set threshold must be increased to make the ratio of the number of the first state value and the second state value equal. do. Therefore, the partial gravity weight value is calculated as a positive value corresponding to the added mapping value.

Of course, the weight specific gravity value according to the added mapping value may be calculated by f (S _i ) shown in Equation (1).

When the bias weight of the state value is calculated, a new threshold value is calculated based on the calculated bias weight and the currently set threshold of the 1-bit sampler (S260).

Here, the new threshold value may be calculated through Equation 1. That is, the new threshold value is calculated as a value obtained by adding the bias weight value calculated in step S250 to the currently set threshold value.

When the new threshold value is calculated, the calculated threshold value is set as the threshold value of the 1-bit sampler (S270).

The ultra-wideband impulse signal input to the 1-bit sampler after the new threshold is set outputs the state value of 1-bit digital data based on the newly set threshold.

Through this process, the threshold of the 1-bit sampler can be controlled.

Although the detailed description of the present invention resets the threshold of the 1-bit sampler at a predetermined number of data cycles, the timing of resetting the threshold may be different.

For example, the process of resetting the threshold value in the first period, using the threshold value set in the first period for a predetermined period, and resetting the threshold value in the next period may be repeated.

The 1-bit sampler threshold control apparatus and method thereof of the ultra-wideband impulse receiver according to the present invention can be modified and applied in various forms within the scope of the technical idea of the present invention and are not limited to the above embodiments. In addition, the embodiments and drawings are merely for the purpose of describing the contents of the invention in detail, not intended to limit the scope of the technical idea of the invention, the present invention described above is common knowledge in the technical field to which the present invention belongs As those skilled in the art can have various substitutions, modifications, and changes without departing from the spirit of the present invention, it is not limited to the embodiments and the accompanying drawings. And should be judged to include equality.

1 is a block diagram of an ultra-wideband impulse device including a 1-bit sampler threshold control device according to an embodiment of the present invention.

2 is a flowchart illustrating a method of controlling a 1-bit sampler threshold according to an embodiment of the present invention.

3 is an exemplary diagram for describing an output value of a 1-bit sampler according to a threshold value and an ultra-wideband impulse signal.

<Description of Symbols for Main Parts of Drawings>

131: first encoding unit

132: second encoding unit

140: transmitter

150: calculation unit

160: 1-bit sampler

170: receiver

180: control unit

191: first decoding unit

192, the second decoding unit

Claims (8)

A receiver for receiving an ultra-wideband impulse (IR-UWB) signal for data encoded with a balance code; A 1-bit sampler for converting the ultra-wideband impulse signal received by the receiver into 1-bit digital data to be optimized for 1-bit transmission; The bias weight ratio is calculated based on the first state value and the second state value of the 1-bit digital data output from the 1-bit sampler, and the first state of the 1-bit digital data is calculated based on the calculated weight ratio. A calculator for calculating a threshold value of the 1-bit sampler such that a ratio of the number of the value and the second state value is the same; And A controller configured to set the calculated threshold of the 1-bit sampler to the threshold of the 1-bit sampler Including; And a threshold value of the 1-bit sampler without the need for a high resolution analog-to-digital converter (ADC) for measuring the energy of the ultra-wideband impulse signal and the energy of noise. The method of claim 1, The 1-bit sampler threshold control device A decoding unit for decoding and outputting the 1-bit digital data output from the 1-bit sampler into the balance code And a 1-bit sampler threshold control device further comprising. The method of claim 1, The calculation unit 1-bit sampler threshold value, wherein the 1-bit sampler threshold value is converted into a mapping value corresponding to each of the first state value and the second state value of the 1-bit digital data, and the weighted specific gravity is calculated by adding the converted mapping value. controller. delete The method of claim 1, The calculation unit And calculating the specific gravity based on a first state value and a second state value of the 1-bit digital data output from the 1-bit sampler. Receiving an ultra-wideband impulse signal for data encoded with a balance code; Converting the received ultra-wideband impulse signal into 1-bit digital data using a 1-bit sampler to optimize for 1-bit transmission; Calculating a specific gravity based on a first state value and a second state value of the converted 1-bit digital data; Calculating a threshold of the 1-bit sampler such that the ratio of the number of the first state value and the second state value of the 1 bit digital data is equal based on the calculated specific gravity; And Setting the calculated threshold of the 1-bit sampler to the threshold of the 1-bit sampler Including; And a threshold value of the 1-bit sampler without the need for a high resolution analog-to-digital converter (ADC) for measuring the energy of the ultra-wideband impulse signal and the energy of noise. The method of claim 6, The step of calculating the specific gravity of the bias Converting the 1-bit digital data into mapping values corresponding to each of the first state value and the second state value; And Calculating the weighted specific gravity by adding the converted mapping values 1-bit sampler threshold control method comprising a. delete

Images