CN106549690A - Power carrier communication system auto gain control method and device - Google Patents

Abstract

The present invention discloses a kind of power carrier communication system auto gain control method and device.Methods described includes：Search the maximum and minima in continuous N number of ADC quantized values；Calculate the difference of difference and the minima of the maximum with full scale quantized value and minimum range quantized value；Calculate less one in 2 differences；Calculate relative value of the less difference relative to 50% full scale quantized value；It is otherwise 0 the super upper limit to be put when the relative value is more than upper limit threshold and is masked as 1, and it is otherwise 0 lower limit to be set low when less than lower threshold and is masked as 1；As the continuous N of super upper limit mark_overIt is secondary to reduce one gear of yield value when being all 1, as the continuous N of low limit mark_sagIt is secondary when being all 1, increase one gear of yield value.The present invention has very strong immunocompetence, while complexity is low being easily achieved in the case of low signal-to-noise ratio to impulsive noise.

Description

Power carrier communication system auto gain control method and device

Technical field

The present invention relates to power-line carrier communication field, more particularly to a kind of power carrier communication system automatic gain Control method and device.

Background technology

Power line carrier communication (Power Line Communication) abbreviation PLC, is the distinctive communication of power system Mode, refers to a kind of data transmission technology by the use of existing electric lines of force as communication media, and it is by information data to be transmitted Be modulated at and be suitable in the carrier signal of power line medium transmission, and along power line transmission, receiving terminal by demodulation carrier signal come Recover original information data.

On electric lines of force, the distance difference of different communication unit module is larger, the huge difference for thus bringing carrier signal to decay It is different；Due to impedance mismatch, carrier signal occurs the complicated phenomenons such as reflection, standing wave, and this causes electric lines of force attenuation characteristic more It is complicated；

On the other hand, colored background noise, arrowband interference noise, periodic pulse noise and random are there is on electric lines of force The various noises such as impulsive noise, noise instantaneous power are usually much higher than carrier signal power, traditional automatic growth control skill Art in this case, can carry out the adjustment of gain according to the change of noise power so that the carrier wave letter fallen into oblivion by noise There is saltus step in number amplitude, receives demodulation signal to noise ratio and further deteriorates.

Additionally, traditional automatic gain control be ensure gain control stability, typically by power, energy or Virtual value etc. carries out feedback control, is required to multiplying, when ADC sample frequencys are very high, power consumption and larger.

The content of the invention

To solve existing automatic gain control problem present in power carrier communication system, the present invention provides one Plant power carrier communication system auto gain control method.

For achieving the above object, the present invention is achieved through the following technical solutions：

A kind of power carrier communication system auto gain control method, it is characterised in that comprise the following steps：

Search the maximum and minima in continuous N number of ADC quantized values；

Calculate the difference of difference and the minima of the maximum with full scale quantized value and minimum range quantized value Value；

Calculate less one in 2 differences；

Calculate relative value of the less difference relative to 50% full scale quantized value；

It is otherwise 0 the super upper limit to be put when the relative value is more than upper limit threshold and is masked as 1, is set low when less than lower threshold It is otherwise 0 that lower limit is masked as 1；

As the continuous N of super upper limit mark_overIt is secondary to reduce one gear of yield value when being all 1, as the continuous N of low limit mark_sag It is secondary when being all 1, increase one gear of yield value.

It is described search in continuous N number of ADC quantized values maximum and minima the step of in, the input voltage of the ADC Scope is designated as V_min～V_max, when input voltage is less than or equal to V_minWhen ADC output minimum range quantized value Q_min, when input voltage it is big In equal to V_maxWhen ADC output full scale quantized value Q_max, when input voltage is in range ability, output quantization value Q is with input electricity Pressure V linear changes.

The bit wide of the quantized value Q of the ADC is 8～14 bits.

It is described calculate the less difference relative to 50% full scale quantized value relative value the step of described in Relative value R_nComputing formula be：

Wherein Q_half=(Q_max-Q_min)/2, d_min,nFor less one in 2 differences described in step S203, sequence number n table Show that n-th searches maximin.

It is described that the super upper limit is put when the relative value is more than upper limit threshold to be masked as 1 to be otherwise 0, when less than lower threshold Set low lower limit be masked as 1 otherwise be 0 degree the step of in, the upper limit threshold is more than 2 times of the lower threshold.

It is described to work as the continuous N of super upper limit mark_overIt is secondary to reduce one gear of yield value when being all 1, when low limit mark it is continuous N_sagIt is secondary when being all 1, the step of increase one gear of yield value in, when arbitrarily once the super upper limit is masked as 0 or has carried out once Reduce the operation of yield value, super upper limit Blip Counting device resets, when arbitrarily once low limit is masked as 0 or is once increased Plus the operation of yield value, low limit Blip Counting device clearing.

It is described reduction one gear of yield value represent ADC input signals are contracted to it is originalThe increase gain One gear of value represent ADC input signals are amplified to it is originalTimes；

The yield value determined by the control word of 4 bits, increase by one gear of yield value will control word add 1, subtract Few one gear of yield value will control word subtract 1, be not further added by when control word increases to maximum permissible value, when control word is reduced to most No longer reduce during little permissible value；

The control word is initialized as a particular value when automatic growth control is enabled every time, i.e., input signal is not amplified Also do not reduce.

A kind of power carrier communication system automatic gain control equipment, including such as lower module：

Maximin searching modul, for searching maximum and minima in continuous N number of ADC quantized values；

Difference calculating module, for calculate the difference and the minima of the maximum and full scale quantized value with most The difference of small-range quantized value；

Difference comparsion module, for calculating less one in 2 differences；

Range computing module, for assessing the amplitude size of ADC input signals, that is to say a calculating less difference It is worth the relative value relative to 50% full scale quantized value；

Whether range judges indicating module, for judging and indicating input signal in desired range of signal；

Gain regulation module, for calculating simultaneously output gain control word, determines the input signal of ADC is amplified or contracted It is little.

The existing technology of present invention contrast has the advantages that：

Carrier signal not only can be zoomed to a suitable intensity when power line channel is preferable by the present invention, in low noise Than in the case of, there is very strong immunocompetence to impulsive noise, can effectively prevent the mistake adjustment of gain.

On the other hand, the present invention only calculates the maximum and minima of sampled signal when docking receipts signal amplitude judges, Without multiplying, calculating is simply easily achieved.

Description of the drawings

Fig. 1 is the connection diagram of a kind of automatic gain control equipment provided in an embodiment of the present invention and other devices；

Fig. 2 is a kind of auto gain control method schematic flow sheet provided in an embodiment of the present invention；

Fig. 3 is a kind of automatic gain control equipment schematic diagram provided in an embodiment of the present invention.

Specific embodiment

In order that advantages of the present invention and technical scheme are easier to understand, with reference to the accompanying drawing in the present embodiment, to this Technical scheme in inventive embodiments is described in further detail.

As shown in figure 1, power line communication receiving unit module passes through automatic growth control (Automatic Gain Control, AGC) adjustment programmable gain amplifier (programmable gain amplifier, PGA) amplification, Docking is received carrier signal and is suitably zoomed in or out, to ensure ADC sampled signals precision enough and will not occur for a long time Amplitude saturation.

As shown in Fig. 2 a kind of power carrier communication system auto gain control method, comprises the following steps：

Step S201：Search the maximum Q in continuous N number of ADC quantized values_max,nWith minima Q_min,n, be formulated as Under：

Q_max,n=max { Q_i,Q_i+1,……,Q_i+N-1}

Q_min,n=min { Q_i,Q_i+1,……,Q_i+N-1}

Wherein i=nN, n=0,1,2 ... ..., sequence number n represents that n-th searches maximin, and max { A } is represented and searched The maximum of array A, min { A } represent the minima for searching array A；

In one embodiment of the invention, N values are 64；

The input voltage range of the ADC is designated as V_min～V_max, wherein V_maxMore than V_min, when input voltage is less than or equal to V_minWhen ADC output minimum range quantized value Q_min, when input voltage is more than or equal to V_maxWhen ADC output full scale quantized value Q_max, When input voltage is in range ability, output quantization value Q is with input voltage V linear changes；

The bit wide of the quantized value Q of the ADC is 8～14 bits；

In one embodiment of the invention, the bit wide of the quantized value Q be 10 bits, the minimum range quantized value Q_min0 is taken as, the full scale quantized value Q_maxIt is taken as 1023；

In one embodiment of the invention, it is the maximum dynamic range that obtains the ADC input end signals, it is defeated in ADC Entering end increases a DC offset voltage V_halfSo that when no AC signal is input into, ADC exports 50% full scale and quantifies Value, when there is AC signal to be input into, the quantized value of ADC outputs is fluctuated up and down in 50% full scale quantized value.

Step S202：Calculate the maximum Q_max,nWith full scale quantized value Q_maxDifference d_1,nAnd the minima Q_min,nWith minimum range quantized value Q_minDifference d_2,n, computing formula is as follows：

d_1,n=Q_max-Q_max,n

d_2,n=Q_min,n-Q_min

Step S203：Calculate less one in 2 differences, be designated as d_min,n, it is formulated as follows：

d_min,n=min { d_1,n,d_2,n}

Step S204：A less difference is calculated relative to 50% full scale quantized value Q_halfRelative value R_n, meter Calculating formula is：

Wherein Q_half=(Q_max-Q_min)/2；

In one embodiment of the invention, Q_halValue after f rounds up is 512；

In one embodiment of the invention, relative value R_nSpan be 0～1, relative value R_nSize reflect The excursion of ADC input AC signals, its value show that more greatly the excursion (peak-to-peak value) of AC signal is bigger.

Step S205：As the relative value R_nMore than upper limit threshold R_overWhen put the super upper limit and be masked as 1 otherwise for 0, when relative Value R_nLess than lower threshold R_sagWhen set low lower limit be masked as 1 otherwise be 0；

The upper limit threshold R_overIt is the lower threshold R_sagMore than 2 times；

In one embodiment of the invention, upper limit threshold R_overFor 0.75, lower threshold R_sagFor 0.1875, it is ensured that Signal is after zooming in or out in the range of threshold value restriction.

Step S206：As the continuous N of super upper limit mark_overIt is secondary to reduce one gear of yield value when being all 1, when low limit mark The continuous N of will_sagIt is secondary when being all 1, increase one gear of yield value, when arbitrarily once the super upper limit is masked as 0 or is once subtracted The operation of little yield value, super upper limit Blip Counting device reset, when arbitrarily once low limit is masked as 0 or is once increased The operation of yield value, low limit Blip Counting device reset；

It is described reduction one gear of yield value represent ADC input signals are contracted to it is originalThe increase gain One gear of value represent ADC input signals are amplified to it is originalTimes；

The yield value determined by the control word of 4 bits, increase by one gear of yield value will control word add 1, subtract Few one gear of yield value will control word subtract 1, be not further added by when control word increases to maximum permissible value, when control word is reduced to most No longer reduce during little permissible value；

The control word inputs to PGA, and PGA arranges amplification according to the value of control word；

The control word is initialized as a particular value when automatic growth control is enabled every time, i.e., input signal is not amplified Also do not reduce；

In one embodiment of the invention, the control word maximum permissible value is 15, the control word minimum permissible value For 0, the dynamic range of such automatic gain is up to 45dB；

In one embodiment of the invention, the control word initialization value is 0；

In one embodiment of the invention, described zoom in or out ADC input signals is referred to the friendship of ADC inputs Stream signal is zoomed in or out, and the DC offset voltage of ADC inputs keeps constant；

Control parameter N_overAnd N_sagBigger, automatic growth control is more insensitive to high power pulse interference in short-term, to carrying The time that the adjustment of ripple signal amplitude needs is longer；

In one embodiment of the invention, control parameter N_overValue is 8, control parameter N_sagValue is 8.

It is corresponding with a kind of power carrier communication system auto gain control method embodiment that the present invention is provided, the present invention A kind of power carrier communication system automatic gain control equipment is also provided.

As shown in figure 3, a kind of power carrier communication system automatic gain control equipment, including such as lower module：

Maximin searching modul 301, for searching maximum and minima in continuous N number of ADC quantized values；

Difference calculating module 302, for calculating the difference and the minima of the maximum and full scale quantized value With the difference of minimum range quantized value；

Difference comparsion module 303, for calculating less one in 2 differences；

Range computing module 304, for assessing the amplitude size of ADC input signals, that is to say calculating described less one Relative value of the individual difference relative to 50% full scale quantized value；

Whether range judges indicating module 305, for judging and indicating input signal in desired range of signal；

Gain regulation module 306, for calculating simultaneously output gain control word, determines it is to amplify also to the input signal of ADC It is to reduce；

The above is only a kind of specific embodiment of the present invention, it is therefore an objective to made skilled artisan understands that and realizing The present invention, it is impossible to assert that the specific embodiment of the present invention is limited only to these explanations, in the situation without departing from spirit of the present invention Under, specific embodiment can have variations and modifications, and these change and modifications the scope for still falling within that the present invention is covered.

Claims (10)

1. a kind of power carrier communication system auto gain control method, it is characterised in that comprise the following steps：

Search the maximum and minima in continuous N number of ADC quantized values；

Calculate the difference of difference and the minima of the maximum with full scale quantized value and minimum range quantized value；

Calculate less one in 2 differences；

Calculate relative value of the less difference relative to 50% full scale quantized value；

It is otherwise 0 the super upper limit to be put when the relative value is more than upper limit threshold and is masked as 1, when less than lower threshold sets low lower limit It is otherwise 0 to be masked as 1；

As the continuous N of super upper limit mark_overIt is secondary to reduce one gear of yield value when being all 1, as the continuous N of low limit mark_sagIt is secondary to be all When 1, increase one gear of yield value.

2. auto gain control method according to claim 1, it is characterised in that the continuous N number of ADC quantized values of the lookup In maximum and the step of minima in, the input voltage range of the ADC is designated as V_min～V_max, when input voltage less than etc. In V_minWhen ADC output minimum range quantized value Q_min, when input voltage is more than or equal to V_maxWhen ADC output full scale quantized value Q_max, when input voltage is in range ability, output quantization value Q is with input voltage V linear changes.

3. auto gain control method according to claim 2, it is characterised in that the position of the quantized value Q of the ADC A width of 8～14 bit.

4. auto gain control method according to claim 1, it is characterised in that a calculating less difference Relative value R described in the step of being worth the relative value relative to 50% full scale quantized value_nComputing formula be：

$R_n=\frac{Q_{half}-d_{min,n}}{Q_{half}}$

Wherein Q_half=(Q_max-Q_min)/2, d_min,nFor less one in 2 differences described in step S203, sequence number n represents N lookup maximin.

5. auto gain control method according to claim 1, it is characterised in that described when the relative value is more than the upper limit The super upper limit is put during threshold value and 1 is masked as otherwise for 0, the step of lower limit is set low when less than lower threshold being masked as 1 and be otherwise 0 degree In, the upper limit threshold is more than 2 times of the lower threshold.

6. auto gain control method according to claim 1, it is characterised in that described as the continuous N of super upper limit mark_over It is secondary to reduce one gear of yield value when being all 1, as the continuous N of low limit mark_sagIt is secondary when being all 1, increase one gear of yield value The step of in, when arbitrarily once the super upper limit be masked as 0 or carried out once reduce yield value operation, super upper limit Blip Counting Device resets, when arbitrarily once low limit is masked as 0 or has carried out once increasing the operation of yield value, low limit Blip Counting device Reset.

7. auto gain control method according to claim 6, it is characterised in that one gear table of the reduction yield value Show and be contracted to ADC input signals originalDescribed increase one gear of yield value is represented and is amplified to ADC input signals OriginallyTimes.

8. according to the arbitrary described auto gain control method of claim 1 to 7, it is characterised in that the yield value is by one 4 The control word of bit determines, increase by one gear of yield value will control word add 1, reducing one gear of yield value will control word Subtract 1, be not further added by when control word increases to maximum permissible value, no longer reduce when control word is minimized permissible value.

9. auto gain control method according to claim 8, it is characterised in that the control word enable every time it is automatic A particular value is initialized as during gain control, i.e., input signal is not amplified and is not also reduced.

10. a kind of power carrier communication system automatic gain control equipment, it is characterised in that include such as lower module：

Maximin searching modul, for searching maximum and minima in continuous N number of ADC quantized values；

Difference calculating module, for calculating the difference and the minima and minimum of the maximum and full scale quantized value The difference of journey quantized value；

Difference comparsion module, for calculating less one in 2 differences；

Range computing module, for assessing the amplitude size of ADC input signals, that is to say a calculating less difference phase For the relative value of 50% full scale quantized value；

Whether range judges indicating module, for judging and indicating input signal in desired range of signal；

Gain regulation module, for calculating simultaneously output gain control word, determines the input signal of ADC is amplified or reduced.