The incident-power control method of personal portable communication system
Technical field
(Forward Link: power control forward link) relates in particular to and uses the frame error indicating bit (Erasure Indicator Bit) that is included in the reverse speech channel frame to control the incident-power control method of the personal portable communication system that efficient that forward power makes power improves greatly to the present invention relates to adopt the forward of the personal portable communication system (Personal Communication System) of CDMA (Code Division Multiplex access) mode.
Background technology
For the emission power output that reaches suitable adjustment travelling carriage and the emission power output of base station, the necessary signal of this bottom line and the disturbing wave ratio (Signal-to Interference Ratio) of the session services that can provide convenience to the user, promptly the minimum Eb/No (every potential energy and noise density ratio) in order to keep allowing must carry out power control.So-called power control is meant the transmitting power of regulating travelling carriage and base station by suitable level, so that can keep the performance of system with Minimum Power Level, makes the user can not feel inconvenient when conversation.Power control has from base station to the forward link power control of travelling carriage with from the power of reverse link control of travelling carriage to base station.
In communication process, when travelling carriage is positioned at multipath electric wave (multipathpropagation: multipath is propagated) phenomenon, in the time of in the honeycomb forntier region of clamour or serious interference, in order to make all channels can both keep certain speech quality, need a kind of device that can adjust the base station power level, this just is called forward power control.
The purpose of forward power control is: when non-conversation or relatively close base station or multipath is directly decayed (fading) and the influence of electric wave shade phenomenon is little or when being subjected to the interference of other base stations, the power loss of travelling carriage will reduce, and for being positioned at the area that receives difficulty or place when far away, the travelling carriage that error rate is high, all travelling carriages in the honeycomb then provide supplemental capacity, so that can both receive the electric wave that intensity level approaches the regulation power level.
In the past, utilize the forward link power control of carrying out personal portable communication system from the frame error rate (frame Error Rate) of travelling carriage report.The method is: to being positioned at the area that do not produce frame error, being that the travelling carriage in the area of reception good then reduces transmitting power; Area or remote regional travelling carriage to being positioned at the reception difficulty that produces frame error then provide supplemental capacity.At this moment, travelling carriage utilizes the various critical values relevant with power control to help carry out forward control according to the system parameters from the base station emission.
The forward power control flow of prior art is illustrated in Fig. 1.If begin from base station to the control of the forward of travelling carriage, the frame that has received by the travelling carriage inspection (S1) then, confirm the frame that received whether be error frame power reference critical value (Error FramePower-reference-threshold) (S2).This confirms the result, at the frame that receives is under the situation of error frame power reference critical value, confirm to check frame whether all be 57 frames (being to be 2 (power control report frame number/2) * 5=56.5 ≈ 57 under 7 the situation in the parameter of power control report frame number) (S3), at this moment, at Insp'd frame sum is not under the situation of 57 frames, turn back to the frame examination phase of S1, then, check the state of received frame, on the contrary, add up at Insp'd frame under the situation of 57 frames, PMRM (power measurement report information) is sent to corresponding base station (S4).So the existing power and the minimum power critical value (S5) of base station contrast base station are if above-mentioned existing power less than the minimum power critical value, is then controlled forward power, so that use minimum power (S6); If above-mentioned existing power greater than the minimum power critical value, is then controlled forward power, make power reduction (S7).In addition, in the above-mentioned stage 2, if received frame is an error frame power reference critical value, then to base station transmit power report information (S8), by the existing power and the maximum power critical value (S9) of base station contrast base station.Its result if above-mentioned existing power greater than the maximum power critical value, then uses maximum power (S10), if less than the maximum power critical value, then controls forward power, makes forward power increase (S11).
But, these existing Poewr control methods, the every 1.25ms of travelling carriage carries out a power control in reverse link, in contrast to this, in forward link,, be that one-period carries out power control promptly with the transmission time that is about 2 (power control report frame number/2) * 5 frame numbers with a certain number of.At this moment, as power control period decision parameter,, then be about 57 frames if power control report frame number is " 7 " (now using critical value); Even convert by the time, then because every frame is 20 milliseconds, so, with 1.14 seconds be one-period, carry out power control, carry out low speed control (slow control).
More detailed situation is: from travelling carriage to the frame that base station sends, travelling carriage receives reports PMRM to base station after normal frame reaches 57, reducing base station power controls, so need 1.14 seconds, and, travelling carriage is reported PMRM to base station when reaching error frame power threshold, increase base station power and control, so need the cycle of 20 milliseconds * 3=60 millisecond.At this moment because have the power control of long period time, so as shown in Figure 6, according to adjusting power significantly from the desired suitable power of base station, therefore, the emergent power waste is big, and power system capacity such as reduces at problem.
On the other hand, at United States Patent (USP) the 5th, 621, the power control techniques of open 3CDMA network in No. 723, narrated the power control techniques of cdma system for this reason, specifically, in the packet switching cdma network that the signal post of base station and travelling carriage uses, comprise following each stage: the stage of transmitting signal transport service amount from travelling carriage to base station, obtain the stage of the above-mentioned signal transport service amount that is transmitted from base station, the power control data is carried out the stage of acknowledge communication from above-mentioned travelling carriage, and in above-mentioned travelling carriage, receive and explanation power control data, finish the stage that signal transport service amount transmits.
Above-mentioned patent has been enumerated a kind of like this mode of coming power controlling with control bit, base station is estimated the power of average received in by 16 frame periods that are spaced apart, this evaluation of estimate and fixed value are compared, its comparative result, produce power control bits, with the meaning random fashion control bit is pushed to forward traffic channel (forward traffic chunnel), power is controlled.Also there is the low problem of power control efficiency in this mode.
The content of invention
The objective of the invention is in order to solve above-mentioned prior art problems.It is characterized in that providing the incident-power control method in a kind of like this personal portable communication system, it is in personal portable communication system, utilization is included in the frame error indicating bit (ErasureIndicator Bit) in the reverse speech channel frame, carry out forward power control, can control to optimum state to forward power.
For achieving the above object, the present invention takes following technical scheme:
A kind of incident-power control method of personal portable communication system, it adopts the error indication bit that is comprised from the travelling carriage of personal portable communication system in the speech channel frame that base station sends, control the forward power of personal portable information system, it is characterized in that carrying out successively following each step, the control forward power:
The information of sending at the base station receiving mobile, cycle is checked in accordance with regulations, the afore mentioned rules cycle is unit (20 milliseconds) with the frame, when judging the above-mentioned frame that has received and be erroneous frame, the frame error indication bit is set at " 1 ", when judging when being normal frame, the frame error indication bit is set at " 0 ", and the step that transmits to base station;
The 1st forward power control stage is used for when above-mentioned frame error indication bit is set at " 1 ", and the existing power and the predefined maximum power critical value of base station compared, and controls forward power according to the size of its comparative result; And
The 2nd forward power controlled step is being set at above-mentioned frame error indication bit under the situation of " 0 ", and the existing power and the predefined minimum power critical value of base station compared, and controls forward power according to the size of its comparative result.
The incident-power control method of described personal portable communication system, it is characterized in that: above-mentioned the 1st forward power controlled step, carry out forward power control during greater than above-mentioned maximum power critical value at the existing power of above-mentioned base station, use maximum power, on the existing power of above-mentioned base station makes the direction of power during less than above-mentioned maximum power critical value, increase, carry out forward power control.
The incident-power control method of described personal portable communication system is characterized in that: above-mentioned the 2nd forward power controlled step, carry out forward power control at the existing power of above-mentioned base station during less than above-mentioned minimum power critical value, to use minimum power; Carry out forward power control in the direction that makes power reduction at the existing power of above-mentioned base station during greater than above-mentioned minimum power critical value.Incident-power control method of the present invention, it is characterized in that: utilizing travelling carriage included error indicating bit in the speech channel frame of base station emission to control the method for personal portable information system forward power from personal portable communication system, carry out following phases successively, control forward power: receive from the information of base station to the travelling carriage emission, in accordance with regulations the cycle, be per 20 a milliseconds frame inspection once, if judging the above-mentioned frame that has received is the error frame, then be set at " 1 "; If be judged as normal frame, then be set at " 0 ", to the stage that base station transmits, above-mentioned frame error indicating bit is being set under the situation of " 1 ", existing power and predefined maximum power critical value to base station compare, control the 1st forward power control stage of forward power according to the size of its comparative result, and above-mentioned frame error indicating bit is being set under the situation of " 0 ", existing power and predefined minimum power critical value to base station compare, and control the 2nd forward power control stage of forward power according to the size of its comparative result.
In above-mentioned the 1st forward power control stage, it is characterized in that: forward power is controlled, so that use maximum power during greater than above-mentioned maximum power critical value at the existing power of above-mentioned base station; Increase forward power, so that increase power during less than above-mentioned maximum power critical value at the existing power of above-mentioned base station.Moreover, in above-mentioned the 2nd forward power control stage, it is characterized in that: forward power is controlled, so that use minimum power during less than above-mentioned minimum power critical value at the existing power of above-mentioned base station; Forward power is controlled, so that reduce power during greater than above-mentioned minimum power critical value at the existing power of above-mentioned base station.
Effect of the present invention:
As mentioned above, effect of the present invention is: owing to utilize the error indication bit that is comprised from the reverse speech channel frame that travelling carriage transmits to come the power of travelling carriage is controlled, so can shorten the forward power control cycle, can use power expeditiously.
Moreover, check 1 frame by 20 milliseconds cycle, forward power is controlled, then reduced power adjustment (increase and decrease) amplitude on the whole, so, the big power dissipation that causes of power adjusting range during the low speed of preventing over control.
Brief description of drawings:
Fig. 1 is the flow chart of the incident-power control method of the original personal portable communication system of expression.
Fig. 2 is the output control device flow chart that is applicable to personal portable communication system of the present invention.
Fig. 3 is the general reverse speech channel frame assumption diagram of personal portable communication system.
Fig. 4 is the frame error indicator timing diagram of Fig. 3.
Fig. 5 is the flow chart of expression personal portable communication system incident-power control method of the present invention.
The mutual comparison diagram of power efficiency when Fig. 6 is original forward power control and forward power of the present invention control.
The embodiment of invention
Below describe good embodiment of the present invention with reference to the accompanying drawings in detail.
Fig. 2 is the output control device block diagram that is suitable for personal portable communication system of the present invention, and as shown in the figure, its major part is divided into base station processing section 100 and terminating machine processing section 200 substantially.
Above-mentioned base station processing section 100 is made of following each several part: the through-put power control section 101 of control forward power, to the amplifier 102 that amplifies from the weak signal of above-mentioned terminating machine processing section 200, come signal is carried out the demodulator 103 of demodulation by this amplifier 102, signal by above-mentioned demodulator 103 is carried out the deinterleaver and the decoder (deinterleaver and decoder) 104 of deinterleave and decoding, decide the error rate deciding section 105 of error rate according to the output signal of above-mentioned deinterleaver and decoder 104, be used for detecting the Eb/No sensitive document 106 of every potential energy and power noise from the output signal of above-mentioned error rate deciding section 105 and demodulator 103, be used to select the output of above-mentioned Eb/No sensitive document 106 and the selector 107 of transmission data, and the control by above-mentioned through-put power control section 101 changes the variable bit rate VBR high output amplifier 108 of transfer rate of the output signal of above-mentioned selector 107.
Moreover above-mentioned terminating machine processing section 200 is made of following each several part: the AGC amplifier 201 that the gain of the signal that sends from base station is controlled automatically, the signal that has passed through above-mentioned AGC amplifier 201 is carried out the demodulator 202 of demodulation, the adder 203 that the output signal of the output signal of above-mentioned demodulator 202 and above-mentioned AGC amplifier 201 is carried out addition, to carry out the deinterleaver and the decoder 204 of deinterleave and decoding by the signal of above-mentioned demodulator 202, decide the error rate deciding section 205 of error rate according to the output signal of above-mentioned deinterleaver and decoder 204, utilize the output signal of above-mentioned error rate deciding section 205 to come the emission data processing section 206 that the data that are about to transmission are handled, and the go forward side by side variable bit rate VBR high output amplifier 207 of line output of the output signal of the utilizing above-mentioned adder 203 emission data power that changes from above-mentioned emission data processing section 206 output.
The output control device of the CDMA personal portable communication system suitable of the present invention of this structure of reference utilizes Fig. 2 to Fig. 6 to describe 1 embodiment of the incident-power control method of good embodiment of the present invention in detail.
Fig. 3 is illustrated in the reverse speech channel frame structure that adopts in the PCS Personal Communications System, by using 13 kilobits/second vocoders, can use the speech channel frame with 14.4 kilobits/second-1.8 kilobits/second speed between travelling carriage and base station.This frame structure is: frame error indicating bit (E) is arranged in addition, and as following detailed description, the state of the frame that before base station was reported in for 2 stages, receives.
E is frame error indicating bit (Erasure Indicator Bit: wipe indicating bit) in Fig. 3; F is that expression utilizes CRC (Cyclic Redundancy Check; The redundant code verification mode) checks the frame quality indicator (Frame QuatityIndicator) of the quality of the information bit that the frame quality is used; T is encoder tail position (Encoder Tail Bit).
Adopt a kind of like this mode in the present invention, promptly utilize above-mentioned error indicating bit (E) to accelerate power control period, the frame error notification to speech channel frame itself.
The transmit timing of above-mentioned frame error indication bit as shown in Figure 4, Fig. 4 (a) is a travelling carriage received frame timing diagram, Fig. 4 (b) is the transmit frame timing diagram.
I represents the data on the random time axle in the drawings.As shown in the figure, travelling carriage is reported on the i+1 frame to base station with PMRM and receives erroneous frame, to receive erroneous frame on the i+3 frame.This is the time slot of handling for terminating machine.
This frame error indication bit is set at " 1 " when wrong judging the frame that received, is set at " 0 " being judged as just often, transmits to base station.
The base station that receives this frame partly carries out power control with the frame error indication bit at channel unit.That is to say that the past is that per 1.14 seconds (now used value) carries out a power control, change each frame now into and be per 20 milliseconds and carry out a power control.
If utilize above-mentioned principle to further describe actual forward power control process of the present invention, then as shown in Figure 5.
That is to say that travelling carriage is set at " 0 " to error indication bit (E) if the control of beginning forward power then is that unit (per 20 milliseconds) checks the information that receives from base station with the frame when normal frame, be set at " 1 " (S20) when erroneous frame.(S30) confirmed in setting to above-mentioned error indication bit, when error indication bit is " 1 ", the existing power and the predefined maximum power critical value of base station compared (S40).
Result relatively, if the existing power of above-mentioned base station is greater than predefined maximum power critical value, then use maximum power to carry out forward power control (S50), in contrast, if the existing power of above-mentioned base station, then increases power less than above-mentioned predefined maximum power critical value and carries out forward power control (S60).
On the other hand, if above-mentioned confirmed frame error indication bit (E) is " 0 ", that is to say that the frame of reception is a normal frame, then existing power and the predefined minimum power critical value to base station compares (S70).
Result relatively, if the existing power of above-mentioned base station is less than above-mentioned predefined minimum power critical value, then use minimum power, carry out power control (S80), in contrast, if the existing power of above-mentioned base station, then reduces power greater than above-mentioned predefined minimum power critical value and carries out forward power control (S90).
The present invention as mentioned above, every frame be per 20 milliseconds control a forward power, so, carry out power control with the short cycle as shown in Figure 6, therefore, frequent power control makes the desired suitable power of base station carry out the power adjustment with less amplitude, so can prevent the waste of power.
Above reference 1 embodiment of the present invention has carried out technical descriptioon to the present invention, but the present invention is not limited only to this.