MXPA02006990A

MXPA02006990A - Wireless communications receiver employing quick paging channel symbols.

Info

Publication number: MXPA02006990A
Application number: MXPA02006990A
Authority: MX
Inventors: Farrokh Abrishmkar
Original assignee: Qualcomm Inc
Priority date: 2000-01-17
Filing date: 2001-01-17
Publication date: 2003-01-28
Also published as: BR0107663A; HK1051290A1; AU2793801A; CN1395806A; JP2003520539A; EP1249146A1; CN1248536C; WO2001054445A1; KR20020071950A; RU2002122085A; AU774692B2

Abstract

A system for efficiently employing a quick paging channel signal to determine the presence of a forthcoming primary paging channel in a wireless communications system employing a quick paging channel and a primary paging channel. The system includes a first mechanism for selectively processing a first quick paging channel symbol andor a second quick paging channel symbol of a received signal based on a first decision parameter andor a second decision parameter and providing a first indication in response thereto. A second mechanism processes the first quick paging channel symbol in response to the first indication and provides a second indication in response thereto indicating whether a forthcoming primary paging channel signal should be received and processed. A third mechanism processes the second quick paging channel symbol in response to the first indication and the second indication and provides a third indication in response thereto specifying whether the primary paging channel should be received an processed. In a specific embodiment, the system is adapted for use with a mobile station and further includes a fourth mechanism for selectively employing the third mechanism when the second indication does not indicate that the forthcoming primary paging channel should be received and processed. The first decision parameter CSI1 is representative of a quality of a signal environment through which the received signal propagates and is described by the equation (I) where Epilot1 represents the normalized pilot energy of a portion of the pilot signal associated with the first quick paging symbol, and io1 represents a total energy of a portion of the received signal associated with the first quick paging symbol.

Description

WIRELESS COMMUNICATIONS RECEIVER THAT USES CALL CHANNEL SYMBOLS QUICK LOCATION FIELD OF THE INVENTION This invention relates to wireless communication systems. Specifically, the present invention relates to receivers for demodulating fast location call channels in communication systems that employ more than one location call channel to facilitate off-line processing.

BACKGROUND OF THE INVENTION "Wireless communication systems are employed in a variety of demanding applications ranging from searches and rescue to Internet applications. Such applications require reliable, cost-effective and efficient space communication systems accompanied by cordless phones that have maximum battery life and associated waiting time. . Telecommunications systems cellular, such as Code Division Multiple Access (CDMA) systems, are frequently characterized by a plurality of mobile stations (e.g., cell phones, mobile units, cordless phones, or mobile phones) in communication with one or more Subsystems of Base Station Transceiver (BTS's). The signals transmitted by the mobile stations are received by a BTS and are often retransmitted to a Mobile Switching Center (MSC) having a Base Station Controller (BSC). The MSC, in turn, directs the signal to a Public Switched Telephone Network (PSTN) or another wireless telephone. Similarly, a signal can be transmitted from the PSTN to a wireless telephone through a base station or BTS and an MSC. Wireless communication networks frequently employ various channels, such as location call channels and traffic channels, as described in the telephone standard, IS-95 cell phones, to facilitate communications between a wireless telephone and a BTS. The messages of Location calls are transmitted over a location call channel by a BTS to an associated cordless telephone to indicate an incoming call. Once the wireless telephone detects a location call message, a sequence of service negotiation messages is transmitted between the wireless telephone and the associated BTS urn to establish a traffic channel. A traffic channel supports voice and data traffic. Conventionally, a wireless telephone continuously monitors the location call channel for location calls indicative of incoming calls. The cordless telephone receiver remains on as long as the signal processing circuitry within the cordless handset demodulates the paging call channel to determine if a paging call was sent. Unfortunately, the receiver draws power in excess, which significantly limits the life of the phone's battery. Systems to minimize the power consumption of cordless telephone are employed often on the cordless phone and / or companion network to extend the life of the phone's battery, that is, the waiting time. To improve standby time, some recent cordless phones operate in interval mode. In the interval mode, the wireless telephone receiver is activated periodically according to predetermined call locations, established in accordance with the IS-95 telecommunications standard. An associated BTS transmits location calls during call intervals. The waiting time of the wireless telephone is extended by increasing the receiver's periodic power and demodulating the location call channel instead of continuously demodulating the entire location call channel as was done previously. Unfortunately, location call channel messages are often long and require extensive processing, which increases the power consumption of the telephone and reduces the battery life and associated wait time. Further,CR. the design of such systems and the associated location call channels requires redundant processing of the long messages of the location call channel to detect incoming calls. This reduces the life of the phone's battery. Additional increases in telephone standby are achieved through a relatively new addition to the IS-95 telecommunications standard known as off-line processing. In a wireless communication network employing off-line processing, a pair of fast call channel symbols (QPCH) is periodically transmitted to the cordless telephone. The fast location call channel symbols, i.e. fast location calls, indicate the presence or absence of an incoming call to be established on an incoming traffic channel (F-CCCH). The symbols of QPCH arrive in pairs at 9600 bits per second (bps) or 4800 bps. The time intervals in which the QPCH symbols are transmitted are transmitted from an associated BTS are known by the cordless telephone, which increases periodically the receiver's power at corresponding time intervals. In a cordless phone that employs off-line processing, the wireless telephone receiver increases power, samples from the QPCH, immediately afterwards decreases the power of the receiver and processes the QPCH sample off-line (when the receiver is out of line ). Subsequent analysis of the QPCH sample or samples indicates whether the cordless telephone should increase the receiver's power and demodulate the call channel to receive an incoming location call associated with an incoming call. The use of the QPCH helps to minimize the activation time of the receiver and the complete demodulation instances of the location call channel, allowing a reduction in the power consumption of the cordless telephone and an extension associated with the life of the telephone battery. Unfortunately, the existing systems and methods for demodulating the QPCH and deciding whether or not to process all of the subsequent location call channel based on the QPCH are undesirably large, expensive, consume an excess of power, and are generally ineffective. In addition, existing systems often fail to effectively employ both the symbols of the QPCH and the noise power calculations of the received signal to effectively determine whether the entire input location call channel is processed. Therefore, there is a need in the art for an efficient and cost effective system to determine whether or not the entire input location call channel is processed. There is a further need for an efficient system and method that employs noise power calculations and that selectively employs either one or both symbols of each fast location call channel range, in accordance with the existing signal environment, to detect very effectively and reliably the presence of an incoming location call through minimal hardware.

BRIEF DESCRIPTION OF THE INVENTION The need in the matter is addressed by the system to effectively employ a fast location call channel signal to determine the presence of a primary input location call channel of the present invention. In the illustrative embodiment, the inventive system is adapted for use with a wireless communication system employing a fast location call channel and a primary location call channel. The system includes a first mechanism for selectively processing a first fast location call channel symbol and / or a second fast location call channel symbol of a received signal based on a first decision parameter and / or a second parameter of decision and provide a first indication in response to it. A second mechanism processes the first fast location call channel symbol in response to the first indication and provides a second indication in response thereto indicating whether a primary location input call channel signal should be received and processed. A third mechanism processes the second fast location call channel symbol in response to the first indication and to the second indication and provides a third indication in response thereto specifying whether the primary location call channel should be received and processed. In a specific embodiment, the system is adapted for use with a mobile station and further includes a fourth mechanism for selectively employing the third mechanism when the second indication does not indicate that the primary input location call channel should be received and processed. The first decision parameter. { CSI? ) is representative of a quality of a signal environment through which the received signal propagates and is described by the following equation: - 'pilnt] CSL where. Epiíotí represents the normalized pilot energy of a portion of the pilot signal associated with the first fast location call sign, and í0? represents a total energy of a portion of the received signal associated with the first symbol of the fast location call. The second decision parameter. { Di) is described by the following equation: A = 'piloi? wherein QPi is the scalar product, vector product, or a combination thereof (depending on the mode of the mobile station) of the first symbol, with a calculation of the pilot signal associated with the first symbol. A first comparison mechanism compares the first decision parameter with a cancellation threshold and indicates (via the first indication), based on the comparison, that the first fast location call channel symbol must be processed when the first parameter of decision is "greater than a predetermined cancellation threshold." The first comparison mechanism indicates, through the first indication, that the second fast-location call symbol (and not the first fast-location call sign) should be processed when the first decision parameter is less than the cancellation threshold, the second mechanism includes a second comparison mechanism to compare the second decision parameter D) with a first on-off threshold and indicating, through the second indication, that the incoming location call channel should not be received and processed for an incoming location call. Another mechanism included in the second mechanism selectively places the mobile station into an inactive state in response to the second indication. The second comparison mechanism indicates, through the second indication, that the second fast location call sign must be processed when the first indication does not indicate that the second fast location call channel should be processed immediately and when the second decision parameter is processed. is greater than the on-off threshold. The third mechanism includes a mechanism to selectively calculate the next decision parameter (D) in response to the mechanism to indicate: wherein representa 2 represents the summed noise power calculated by all the multi-path components associated with a portion of the received signal that contains the first fast-call call channel symbol; s22 represents the summed noise power associated with a portion of the received signal containing the second fast location call channel symbol; QP2 is the scalar product, vector product, or a combination thereof between the signal components of the second fast location call channel symbol and the pilot signal associated with the second fast location call channel symbol; and £ p_.iot2 represents the energy of the pilot signal associated with the second symbol of the pilot channel. The third mechanism also includes a mechanism for comparing D with a second on-off threshold, through the third indication, that the input primary location call channel must be processed when D is greater than the second power-on threshold. off, and indicate, through the third, indication that the call channel of the Primary entry location when D is approximately less than the second on-off threshold. The novel design of the present invention is facilitated by the first mechanism and the second mechanism, which strategically processes the first fast location call channel symbol and / or the second fast location call channel signal as needed, which sometimes avoids unnecessary processing of the second fast location call channel symbol, is still provided for a maximum chance of successful detection of a fast location call channel. Additional reliability is obtained by selectively employing noise power calculations associated with the first and second fast location call channel symbols to calculate an optimal metric decision to determine when a primary input location call is processed.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a diagram of a exemplary wireless communication system constructed in accordance with the teachings of the present invention. Figure 2 is a more detailed diagram of the mobile station of Figure 1 showing a single-track rapid call (QPCH) combiner and QPCH detector built in accordance with the teachings of the present invention. Figure 3 is a flow diagram of a method implemented by the mobile station of Figure 2 through the QPCH combiner and QPCH detector of Figure 2.

DETAILED DESCRIPTION OF THE INVENTION Although the present invention is described herein with reference to illustrative embodiments for particular applications, it should be understood that the invention is not limited thereto. Those persons who have ordinary experience in the subject and access to the teachings provided herein will recognize modifications, applications and additional modalities within the scope thereof and The additional fields in which the present invention will be of signifi cant utility. Figure 1 is a diagram of a wireless communication system-10 by way of example for which the present invention is adapted. System 10 includes a Mobile Switching Center (MSC) 12 having a Base Station Controller (BSC) 14. A Public Switched Telephone Network (PSTN) 16 routes calls from telephone lines and other communications networks and devices ( not shown) to and from the MSC 12. The MSC 12 routes calls from the PSTN 16 to and from a first BTS 18 and a second BTS 20 associated with a first cell 22 and a second cell 24, respectively. The BTS's 18 and 20 are often called cell controllers. The MSC 12 routes calls between the BTSs 18 and 20. The first BTS 18 directs the calls to the first mobile station 26 within the first cell 22 through a first communications link 28. The communications link 28 is a link two way it has a forward link 30 and a reverse link 32. Typically, when the BTS 18 has established voice communications with the mobile station 26, the link 28 is characterized as a traffic channel. Although only two BTSs 18 and 20 are shown in Figure 1, more BTS's or less BTS's may be employed without being isolated from the scope of the present invention. When the mobile station 26 moves from the first cell 22 to the second cell 24, the mobile station 26 is transferred to the BTS 20. The transfer occurs "typically in an overlap region 36 where the first cell 22 overlaps the the second cell 24. in a soft handoff, the mobile station 26 establishes a second communication link 34 with the target BTS 20 in addition to the first communication link 28 with the source BTS 18. During a soft handoff, both the first link 28 and the second link 34 is maintained simultaneously.After the mobile station 26 has crossed into the second cell 24, the first communication link 28 may fall down. In a hard transfer, the communication link 34 is not established.

When the mobile station 26 moves from the first cell 22 to the second cell 24, the link 28 drops to the source BTS 18 and a new link is formed with the target BTS 20. Figure 2 is a more detailed diagram of the wireless telephone , i.e., the mobile station 26 of Figure 1 which shows a Fast Location Call Channel (QPCH) combiner (demodulation symbol computer (D)) 40 and the QPCH detector 42 constructed in accordance with. the teachings of the present invention. For the sake of clarity, various components of Figure 2 are omitted, such as Intermediate Frequency (IF) to baseband converters, mixers, subverters, timer oscillators, power supplies, and amplifiers, however those skilled in the art They will know where and how to implement the additional requirement components. The mobile station 26 includes a transceiver 44 having an antenna 46 which is connected to a duplexer 48. The duplexer 48 is connected to an input of a CDMA receiver section 50 and to an output of a transmitter of CDMA 52. A baseband processor 54 is connected to the CDMA transceiver 44 and includes a noise calculator 38, a controller 56, a random Random Access Memory (RAM) 58, an interpolator 60, a finder 62, a calculator received energy 64, a grouping / discovered circuit 66, a Pilot Calculator (pilot filter) 68, a pilot energy calculation circuit 70, a demodulator 72, the QPCH combiner 40, a QPC location call detector 42 , a Viterbi decoder 74, the memory of QPCH 80, and an encoder 76. The controller 56 is connected to a bus 78 that provides control input to the CDMA transmitter 52 and the CDMA receiver 50. An output of the CDMA receiver 50 is a digital reception signal that is provided as an input to the sample RAM 58 of the baseband processor 54. An output of the sample RAM 58 is the input to the interpolator 60. An output of the interpolator 60 is connected to the inputs of the searcher 62, and the circuit to grouper / discovered 66. An output of the finder 62 represents the peaks corresponding to candidate pilot signals, which are the input to the controller software / circuitry (a) 56. A pilot output of the array / discovered circuit 66 represents a calculation (s) of pilot signal having the signal components k in phase. { Ipiio tk) and square. { Qpxiotk) i a component Ip? Iotk And Qpíio tk for each k ^ 1 ™ 0 multipath signal component. The pilot output of the grouping / discovered circuit 66 provides input to the pilot calculator (pilot filter) 68 and the noise calculator 38. An output of the rough estimator 38 is the input to the QPCH combiner 40 and represents the k? S calculations noise-path power associated with the corresponding first or second QPCH symbols, which are represented by the symbols s2? k and o22k associated with the first symbol of QPCH and the second QPCH symbol of in interval, respectively, for k multi-path QPCH signal components detected. The output of the pilot computer 68 represents a filtered pilot value (s) and is the input to the demodulator 72 and the circuit pilot power calculation 70. An output of the pilot power calculation circuit 70 is connected to a QPCH 40 combiner input. The traffic / data channel, the primary full location call channel, and the QPCH channel outputs of the stitcher / discovered circuit 66 are the input to the demodulator 72. A scalar product, vector product, and / or scalar product output are provided. + vector product, a QPCH location call output of the demodulator 72 as input to the QPCH combiner 40. The output of the scalar product + vector product can be omitted and the sum in the QPCH combiner 40 calculated in place of the demodulator 72 without being isolated of the scope of the present invention. The traffic and primary location call channel outputs of the demodulator 72 are provided as input to the Viterbi decoder 74 after further processing through subsystems (not shown) such as scaling circuits and groupers (see IS-95 specifications). ). An output of the decoder 74 is connected to a Controller input 56. The QPCH combiner 40 communicates with the location call detector 42, an output that is connected to an input of the controller 56. A QPCH memory 80 receives inputs from the QPCH combiner 40 and the software / circuitry controller (a) 56 and provides the output to the location call detector 42. In operation, the CDMA signals received through the antenna 46 are directed to the CDMA receiver 50 through the duplexer 48. The The CDMA receiver 50 includes the conversion circuitry (not shown) of intermediate frequency radio frequency to mix the radiofrequency signals (Rx) with the intermediate frequency signals. The Automatic Gain Control (AGC) circuitry (not shown) adjusts the total power of the received signal to a predetermined value. The additional frequency conversion circuitry (not shown) mixes the intermediate frequency signals with the analog baseband signals, which are then converted to digital baseband signals through an analog-to-digital converter (not shown).

The digital baseband signals include the signal components in phase (1) / quadrature (Q) and noise. Similarly, the CDMA transmitter 52 includes the frequency conversion circuitry (not shown) for converting the digital input signals (having phase and quadrature signal components) delivered as output from the encoder 76 to the signal signals. radio frequency in preparation for transmission through the antenna 46. The sample RAM 58 in the baseband processor 54 samples the digital baseband signals received from the CDMA receiver 50 at predetermined time intervals. The sample RAM 58 keeps the samples in a buffer (not shown) for use in the off-line processing circuitry as will be described in more detail below. The predetermined time intervals in which the sample RAM 58 carries out the sampling of the. received signal are determined in accordance with IS-95 telecommunications standards. The sample RAM 58 it can be selectively bypassed when the mobile station 26 is not operating in the interval mode via an enable signal received from the controller 56. Other systems and methods for selectively bypassing the sample RAM 58 can be employed without being isolated from the scope of the present invention. The length of the signal sample taken by the sample RAM 58 is directly related to the size of the sample RAM 58. The sample RAM 48 samples the signal environment, ie, the received signal, to gather information sufficient relative to a QPCH of the received signal in order to facilitate off-line processing. An output of the sample RAM 58 is connected to the interpolator 60. The interpolator 60 overconverts a digital signal output from the sample RAM 58 to a higher digital frequency. In the present specific embodiment, the rate of the digital signal output from the sample RAM 58 is equivalent to the rate of the received digital signal, which is twice the chip rate. The interpolator 60 converts the signal rate digital to eight times the speed rate (CHIPxd). Those skilled in the art will appreciate that the exact rates of digital signals employed by the mobile station 26 are of specific application and can be determined by the person skilled in the art to meet the needs of a particular application. When the sample RAM 58 has sampled the received signal, the interpolator 60 provides an overconverted digital signal having a phase and quadrature signal component to the finder 62 and the cluster / discovered circuit 66. The finder 62 analyzes the digital signal received and delivered as output the candidate pilot peaks (one peak per each multi-path component) to the software / driver circuitry (a) 56. In one embodiment of the present invention, the search engine 62 is implemented in accordance with the teachings of the US Patent Application Serial No. 09 / 696,160, filed on October 23, 2000, by the inventor of the present invention, entitled X% EFFICIENT SYSTEM AND METHOD FOR FACILITATING QUICK PAGING CHANNEL DEMODULATION VIA AN EFFICIENT OFFLINE SEARCHER IN A IRELESS COMMUNICATION SYSTEM ", (Notary Registry No. D990319), assigned to the assignee of the present invention and incorporated herein by reference, Alternatively, searcher 62 may be implemented as a pilot grouper that may be constructed by a person skilled in the art with access to the present teachings, without isolating himself from the scope of the present invention With the predetermined knowledge of the total received signal energy as established by the AGC circuitry (not shown) in the reception chain 50 , the noise calculator 38 calculates the noise associated with the first QPCH symbol and the second QPCH symbol of a range and outputs the noise variance calculations s2ik and s22k, respectively, for each] sIt? s signal component Multiple trajectory in response to it The noise variance calculations s2? k and s22 can be calculated by methods known in the art. The pilot calculator 68 is implemented as a Response Filter of Finite Impulse (FIR) or Infinite Impulse Response Filter (IIR). The pilot calculator 68 filters the noise from the noisy pilot signal provided by the finder 62 and provides a pilot signal calculation (P) in response to it. The signal calculation Pilot P includes in-phase signal components. { Ipiio tk) and square. { Qpiio tk) associated with the kth component of the pilot multiple path signal and is represented by the next vector (P): "k = (• * p? hlk - > p? lútk) 'L 1 J A higher subscript, such as 1 or 2, is added to specify whether a given signal component corresponds to a first symbol or a second symbol, respectively, of a range of a received QPCH signal.

For example, Plk = (I p, lolu, Qplhtu) refers to the k s? Multiple path pilot calculation associated with the first QPCH symbol. A pilot signal is associated with or corresponds to a QPCH symbol when the pilot signal is received approximately simultaneously with the QPCH symbol and is provided on the same sample signal of the sample RAM 58.

The pilot signal calculation Pk is provided to the demodulator 72 and the pilot power calculation circuit 70. The pilot power calculation circuit 70 squares the calculation of the pilot signal P, and provides a calculation of the energy (Ep? lotk) of the k component of the pilot multipath signal to the combiner of QPCH 40. The pilot energy Ep iot includes a first component Epiiotik includes a first component Ep? Jotik associated with the first QPCH symbol of a QPCH interval and a second component Ep? Iot2k associated with the second QPCH symbol of the QPCH interval. The QPCH combiner 40 includes an integrator (not shown) to sum the pilot energies Epilotl and Epxlat2k over the k pilot trajectories to deliver £ p ?? ot? and Ep? lot2r respectively, according to the following equations: 'pilotl' S *. p? l ?? l2¡ [3] where Epl? 0tik is the pilot energy associated with the kth multi-signal signal component of the first QPCH symbol of a QPCH interval, and Epx? ot2kr _is the pilot energy associated with the multi-path signal component of the second symbol of QPCH of the QPCH interval. The noise variance calculations s2? K and s22k delivered as output from the noise calculator 38 are used by the QPCH combiner 40 to calculate the total noise power calculations s2? and s22 for use in the calculation of the demodulation symbol decision metric D as described in more detail below. The noise power calculations s2 ?, and s22 are described by the following equations S E pi tlk 4] E 'p "? Lot \ where the various symbols are as described previously.

The stitcher / discovered circuit 66 includes a pseudo-noise stitcher (not shown) and an uncovered M-ary Walsh circuit (not shown) to discover a pilot channel, a data channel, a primary call location channel, and a QPCH from the received signal output from the interpolator 60, if they exist in the received signal. M is 64 in the present modality. The discovered channels are provided to the demodulator 72. The demodulator 72 calculates the scalar product, vector product, or both (depending on the communication mode of the system 26 as described in more detail below) between a received QPCH signal from the grouping circuit. /discovered 66"and the pilot calculation P delivered as output by the pilot computer 68. In the present specific embodiment, the QPCH signal includes a slot having a first symbol and a second symbol defined according to the IS-telecommunications standard. 95. The scalar product (oti) of the first QPCH symbol (QPCH1) with the calculation of corresponding pilot ° 'is defined according to the following equation: - ß 1 where k is the number of multiple path components available from the received signal; Ipiio tik is the in-phase component of the pilot calculation associated with the SMO multi-path component of the first QPCH symbol of the interval; IopcHik is the in-phase component of the iésl? Non-multiple-path component of the first QPCH symbol; Qpiioti is the quadrature component of the lousy multi-path component of the pilot calculation associated with the first QPCH symbol; and QopcHi k is the quadrature component of the kés xmo multiple path component of the first QPCH symbol of the QPCH signal. Similarly, the scalar product. { t2) of the second QPCH symbol (QPCH2) with the corresponding pilot calculation Pik is defined according to the following equation: dot. = S ('. Püotl oPí H l, ^ pni? Hl »nll2k íl? I' (H 2k í l] wherein the individual symbols are similar to those previously defined for equation (6) but are associated with the second QPCH symbol of a range instead of the first QPCH symbol of the interval. Additional details of fast location call channels employed for off-line processing purposes are described in the U.S. Patent Application. Copendent Serial No. 08 / 865,650, filed May 30, 1997, by Butler et al. , entitled DUAL CHANNEL SLOTTED PAGING, (Notary Notification No. D714 PSA .7E30), assigned to the assignee of the present invention and incorporated herein by reference. Additional QPCH details are described in the U.S. Patent Application. Copendent Serial No. 09 / 252,846 filed February 19, 1999, by Agrawal et al., entitled METHOD AND APPARATUS FOR MAXIMIZING STANDBY TIME USING A QUICK PAGING CHANNEL, assigned to the assignee of the present invention and incorporated herein by reference reference. The demodulator 72 calculates the first Scalar product . { do not? ) associated with the first symbol of QPCH, the second scalar product. { do t2) associated with the second symbol of QPCH, and / or the vector products cros s? and cro s s? associated with the first and second QPCH symbols, respectively, and provides the results to the QPCH 40 combiner. The cross vector products s i and cross2 are defined according to the following equations: cross, =? . { lp? h, h QQn H - Qp? hl IQIK H [8] CrOSS 2 - 2_j And pUal 2k XÍQPt H 2k tí 'pilo! 2k * CJK H 2k j > L 9] where the individual symbols are as defined previously for equations (6) and (7). The demodulator 72 both calculates scalar products and / or products, vectors of specific application as it depends on the system mode 26. For example, in systems of 1 Multiple Carrier (IxMC) without Orthogonal Transmission Diversity (OTD) (IxMC non-OTD), the demodulator 72 calculates the scalar and vector products according to equations (4) a (9) and output as oti + cros si and do t2 + cross2 to the QPCH 40 combiner. systems of 3 Multiple Carriers (3xMC) and in systems of 1 Multiple Carrier lxMC with OTD, the demodulator 72 outputs scalar products, vector products, or sums of scalar and vector products depending on the needs of a given application. With reference to the present teachings, the output of the appropriate demodulator can be determined by the person skilled in the art to meet the needs of a particular application. The additions of the products scalar and vector (dotj + cros sx and do t2 + cross2) can be carried out in the QPCH combiner 40 without being isolated from the scope of the present invention. The output of the scrambler 72 which is taken as the input of the QPCH combiner 40 is denoted QP for the outputs associated with the first QPCH symbol of a range and QP2 for the outputs associated with the second QPCH symbol of a range. The following table summarizes various outputs of demodulator 72 for various system modes: Table 1 Alternatively, another combinational function of the pilot calculation and the first and second QPCH symbols may be provided to the QPCH combiner 40 in addition to or in place of the scalar and / or vector products, without being isolated from the scope of the present invention. The demodulator 72 may also provide a data / traffic signal, if available, to the Viterbi decoder 74 when the mobile station 26 is handling a call or other type of traffic channel. The decoder 74 can then decode the data / traffic signal, which can represent voice or any other type of data, and forward the decoded signal to the decoded signal. controller 56. Controller 56 employs various hardware and / or software modules (not shown) for addressing decoded signals to a microphone or other software or hardware function (not shown). The QPCH combiner 40 calculates a first decision parameter (CSIi), which is a proportion of carrier signal to interference, also called standardized pilot energy, and is described by the following equation: where CSIx is the normalized pilot energy associated with the first QPCH symbol of a range; Ep z _? _ Or t? is the energy of the portion of the pilot signal summed in all the multiple path components and received simultaneously with the first QPCH symbol; _? 0? is the total energy of the portion of the received signal, including noise and interference, received simultaneously with the first QPCH symbol. Similarly, the QPCH combiner 40 calculates, as required, a second decision parameter CSI2 for the second QPCH symbol of a range according to the following equation: E "CSL J üol2 [1 1] o2 where the symbols are as described above for equation (10) but are associated with the second QPCH symbol of a range. In the present specific modality, í0? and io2 are predetermined through AGC circuitry and Gain Control Amplifiers (GCA's) (not shown) in the CDMA 50 reception chain, however, ÍO1 and io2 can be calculated through energy calculators or determined through of others, mechanisms without being isolated from the scope of the present invention. A third decision parameter D is a novel decision metric representative of the value of the first QPCH symbol of the QPCH range that is described for the following equation: D, QPx [12] J pdol 1 where QPi and £ p_.iot? they are as described previously . The QPCH combiner 40 adds the parameters of CSIi and D in all available multipath components and provides the results to the location call detector 42 when requested by the location call detector 42, which behaves in accordance with a unique method of the present invention as described in more detail below. With access to the present teachings, those skilled in the art can build a QPCH combiner and a location call detector suitable for use with the present invention.The QPCH combiner 40 employs the Quick Location Call values (QP. ) QP and QP2, the pilot energy calculates Spiíotí and -Ep? Iot2 / - and the received signal energy calculations ía? And io2 associated with the first and second QPCH symbols, respectively, to calculate the demodulation symbol, ie , the decision metric D, when requested by the location call detector 42, according to the following equation: where D incorporates both the first and second symbol of the received QPCH interval and is representative of the value, either on or off, of the QPCH location call corresponding to the interval; si2 is the noise power associated with the portion of the received signal that contains the first QPCH symbol; s22 is the noise power associated with the portion of the received signal that contains the second QPCH symbol; and the remaining parameters are as previously defined. The location call detector 42 selectively compares the parameters CSI, CSI2 r D, and D with the predetermined thresholds to determine whether the mobile station 26 should subsequently increase the power of the CDMA receiver 50 to receive and process an entire location call input sent through the primary location call channel, as described in more detail below. When the location call detector 42 determines that it should be received and processing an entire input location call based on one or more comparisons of the above parameters (CSii, CSJ2, Di, and D) with predetermined thresholds, an appropriate indication is sent to the controller 56 indicating that the CDMA 50 receiver should be activated in accordance with IS-95 standards to receive and demodulate a primary location call channel immediately upon entry. The controller 56 then activates the CDMA receiver 50 and places the sample RAM 58 in standby mode by means of control signals sent through the bus 78 at a time corresponding to a time interval during which the channel is received. primary location call. The decoder 74 is automatically enabled through signaling information contained in the received signal. When the mobile station 26 receives all the location call in the primary location call channel, the location call is grouped through the grouping / uncovered circuit 66, combined with multiple path components through the demodulator 72 and is provided to it. to the decoder 74, wherein the location call is decoded. The constituent information of the location call is sent in advance from the decoder 74 to the controller 56. Software and / or hardware circuitry known in the art (not shown) within the controller 56 interprets the location call. If the location call indicates an incoming call associated with an incoming traffic channel, the controller 56 issues appropriate control commands to various modules within the mobile station 26 to prepare the mobile station 26 to handle the traffic channel of the mobile station 26. entry . If the primary location call channel should not be processed based as determined from one or more of the CSI parameters? , CS I2, D, and D, then an indication is sent to the controller 56 that specifies that an entire location call is not entering the primary location call channel. The controller 56 then subverts the transceiver section 44 and enters the mobile station 26 within a inactive state as defined in IS-95 telecommunications regulations. The QPCH is modulated in on-off switch (00K), and the Di and D values help indicate the presence or absence (on or off, respectively) of an input location call channel. Figure 3 is a flowchart of a method 100 implemented by the mobile station 26 of Figure 2 through the QPCH combiner 40, the QPCH detector 42, and the QPCH memory 80 of Figure 2. With reference to Figures 2 and 3, an initial reception step 102, a digital received signal is output as output from the interpolator 60. The received signal includes a pilot signal component and a QPCH signal component that includes a first symbol of an interval of QPCH. The pilot computer 68 outputs the components of the pilot signal, corresponding to the first QPCH symbol, from the received digital signal and provides the pilot signal components to the pilot power calculation circuit 70, which calculates and adds the pilot energies of any multiple trajectory available in accordance with equation (2) to deliver the Epiiota • L resulting pilot energy £? p? iot? is a calculation of the energy of the pilot signal associated with the first QPCH symbol. Subsequently, the control is passed to a signal quality step 104. In the signal quality step 104, an associated pilot power (CSIi) is calculated with the first QPCH symbol, which is a value representative of a quality of a portion of the received digital signal containing the first QPCH symbol. The CSI is also known as the pilot energy to received energy ratio or the carrier signal * to interference ratio and is calculated by dividing the pilot energy £ p? Iot? associated with the first symbol by the total energy of the received signal IO1 associated with the portion of the received digital signal containing the first QPCH symbol. Subsequently, the control is passed to a verification-elimination step 106. In the first verification-elimination step 106, is CSI compared? = Ep or t? / I0? with a default removal threshold Terasure that is stored in the memory of QPCH 80. Yes CSI? is less than Te z a s u r e, then the elimination is declared. When declaring the deletion for the first symbol, the signal environment through which the received signal is propagated is determined to be of insufficient quality to transmit the value of the first metric. { Di) in order to determine whether it receives and processes a primary location input call channel. In the present specific embodiment, the predetermined deletion threshold Terasure is stored in the memory QPCH 80 associated with the location call detector 42. Alternatively, the rerase threshold can be provided by the controller 56 via a bus (not shown) and will calculate dynamically in response to a changing signal environment as indicated by the pilot energy delivered as output from the pilot power calculation circuit 70._ * When the deletion is declared in the first verification step - elimination 106, the control is passed to a second symbol step 108. Otherwise, the control is passed to a first demodulation step 110. In the first demodulation step 110, the demodulator 72 calculates the fast location call symbol QP according to the table (1) and provides QPi to the QPCH combiner 40. The pilot power calculation circuit 70 provides the energy of the pilot signal (-Epioty) associated with the first QPCH symbol to the QPCH combiner 40. The QPCH combiner 40 then calculates the first Di metric according to equation (12). Subsequently, the control is passed to a noise power step 112. In the noise power step 112, the QPCH combiner 40 calculates and stores (in the memory of QPCH 80) noise calculations s? 2 for multi-path signal components available for possible post-use in order to calculate the corresponding noise power calculations si2 associated with the first QPCH symbol. Subsequently, the control is passed to a first on-off verification step 114. In the on-off verification step 114, the first decision metric Di is compared with a first on-off threshold 2i / 0. If Di is less than 2i / 0, then the control is passed to "an inactive step 116, where the transceiver 44 decreases its power and the mobile station 26 ~ is placed in an inactive state.Since the QPCH is modulated in 00K, if Di is less than Ti / or, then the portion of the QPCH interval corresponding to the first symbol has insufficient energy to be considered turned on and therefore it is considered off, which implies that the first QPCH symbol indicates that a full location call of input does not require demodulation and If Di is greater than '? i / o, then the first QPCH symbol is considered on, which implies, in accordance with the teachings of the present invention, that the second QPCH symbol of the interval must be analyzed to verify that a full-location call should be received and processed immediately upon entry into "the primary location call channel. If Di is greater than? I / o, then the control is passed to the second step of symbol 108 to verify the indicated start indication through the first QPCH and Di symbol. In the second step of symbol 108, the Steps 102, 104, and 112 are carried out "for the second QPCH symbol of the QPCH interval corresponding to the QPCH location call of the received signal to deliver values for QP2 (see table (1)) and £ p ?? 0t2 (see equation (3)) The QPCH combiner 40 then calculates CSI by dividing QP2 by £ p? Lot2-subsequently, the control is passed to a second verification-elimination step 118. In the second verification step- Withdrawal 118, CSI2 is compared with the elimination threshold Te r as ur e, which may be different from the corresponding elimination threshold in the first verification-elimination step 106 without being isolated from the scope of the present invention. that Terasure / then is considered QPCH on, and the control is passed to a primary location call step 120, where the localization call: primary input channel is received and processed in accordance with telecommunication standards IS-95. In this way, the control is passed to a second step of demodulation 122. The exact values of the various thresholds, such as the Terasure removal threshold and the on-off threshold T or with which C Ii, CSI2, and Di are compared, respectively, are of specific application and can be determined by a person skilled in the art in order to meet the needs of a given application. In the second demodulation step 122, the second QPCH symbol of the QPCH interval is processed through the QPCH combiner 40 in response to received control commands from the QPCH detector 42 to deliver the demodulation symbol D in accordance with the equations (13). The QPCH combiner 40 employs noise variance calculations delivered as output through steps 112 and 108 and equations (4) and (5) to calculate the corresponding noise power calculations employed to "calculate D according to the Equation (13) Those skilled in the art will appreciate that such control commands can be provided by the controller 56 and the QPCH combiner 40 or the controller 56 alone in place of the QPCH combiner 40 without being isolated from the scope of this invention Subsequently, the control goes to a second verification step ^ elimination 124, where D is compared to a combined on-off value TO, if it is greater than the combined on-off threshold or b / w? then the QPCH is considered turned on, and the control is passed to the primary location call step 120, where an entire incoming location call is received and processed in the primary location call channel. Otherwise, the control is passed to the idle step 116, where the mobile station 26 is placed in an inactive state. Note that the second QPCH symbol is processed similarly to the first QPCH symbol and that the pilot filter 68 in Figure 2 does not filter the QPCH symbols. By employing noise calculations to analyze the fast location call channels, the present invention allows a better diversity combination gain, which results in better overall primary location call detection performance in relation to systems and methods previous to detect incoming primary location calls. Accordingly, the present invention has been described herein with reference to a particular embodiment for a particular application. Those with ordinary experience in the subject and access to the present teachings will recognize modifications, applications, and additional modalities within the scope of the same. Therefore, it is intended that the appended claims cover any and all those applications, modifications and embodiments within the scope of the present invention.

Claims

NOVELTY OF THE INVENTION Having described the invention as an antecedent, the content of the following is claimed as property: CLAIMS 1. A system for efficiently employing a fast location call channel signal to determine the presence of a call channel signal rapid location of entry in a wireless communication system employing a fast location call channel and a primary location call channel, characterized in that it comprises: first means for selectively processing a first fast location call channel symbol and / or a second call channel symbol of fast location of a received signal based on a first decision parameter and / or a second decision parameter and to provide a first indication in response thereto; second means for processing the first fast location call channel symbol in response to the first indication and to provide a second indication in response thereto indicating whether a primary location input call channel signal should be received and processed; and third means for processing the second fast location call channel symbol in response to the first indication and the second indication and for providing a third indication in response thereto by specifying whether the primary location call channel should be received and processed.
2. The system according to the claim 1, characterized in that it further includes the fourth means for selectively employing the third means when the second indication indicates that the primary input location call channel should be received and processed.
3. The system according to the claim 2, characterized in that the system is installed in a mobile station to facilitate the successful establishment of a traffic channel between the mobile station and the wireless communication system when a location call is sent to the mobile station through the wireless communication system indicating the presence of an incoming call.
The system according to claim 2, characterized in that the first decision parameter is representative of a quality of a signal environment through which the received signal propagates.
5. The system according to claim 4, characterized in that said first decision parameter (CSIi) "is described by the following equation: -Jpdo? \ CS /, = X where Spiíotí represents the combined pilot energy of a portion of the pilot signal associated with the first fast location call sign, and i0l represents a total energy of a portion of the received signal associated with the first fast location call sign
6. The system according to claim 5, characterized in that the second decision parameter (Di) is described by the following equation: A = Q ^ J püol? wherein Q i is the scalar product, vector product, or a combination thereof of the first symbol with a calculation of the pilot signal associated with the first symbol.
7. The system according to the claim 6, characterized in that the first means further includes the means for comparing the first decision parameter with a elimination threshold and indicating through the first indication, based on the comparison and through the first indication, based on the comparison and through of the first indication, that the first fast location call channel symbol should be processed when the first decision parameter is greater than a predetermined elimination threshold.
8. The system according to the claim 7, characterized in that the first means further includes the means for indicating, through the first indication, that the second fast-location call sign should be processed immediately and not the first fast-location call symbol when the first decision parameter is less than the elimination threshold.
9. The system according to the claim 8, characterized in that said second means includes means for comparing the second decision parameter (D) with a first on-off threshold and indicating, through the second indication, that the location call channel should not be received and processed. input for an incoming location call.
10. The system according to the claim 9, characterized in that the second means further includes the means for selectively entering the system in an inactive state in response to the second indication.
11. The system according to the claim 10, characterized in that the second means includes the means for indicating, through the second indication, that the second fast location call channel symbol should be processed when the first indication does not indicate that that first call symbol should be received and processed. fast location and when the second decision parameter is greater than the on-off threshold.
12. The system according to the claim 11, characterized in that the third means includes the means for calculating the decision parameter (D) in response to the means to indicate: where Ii represents the noise power associated with a portion of the "received signal containing the first fast location call channel symbol;" s22 represents the noise power associated with a portion of the received signal that contains the second channel symbol Fast location call; QP2 is the scalar product, vector product, or a combination thereof between the signal components of the second fast location call channel symbol and the pilot signal associated with the second call channel symbol fast location, and £ p ??0t2 represents the energy of the summed pilot signal associated with a second symbol of the pilot channel associated with the second fast location call channel symbol
13. The system according to claim 12, characterized in that the third means includes further the means for comparing D with a second on-off threshold and indicating, through a third indication, that the primary input location call channel should be processed when D is greater than the second on-off threshold, and indicate, through the third indication that the primary input location call channel should not be processed when D is approximately less than the second on-off threshold.
14. A system for indicating, based on a fast location call signal associated with a fast location call channel, whether an incoming location call in a primary location call channel should be received and processed, characterized in that it comprises: first means for calculating a first parameter indicative of a quality of a signal environment in which the system is operating based on a received signal containing the fast location call signal and a pilot signal; second means for selectively processing a first symbol of the signal of fast location call in response to the first parameter and to provide a second parameter response thereto, the second parameter indicative of a signal resistance of the fast location call signal; third means for determining whether a second symbol of the fast location call channel signal is processed or a first indication that the primary location call channel for an incoming location call based on a first call is not processed decision parameter and the second decision parameter; and fourth means for selectively processing the second symbol of the fast location call channel signal in response to the third means, the fourth means including means for employing noise power calculations associated with the first fast location call symbol and the second fast location call symbol and the energies of the pilot signal and the fast location call channel signal associated with the second location call symbol fast to provide a second indication as to whether the location call channel should be processed for the call of the entry location.
15. The system according to the claim 14, characterized in that the first parameter includes a ratio of pilot signal to interference, which is the ratio of an energy of the pilot signal to the total energy of the signal of the received signal.
16. The system according to the claim 15, characterized in that the fast location call channel signal includes a range having the first fast location call channel symbol and the second fast location call channel symbol.
The system according to claim 15, characterized in that the resistance of the received signal used by the second means for determining the second parameter is a relative signal strength of the location call signal with respect to a signal strength of the signal pilot.
18. The system according to the claim 17, characterized in that the second parameter is specified through the following equation: DL- -1 pilol? where QP is a demodulation symbol that incorporates the fast location call channel signal components and the pilot signal components; and E iioti represents the energy associated with the combined pilot signal in all available multipaths and associated with the first fast location call channel symbol.
19. The system according to claim ** t 18, characterized in that the calculation of noise power includes a first calculation of noise power associated with a first call symbol of fast location of the signal of channel of call of location fast and a second calculation of noise power associated with a second fast location call symbol of the fast location channel.
The system according to claim 14, characterized in that the fifth means includes the means for comparing a decision statistic to a predetermined combined threshold and to indicate whether the entry primary quick location call channel signal channel for the location call should be processed based on the comparison.
The system according to claim 20, characterized in that said decision statistics is specified through the following equation 2 + 2 D = ^ Fpilolol ^ Fpiloto! 2 2 s, s2 where O2 is the noise power associated with a first portion of the received signal that contains the first QPCH symbol; s22 is the noise power associated with a second portion of the received signal that contains the second symbol QPCH; QPi is the scalar product, vector product, or "a combination thereof of the first QPCH symbol with a calculation of an associated portion of the pilot signal; QP is the scalar product, vector product, or a combination thereof of the second QPCH symbol with a calculation of an associated portion of the pilot signal; EP? iot? is an energy of the first portion of the signal pilot; and -? P? iot2 is an energy of the second portion of the pilot signal.
22. A system for determining, by means of a fast location call signal associated with a fast location call channel, whether an incoming location call is received and processed in a primary location call channel characterized in that it comprises: first means for receiving an electromagnetic signal and providing one or more decision parameters based on a quality of a signal environment through which the received signal propagates and / or is based on a value of a first symbol and / or a second symbol of a call channel signal component for fast location of the received signal in response to the reception of the electromagnetic signal and second means for selectively comparing the decision parameter (s) associated with a first location call channel symbol fast and / or a second location call channel symbol with one or more predetermined thresholds corresponding in response to the control signal and provide a first indication in response thereto, the first indicative indication as to whether "the incoming rapid location call channel should be received and processed."
23. A method for efficiently employing a rapid location call channel for determining the presence of a primary location input call channel signal in a wireless communication system employing a fast location call channel and a primary location call channel characterized in that it comprises the steps for: selectively processing a first fast location call channel symbol and / or a second fast location call channel symbol of a received signal based on a first decision parameter and / or a second decision parameter and provide a first indication in response to it, analyze the first symbol the fast location call channel in response to the first indication and providing a second indication in response thereto indicating whether a call-in channel should be received and processed; and processing the second fast location call channel symbol in response to the first indication and the second indication and providing a third indication in response thereto specifying whether the primary location call channel should be received and processed.
24. A system for interpreting a fast location call channel signal in a wireless communication system characterized in that it comprises: first means for analyzing a received signal and a signal environment associated with the fast location call channel to determine if they are valid one or more symbols of the received signal and provide a first indication in response thereto and second means for providing a value indicative of a message included in the quick location call channel based on the first indication and one or more symbols .
25. The system according to claim 24, characterized in that one or more symbols include a first symbol and a second symbol.
26. The system according to claim 25, characterized in that the first means includes means for analyzing the signal environment and providing a parameter indication of the signal environment through a pilot signal included in the received signal.
27. The system according to the claim 24, characterized in that it also includes the third means for indicating that the first symbol and the second symbol are unreliable based on the parameter and to selectively disable the second means in response thereto. The system according to claim 24, characterized in that the second means includes the means for selectively calculating one or more of the following metrics (Di or D): 05 + Qp? H.H; D = QP D = Jp? t \ -1 p? lot \ + J p? lot 2 where si2 is the noise power associated with a first portion of the received signal that contains the first symbol; s22 is the noise power associated with a second portion of the re-received signal containing the second symbol; QP is the scalar product, vector product, or a combination thereof of the first • symbol with a calculation of an associated portion 'of the pilot signal; Do t2 is the scalar product, vector product, or a combination thereof of the second symbol with a calculation of an associated portion of the pilot signal, £ P? i0t? it is an energy 'of the first portion of the signal piloted; and -? piiot2 is an energy _of the second portion of the pilot signal. 29. The system according to claim 28, characterized in that the second means includes means for comparing one or more metrics to one or more predetermined thresholds and providing the value in response thereto 30. A system for interpreting a channel signal rapid location call in a wireless communication system characterized in that it comprises: a receiver circuit having an antenna and a reception chain; communication with the receiver; a total energy calculation circuit received in communication with the receiver; a fast location call channel symbol combiner in communication with the pilot calculation circuit, the total received power calculation circuit, and the receiver; and a location call detector in communication with the fast location call channel symbol combiner. The system according to claim 30, characterized in that the receiver further includes a random sample access memory (RAM) connected to an output of the reception chain, an interpolator connected to an output of the sample random access memory, a grouping circuit. 32. The system according to claim 31, characterized in that the grouping circuit includes a demodulator; the sample RAM and the interpolator are included in a digital baseband processor ^ - and wherein the pilot calculation circuit includes a pilot calculation in communication with a circuit pilot energy calculation. SUMMARY A system for efficiently employing a fast location call channel signal to determine the presence of a primary location call channel in a wireless communication system employing a fast location call channel and a location call channel primary. The system includes a first mechanism for selectively processing a first fast location call channel symbol and / or a second t channel symbol called a fast location of a received signal based on a first decision parameter and / or a second decision parameter and to provide a first indication in response to it. A second mechanism processes the fast call channel symbol in response to the first indication and provides a second indication in response thereto indicating whether a signal should be received and processed. of the primary input call channel, a third mechanism processes the second fast call channel symbol in response to the ° 2 / G ^ O first indication and to the second indication and provides a third indication in response thereto specifying whether the primary location call channel should be received and processed. In a specific embodiment, the system is adapted for use with a mobile station and further includes a fourth mechanism for selectively employing the third mechanism when the second indication does not indicate that the primary location call channel must be received and processed. The first decision parameter CSI? is representative of a quality of a signal environment through which the received signal is propagated and is described by equation (I) where -Epiiati represents the normalized pilot energy of a portion of the pilot signal associated with the first call sign of fast location, et 0 l represents a total energy of a portion of the received signal associated with the first fast location call symbol. 02 ¡6 0