CN1695317A - Systems, methods of operation, and computer program products for selecting delays for PAKE receivers based on signal-to-interference ratio and/or power - Google Patents

Abstract

Delays for a RAKE receiver are selected by searching a plurality of multipaths to select a set of multi-path delays associated with the highest signal to interference ratios (SIRs) and/or power values. The respective SIR values and/or power values for the multi-path delays are averaged over a time interval and the averaged SIR values and/or power values are multiplied by a scaling factor so as to reduce the averaged SIR values and/or power values. Those multi-path delays from the set of multipath delays and a previous set of multi-path delays that have SIR values and/or power values greater than a threshold value are selected to generate a monitored set of multi-path delays. The SIR values and/or power values associated with the monitored set of multi-path delays are filtered and at least one multi-path delay from the monitored set of multi-path delays is eliminated as being correlated with another multi-path delay of the monitored set of multi-path delays to generate an output set of multi-path delays. The output set of multi-path delays are provided to a RAKE receiver.

Description

System, method of operation and computer program product for selecting delay for RAKE receiver based on signal-to-interference ratio and/or power

associated application

This application claims the benefit of US Provisional Application Serial No. 60/412899 (filed September 23, 2002), the disclosure of which is incorporated herein by reference.

Background of the invention

The present invention relates to a communication method and electronic equipment, more particularly to a spread spectrum communication method and electronic equipment.

Wireless communication systems are commonly used to provide voice and data communications to users. For example, analog cellular radiotelephone systems such as AMPS, ETACS, NMT-450 and NMT-900 have long been successfully deployed around the world. Digital cellular radiotelephone systems, such as those conforming to the North Pass standard IS-54 and the European standard GSM, have been in use since the early 1990s. A wide variety of wireless digital services collectively referred to as PCS (Personal Communication Services) have recently been introduced, including advanced digital cellular systems conforming to standards such as IS-136 and IS-95, DECT (Digital Enhanced Cordless Telephone) Low-power systems such as and data communication services such as CDPD (Cellular Digital Packet Data). Information on these and other systems can be found in "The Handbook of Mobile Communications" by Gibson, published by CRC Press.

Conventionally, a variety of access technologies are employed to provide wireless services to users of wireless systems. Traditional analog cellular systems typically employ a system called Frequency Division Multiple Access (FDMA) to create communication channels, where discrete frequency bands are used as channels for cellular terminals to communicate with cellular base stations. Typically, these frequency bands are multiplexed in geographically separated cells in order to increase system capacity.

Modern digital wireless systems typically employ different multiple access techniques such as Time Division Multiple Access (TDMA) and/or Code Division Multiple Access (CDMA) to increase spectral efficiency. In a TDMA system such as a system conforming to the GSM or IS-136 standards, a carrier is divided into sequential time slots assigned to multiple channels so that multiple channels can be multiplexed on a single carrier. CDMA systems, such as those conforming to the IS-95 standard, utilize "spread spectrum" techniques to increase channel capacity, in which the channel capacity is increased by using a unique ) modulates a data-modulated carrier signal to define a channel. Spreading codes usually consist of a series of "chips" that occur at a chip rate that is higher than the bit rate of the data being transmitted.

So-called RAKE receiver structures are usually used to recover information corresponding to one user data stream. In a typical RAKE receiver, the received composite signal is correlated with a particular spreading sequence assigned to the receiver to generate multiple time-offset correlations, each correlation corresponding to an echo of the transmitted spread signal. These correlations are then combined in a weighted manner, that is, the correlations are multiplied by weighting coefficients and then summed to obtain the decision statistics. Correlation is usually performed in multiple correlation fingers of the RAKE receiver. The outputs of all these correlated receive demodulators are combined to allow improving the overall signal-to-noise ratio of the received signal. The design and operation of a RAKE receiver is well known to those skilled in the art and therefore will not be further described herein.

In order to keep the associated receiver demodulators of a RAKE receiver synchronized with their respective channel paths, a path searcher may be employed to support the RAKE receiver. The path searcher continuously searches for new channel paths and estimates their delays. These delays are then assigned to the RAKE-related receiver demodulators. For Wideband CDMA (WCDMA) systems, detecting multipath delays is usually done as a two-stage process: In the first stage, a wide range search is performed to identify the location of the multipath delays. The resolution (ie, the interval between delays) of this first search operation is typically one chip or less. Usually, received power or Signal-to-Interference Ratio (SIR) is used as the quality standard of the delayed signal. In the second stage, a local search is performed on selected delay regions. The resolution of this second search operation is typically one-half chip to one-eighth chip. A decision is then made as to which delay to use to despread the data based on the information obtained from the local search.

Unfortunately, it may be difficult to select which local delay regions to monitor, update the monitored delays, and select the final delays for despreading data. One approach is to select the best delays (the one with the highest power and/or SIR) based on a local search, and then track the fading variation of these delays over time. The best of these delays is then used to despread the data. Unfortunately, clearly defined peaks may not be available when examining power or SIR profiles versus latency. So some complex rules may be needed to extract peaks from distributions that contain few (if any) significant peaks.

Summary of the invention

According to some embodiments of the invention, selecting delays for the RAKE receiver is accomplished by searching multiple multipaths to select a set of multipath delays associated with the highest signal-to-interference ratio (SIR) and/or power value. The SIR values and/or power values of these multipath delays are averaged at time intervals, and the average SIR value and/or power value is multiplied by a certain scaling factor, so as to reduce the average SIR value and/or power value. Those multipath delays having SIR values and/or power values greater than a certain threshold are selected from said set of multipath delays and said previous set of multipath delays to generate a monitored set of multipath delays. This choice may allow the derivation of the total delay number. filtering the SIR values and/or power values associated with the set of monitored multipath delays and removing at least one multipath delay in the set of monitored multipath delays that is associated with another one of the multipath delays , to generate a set of multipath delay outputs. The set of multipath delayed outputs is provided to a RAKE receiver.

While the method aspects of the invention have been primarily described above, it is to be understood that the invention can be implemented in the form of methods, systems and/or computer program products.

Brief introduction to the drawings

By reading the following detailed description of specific embodiments of the present invention in conjunction with the accompanying drawings, it is easy to understand other features of the present invention, in the accompanying drawings:

FIG. 1 is a block diagram showing a mobile terminal receiver according to some embodiments of the present invention;

2, 3A, 3B, 4A, 4B, and 5 are flowcharts illustrating the operation of an associated receive demodulator for selecting a delay to tune a RAKE receiver, according to some embodiments of the invention; and

6 is a timing diagram illustrating the operation of an associated receive demodulator for selecting delays to tune a RAKE receiver, according to some embodiments of the invention.

Detailed Description of the Preferred Embodiment

While the invention is capable of various modifications and takes various forms, specific embodiments are shown by way of illustration and described in detail in the drawings. It should be understood, however, that there is no intent to limit the invention to the particular forms disclosed, but on the contrary, the invention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the invention as defined by the appended claims . Like numbers refer to like parts in the description of the figures. It should also be clear that the terms "comprising" and/or "comprising" used in this specification should be understood as indicating the presence of the stated features, integers, steps, operations, units and/or components, but not excluding the presence or addition of one or multiple other features, integers, steps, components or combinations thereof.

The present invention can be implemented in the form of systems (eg, electronic devices), methods and/or computer program products. Accordingly, the present invention can be implemented in hardware and/or software (including firmware, resident software, microcode, etc.). Furthermore, the present invention can be implemented in the form of a computer program product on a computer-usable or computer-readable storage medium having embedded therein for use by or in conjunction with an instruction execution system The computer usable or computer readable program code used by the execution system. In this context, a computer-usable or computer-readable medium may be a medium that can contain, store, transmit, propagate or transport the program for use by or in conjunction with an instruction execution system, apparatus or device any medium.

A computer-usable or computer-readable medium may be, for example and without limitation, electronic, magnetic, optical, electromagnetic, infrared or semiconductor systems, devices or devices, or propagation media. More specific examples of computer readable media are as follows: electronic connection with one or more wires, portable computer disk, random access memory (RAM), read only memory (ROM), erasable programmable read only memory (EPROM) or flash memory), fiber optic cable, and compact disc read-only memory (CD-ROM). Note that a computer-usable or computer-readable medium may even be paper or another suitable medium for a printed program, since software can be captured electronically (e.g. by optical scanning of paper or other media), then compiled, interpreted Or processed in other appropriate ways when necessary, and then stored in computer memory.

This specification describes the invention in terms of selecting a delay for RAKE reception in a mobile terminal receiver. But the invention can obviously be implemented in other types of electronic equipment including RAKE receivers. Furthermore, the term "mobile terminal" as used may include cellular radiotelephones with or without multi-line display screens, Personal Communications System (PCS) terminals which may combine cellular radiotelephones with data processing, facsimile and data communication functions, may include PDAs with radiotelephones, pagers, Internet/intranet access, web browsers, organizers, calendars, and/or Global Positioning System (GPS) receivers, and conventional laptops and/or Palm receiver or other device. Mobile terminals may also be referred to as "ubiquitous computing" devices. The present invention is also described in terms of selecting delays for RAKE reception based on signal-to-interference ratio (SIR). However, it should be understood that according to some embodiments of the present invention, the power value may be used to supplement or replace the SIR value.

Referring now to FIG. 1, according to some embodiments of the present invention, a mobile terminal receiver 10 includes a path searcher module 100 configured as shown in the figure, a delay despreading and signal-to-interference ratio (SIR) calculation module 101, a delay selection and monitoring module 102 , a RAKE receiving module 103 , a channel estimation module 104 and a combining module 105 . The path search module 100 is configured to perform a wide range search to find possible multipath delays for the active channel to be demodulated. Possible multipath delays are generally characterized by high power values. Typically, the resolution of the search performed by path search module 100 is on the order of one chip. The delay despreading and SIR calculation module 101 is configured to calculate the SIR distribution of selected delays to be monitored and possible delays to be included in the SIR distribution. The resolution of the delays processed by the delay despreading and SIR calculation block 101 is generally much finer than that used by the path search block 100 . The delay selection and monitoring module 102 is configured to: control when the path search module 100 performs a new search; evaluate possible new delays obtained from the path searcher; determine when and how to update the SIR distribution of monitored delays; and It is determined which delays are to be provided to the RAKE receiver 103 for despreading the input signal containing spread spectrum data.

The RAKE receiving module 103 is configured to combine multipath signals together to take advantage of channel diversity. The receive module 103 is called a RAKE receiver because it "rakes" together the contributions of multiple multipaths. The RAKE receiving module 103 includes a plurality of processing units or RAKE related receiving demodulators. When demodulating a multipath fading channel, each associated receive demodulator of the RAKE receiver is synchronized to one of the different propagation paths of the channel. A RAKE receiver comprising L correlated receive demodulators can detect L copies of the transmitted signal, correct these signals for time delay, and then add them correlatively. The resulting signal consists of a collection of several time-delayed copies of the transmitted signal. RAKE receiver correlation receiver demodulators are usually assigned to the strongest set of multipath signals. As described above, the delay selection and monitoring module 102 determines which set of delays to use to tune the associated receive demodulator of the RAKE receiver.

Channel estimation module 104 is configured to estimate channel gain and phase to generate traffic symbols, which are then provided to combining module 105, which combines the traffic symbols to generate a despread received signal.

Although Figure 1 shows an exemplary hardware and/or software architecture that may be used to select a RAKE receiver for tuning, it is to be understood that the present invention is not limited to this configuration, but is intended to cover any configuration in which the operations described above can be achieved . It will also be appreciated that the functionality of any or all of the processing blocks in Figure 1 may also be implemented using discrete hardware components, one or more Application Specific Integrated Circuits (ASICs), or programmed digital signal processors or microprocessors.

The present invention is described hereinafter with reference to flowchart illustrations and/or block diagrams of methods, electronic devices and computer program products according to some embodiments of the invention. These flowcharts and/or block diagrams further illustrate exemplary operations of the mobile terminal structure shown in FIG. 1 . It will be understood that each block of the flowchart and/or block diagram illustrations, and combinations of blocks in the flowchart and/or block diagram illustrations, can be implemented by computer program instructions and/or hardware operations. These computer program instructions may be provided to a general-purpose computer, special-purpose computer, or other programmable data processing apparatus for manufacturing machines, so that when these instructions are executed by a computer processor or other programmable data processing apparatus, forms are used to implement these processes and /or means of the function specified in the box.

These computer program instructions can also be stored in a computer-available or computer-readable memory to control a computer or other programmable data processing device to work in a specific manner, so that storing these instructions in a computer-available or readable memory is included for products of instructions that implement the functions specified in these flowcharts and/or block diagrams.

It is also possible to load these computer program instructions into a computer or other programmable data processing device, so that a sequence of operation steps to be executed on the computer or other programmable device forms a computer-implemented process, so that in the computer or other programmable devices provide steps for implementing the functions/operations specified in these flowcharts and/or block diagrams.

Before describing an exemplary operation for selecting a delay to tune a correlated receive demodulator of a RAKE receiver according to some embodiments of the present invention, the following exemplary operation is first described: selecting a subset of multipath delays from a set of multipath delays; expanding the number of multipath delays that are candidates for monitoring; and the SIR values that reduce the selected multipath delays to correlate with each other.

Referring now to FIG. 2 , an exemplary operation for selecting a subset of multipath delays from a set of multipath delays in accordance with some embodiments of the present invention begins at block 200 in which a subset of multipath delays is selected from a set of multipath delays. A subset S _F of F multipath delays whose maximum SIR value exceeds the defined SIR value by at least 100 _τF %. If according to the judgment of block 205, these F multipath delays come from the first radio cell, then in the case where the multipath delay from the second radio cell has an SIR value exceeding at least 100τ _Cell % of the defined SIR value, in Block 210 removes from _SF the multipath delay in _SF with the lowest SIR value and replaces it with the multipath delay from the second cell with the highest SIR value. But a verification is performed to ensure that the subset S _F has at least one multipath delay from the first cell. This is done because the path from the second cell is uncorrelated with the path from the first cell, therefore, the second cell multipath can provide a valuable component when demodulating the multipath signal.

A determination is made at block 215 to determine whether all F multipath delays in S _F are from the first cell and the second cell. If so, in case the multipath delay from the third radio cell has an SIR value exceeding said defined SIR value by at least 100 _τCell %, at block 220, the _SF having the lowest SIR value is removed from _SF and replace it with the multipath delay from the third cell with the highest SIR value. But a verification is performed to ensure that the subset S _F contains at least one multipath delay from the first cell and the second cell. Those skilled in the art will understand that the above operations can also be extended to four or more cells.

Referring now to FIGS. 3A and 3B , exemplary operations for expanding the number of multipath delays that are candidates for monitoring according to some embodiments of the present invention will be described. FIG. 3A illustrates when the resolution of the SIR distribution (the set of multipath delays and SIR values provided to the RAKE receiver 103) is not significantly greater than the resolution of the path search module 100, the method used to expand the multipath delay as a monitoring candidate Number of demonstration operations. Operation begins at block 300, where multipath delays one-half chip to the left and right of existing multipath delays in set _SF are added to set _SF . If the new multipath delay does not have SIR values associated with the previous SIR distribution, these SIR values are initialized at block 305 to 100τ _{Net_1} % of the minimum SIR values of its left and right neighbors (if both exist) Or initialized to 100τ _{Net_0} % of the SIR value of the left or right neighbor if there is only one neighbor.

FIG. 3B illustrates an exemplary operation for expanding the number of multipath delays that are candidates for monitoring when the resolution of the SIR distribution is 4 times or 8 times that of the path search module 100 . In the case where the resolution of the SIR distribution is 4 times the resolution of the path search module 100, operation begins at block 310, where the existing multipaths in the distance set _SF are delayed by a left and right quarter and a half A multipath delay of one chip is added to the set _SF . If the new multipath delay does not have SIR values associated with the previous SIR distribution, these SIR values are initialized at block 315 based on scaling factors τ _{Net_0} , τ _{Net_1} , τ _{Net_2} , τ _{Net_3} as follows: The multipath delay of the slice, initialize these SIR values to 100τ _{Net_1} % of the minimum SIR value of its left and right neighbors (if both exist) or to the left or right neighbor if only one neighbor exists 100τ _{Net_0} % of the SIR value. For multipath delays one-half chip away, initialize these SIR values to 100τ _{Net_2} % of the minimum SIR values of their left and right neighbors (if both exist) or in the case of only one neighbor It is initialized as 100τ _{Net_3} % of the SIR value of the left or right neighbor.

It can be appreciated that the operations described in connection with FIGS. 3A and 3B can also be extended to more general cases according to some embodiments of the present invention.

Exemplary operations for reducing selected SIR values of interrelated multipath delays according to some embodiments of the present invention will now be described with reference to FIGS. 4A and 4B . FIG. 4A illustrates exemplary operations for reducing selected SIR values of interrelated multipath delays when the resolution of the SIR distribution is not significantly greater than the resolution of the path search module 100 . Operation begins at block 400, where multipath delays in a set _SF that are correlated with each other are identified. According to some embodiments of the invention, this can be done by selecting the multipath delay with the largest SIR value, and then marking the neighbors within one-half of a chip of it with a value N. Next, select the multipath delay with the next largest SIR value not marked with N, and mark the neighbors within its half-chip range with N. This process continues until all multipath delays in the set _SF have been checked. At block 405, the N _mod delays labeled N with the largest SIR values are scaled such that their SIR values are reduced by 100τ _red % of their previous value. This can improve the performance of the RAKE receiver 103 by reducing the importance of such relevant delays, prioritizing other less relevant delays.

FIG. 4B illustrates an exemplary operation for reducing selected SIR values of interrelated multipath delays when the resolution of the SIR distribution is 4 times or 8 times the resolution of the path search module 100 . In the case where the resolution of the SIR distribution is 4 times the resolution of the path search module 100, operation begins at block 410, where multipath delays in the set S _F that are related to each other are identified, which according to some embodiments of the invention may This is done by choosing the multipath delay with the largest SIR value, and marking neighbors within a quarter of a chip of it with N ₀ and between a quarter and a half of a chip away with N ₁ neighbors between. Then, select the multipath delay that is not marked with N ₀ or N ₁ and has the next largest SIR value, and mark its quarter and half chip neighbors as above. This process continues until all multipath delays in the set _SF have been checked. At block 415, the N _mod delays that are not marked with N ₀ or N ₁ and have the largest SIR value are selected and scaled such that the SIR values of those delays marked with N ₀ are scaled down to 100τ _{red_0} % of the previous value And those delayed SIR values marked N ₁ are reduced to 100τ _{red — 1} % of the previous value.

Referring now to FIGS. 5 and 6, an exemplary operation of a correlation receive demodulator for selecting a delay to tune a RAKE receiver according to some embodiments of the present invention will be described. Operation begins at block 500, where multipath delays are obtained from path searcher 100 and a set of delays is selected for evaluation. According to some demonstrative embodiments, the path search is performed within the T _PS slot cycle as shown in Figure 6, and the N _ev delays associated with the largest SIR peak are selected. The operations of FIG. 3A or FIG. 3B are then performed to expand the number of multipath delays that are candidates for monitoring. Denote the set of multipath delays obtained after performing the operations of FIG. 3A or 3B as S _PS , and denote the multipath delays in the current SIR distribution as S _B .

At block 505, the average SIR value of the multipath delay set S _PS is calculated over the T _ev slot period. The average SIR value of the multipath delay f is given by Equation 1, where SIR _f ⁽ⁿ⁾ is the instantaneous SIR value of sample n and SIR _{filt, f} ⁽ⁿ⁾ is its corresponding value after filtering, as follows:

${\mathrm{SIR}}_{\mathrm{avg},f}=\frac{{\mathrm{SIR}}_{\mathrm{filter},f}^{\left(\mathrm{no}\right)}+\underset{k=\mathrm{no}+1}{\overset{\mathrm{no}+N_{\mathrm{ev}}}{\mathrm{\Σ}}}{\mathrm{SIR}}_f^{\left(k\right)}}{N_{\mathrm{ev}}+1}$ Equation 1

At block 510 , the estimated average SIR value is compared with the existing SIR distribution to generate a new SIR distribution at time point A shown in FIG. 6 . In some embodiments, the average SIR value obtained in block 505 is multiplied by a certain scaling factor p. This may allow giving higher priority to currently older multipath delays than newer multipath delays in the SIR distribution. If the sets S _PS and S _B contain common multipath delays, then apply the maximum SIR for these paths according to Equation 2:

${\mathrm{SIR}}_{\mathrm{filter},f}^{\left(\mathrm{no}\right)}=\max ({\mathrm{SIR}}_{\mathrm{filter},f}^{\left(\mathrm{no}\right)},{\mathrm{SIR}}_{\mathrm{avg},f})$ Equation 2

This reduces the possibility of moving out multipath delays that have been incorporated into the SIR distribution. Under the condition of N _mod =N _{mod_mon} , τ _red =τ _{red_mon} or τ _{red_0} =τ _{red_0_mon} and τ _{red_1} =τ _{red_1_mon} , the SIRs in Fig. 4A and Fig. 4B for reducing the selected mutually correlated multipath delay Value operations are applied to the union of S _PS and S _B to create a temporary distribution. The multipath delay selection operation of Figure 2 will be applied to this temporary distribution under the condition τ _F =τ _{F_mon} , τ _Cell =τ _{Cell_mon} and F = F _mon to generate a set of multipath delays for delay monitoring . Then perform the operation of FIG. 3A or FIG. 3B (using the original distribution initialization) to expand the number of multipath delays as monitoring candidates to obtain the multipath delay set S _B . The operations of blocks 500, 505 and 510 are repeated for all cells, as indicated by block 515 and the two time points marked A in FIG. 6 .

At block 520, the SIR values of the multipath delay set S _B are filtered within the T _init slot using the filter parameter α _init according to Equation 3:

${\mathrm{SIR}}_{\mathrm{filter},f}^{(\mathrm{no}+1)}={\mathrm{\α}}_{\mathrm{init}}{\mathrm{SIR}}_{\mathrm{filter},f}^{\left(\mathrm{no}\right)}+(1-{\mathrm{\α}}_{\mathrm{init}}){\mathrm{SIR}}_f^{\left(\mathrm{no}\right)}$ Equation 3

Then under the conditions of N _mod =N _{mod_RAKE} , τ _{red_0} =τ _{red_0_RAKE} and τ _{red_1} =τ _{red_1_RAKE} , the operation of Fig. 4A and Fig. 4B for reducing the SIR value of the selected mutually correlated multipath delay is applied to the multi-path Path delay set S _B to generate a temporary distribution and store it. This will change the SIR distribution such that if two delays are highly correlated, one of them is essentially discarded. Under the conditions F=F _RAKE , τ _F =τ _{F_RAKE} and τ _Cell =τ _{Cell_RAKE} , the multipath delay selection operation of FIG. 2 is applied to this temporary distribution to generate a set of correlated receive Demodulator multipath delay.

At block 525, it is determined whether there is time between the end of the T _init address interval and the path search module 100 providing the new multipath delay. These time slots are labeled T _mid in FIG. 6 . If T _mid is greater than zero slot, then at block 530, under the conditions of N _mod = N _{mod_mon} , τ _red = τ _{red_mon} or τ _{red_0} = τ _{red_0_mon} and τ _{red_1} = τ _{red_1_mon} , the Operations to reduce the SIR values of the selected interrelated multipath delays are applied to _SB to create a temporary distribution. The multipath delay selection operation of Fig. 2 is then applied to the multipath delay set S _B in this temporary distribution under the conditions of τ _F =τ _{F_mon} and τ _Cell =τ _{Cell_mon} and F = F _mon . Then execute the operation in FIG. 3A or FIG. 3B to expand the number of monitored multipath delays in the set S _B as candidates. Initialization is done using the original distribution. The operations of block 520 are then performed to filter the SIR values of the multipath delays in the set S _B using Equation 3. The end of the T _mid slot corresponds to the second instance labeled B in FIG. 6 . Under the conditions of N _mod =N _{mod_RAKE} , τ _{red_0} =τ _{red0_RAKE} and τ _{red_1} =τ _{red_1_RAKE} , the operation of Fig. 4A and Fig. 4B for reducing the SIR value of selected mutually correlated multipath delays is applied to multipath Delay the set S _B and store the result as a temporary distribution. This will change the SIR distribution such that if two delays are highly correlated, one of them will be discarded. Under the conditions F=F _RAKE , τ _F =τ _{F_RAKE} and τ _Cell =τ _{Cell_RAKE} , the multipath delay selection operation of FIG. 2 is applied to this temporary distribution to generate a set of correlated receive Demodulator multipath delay. The operations of block 530 may be repeated multiple times before returning to block 500 .

2, 3A, 3B, 4A, 4B, and 5 illustrate the structure, function, and operation of an embodiment of the hardware and/or software mobile terminal receiver 10 of FIG. 1 . As such, each block represents a module, a code segment, or a code portion, which contains one or more executable instructions for implementing the specified logical functions. It should also be noted that, in other implementations, the functions noted in the blocks may be performed out of the order noted in FIGS. 2 , 3A, 3B, 4A, 4B, and 5 . For example, two blocks shown in sequence may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved.

Table 1 below contains a list of the parameters discussed above along with exemplary ranges for each parameter and recommended values for each parameter, according to some embodiments of the invention.

Table 1 parameter scope suggested value F _mon 8-30 15 F _RAKE 5-15 10 τ _{red_RAKE} 0-0.5 25 τ _{red_mon} 0-0.5 0 τ _{red_0_RAKE} 0-0.5 0.15 τ _{red_0_mon} 0-0.5 0 τ _{red_1_RAKE} 0-0.5 0.25 τ _{red_1_mon} 0-0.5 0.1 τ _{Cell_RAKE} 0.1-1.0 0.2 τ _{Cell_mon} 0.1-1.0 0.2 τ _{F_RAKE} 0-0.2 0.05 τ _{F_mon} 0-0.2 0 N _{mod_mon} 0-F _mon F _mon N _{mod_RAKE} 0-F _RAKE F _RAKE α _init 0.5-1 0.985 N _ev 1-25 15 T _init 1-25 20 T _mid 1-25 20

Numerous changes and modifications may be made to these preferred embodiments without departing substantially from the principles of the invention. All such modifications and changes are considered to be included within the scope of the present invention as set forth in the appended claims.

Claims (35)

1. A method of selecting delays for a RAKE receiver comprising: searching multiple multipaths to select a set of multipath delays associated with the highest signal-to-interference ratio (SIR) and/or power value; averaging the SIR values and/or power values of the multipath delay over a certain time interval; selecting from the set of multipath delays and a previous set of multipath delays those multipath delays having SIR values and/or power values greater than a threshold to generate a monitored set of multipath delays; filtering SIR values and/or power values associated with the set of monitored multipath delays; removing at least one of the set of monitored multipath delays that is related to another one of the multipath delays to generate a set of multipath delay outputs; and The set of multipath delayed outputs is provided to a RAKE receiver. 2. The method according to claim 1, characterized in that the operations of searching, averaging and multiplying are performed on a plurality of different cells. 3. The method according to claim 1, characterized in that: the step of selecting those multipath delays with SIR values and/or power values greater than a threshold from said set of multipath delays and a previous set of multipath delays include: Selecting from the set of multipath delays and the previous set of multipath delays those multipath delays having SIR values and/or power values greater than the threshold, such that the selected multipath delays are compatible with a plurality of cells relevant. 4. The method of claim 1, wherein the threshold is a first threshold, and wherein the set of multipath delays and the previous set of multipath delays are selected from the set of multipath delays with those multipath delays of SIR values and/or power values such that said selected multipath delays are associated with a plurality of cells comprising: A multipath delay associated with the first cell and having an associated minimum SIR value and/or power value is replaced by a multipath delay associated with the second cell having an SIR value and/or power value greater than a second threshold. 5. The method of claim 1, further comprising: expanding said set of monitored multipath delays by adding to said set of monitored multipath delays multipath delays within one-half chip range of existing multipath delays in said set of monitored multipath delays Monitored multipath delay. 6. The method of claim 5, further comprising: While expanding, initializing SIR values and/or power values for those multipath delays added to said set of monitored multipath delays based on SIR values and/or power values associated with said previous set of multipath delays or power value. 7. The method of claim 5, further comprising: While performing the augmentation, only one of the multipath delays of the added multipath delays has The respective multipath delays of the left or right neighbor multipath delays initialize the SIR values and/or power values of those multipath delays added to the set of monitored multipath delays using a second scaling factor. 8. The method of claim 5, further comprising: While expanding, the SIR values and/or power values of those multipath delays added to the set of monitored multipath delays are initialized as follows: Adjacent and right-adjacent multipath delays and corresponding multipath delays within a quarter-chip range of existing said multipath delays use a first scaling factor with only The corresponding multipath delays that are left or right adjacent to the multipath delay and are within a quarter chip of the existing said multipath delay use a second scaling factor for those multipath delays that are added that have left Adjacent and right-adjacent multipath delays and corresponding multipath delays between one-quarter and one-half chip from one of the existing multipath delays use a third scaling factor, and for those added The corresponding ones of the multipath delays that have only left or right neighbor multipath delays and are between one-quarter and one-half chip from one of said multipath delays use the fourth scaling factor . 9. The method of claim 1, wherein the step of removing said at least one multipath delay from said set of monitored multipath delays comprises: reducing a SIR value and/or a power value associated with a selected multipath delay in the set of monitored multipath delays based on mutual correlation of the multipath delays in the set of monitored multipath delays; as well as Those multipath delays having SIR values and/or power values less than a threshold are removed from the set of monitored multipath delays. 10. The method of claim 1, wherein: said set of monitored multipath delays is a first set of monitored multipath delays; said threshold is a first threshold, said set of multipath delays The delay output is a first set of multipath delay outputs; and the method further includes the steps of: selecting from said set of multipath delay outputs those multipath delays having SIR values and/or power values greater than said first threshold to generate a second monitored set of multipath delays; extending said second set of monitored multipath delays by adding to said second set of monitored multipath delays multipath delays within one-half chip range of existing multipath delays in said second set of monitored multipath delays Two sets of monitored multipath delays; filtering SIR values and/or power values associated with said second set of monitored multipath delays; selecting from said second set of monitored multipath delays those multipath delays having SIR values and/or power values greater than a second threshold to generate a third monitored set of multipath delays; removing at least one of the third set of monitored multipath delays that is related to another one of the multipath delays to generate a fourth monitored set of multipath delays; selecting from said fourth set of monitored multipath delays those multipath delays having SIR values greater than said second threshold to generate a set of multipath delay outputs; and The second set of multipath delayed outputs is provided to a RAKE receiver. 11. The method of claim 1, further comprising: selecting from said set of multipath delays and said previous set of multipath delays those multipath delays having SIR values and/or power values greater than said threshold to generate said set of monitored multipath delays Previously, the average SIR value and/or power value was multiplied by a certain scaling factor in order to reduce the average SIR value and/or power value. 12. The method according to claim 1, characterized in that: from said set of multipath delays and said previous set of multipath delays, those multipath delays with SIR values and/or power values greater than said threshold are selected. The step of generating said set of monitored multipath delays comprises: determining whether the set of multipath delays and the previous set of multipath delays include any common multipath delays; and associating each of the common multipath delays with the corresponding SIR value and/or power value of the corresponding common multipath delay in the set of multipath delays and the corresponding common multipath delay in the previous set of multipath delays The largest of the associated SIR values and/or power values of the multipath delay is associated. 13. A system for selecting delays for a RAKE receiver comprising: means for: searching a plurality of multipaths to select a set of multipath delays associated with the highest signal-to-interference ratio (SIR) and/or power value; means for performing the following operations: averaging the SIR values and/or power values of the multipath delay over a certain time interval; means for: selecting from said set of multipath delays and a previous set of multipath delays those multipath delays having SIR values and/or power values greater than a threshold to generate a set of monitored multipath delays path delay; means for: filtering SIR values and/or power values associated with said set of monitored multipath delays; means for removing at least one of the set of monitored multipath delays that is related to another one of the multipath delays to generate a set of multipath delay outputs; and Means for: providing the set of multipath delayed outputs to a RAKE receiver. 14. The system of claim 13, wherein: from the set of multipath delays and the previous set of multipath delays, those multipath delays with SIR values and/or power values greater than the threshold are selected. Path delay devices include: means for: selecting from said set of multipath delays and said previous set of multipath delays those multipath delays having a SIR value and/or a power value greater than said threshold, so that said selection The multipath delay is associated with multiple cells. 15. The system of claim 13, wherein the threshold is a first threshold, and selecting from the set of multipath delays and the previous set of multipath delays has an SIR greater than the threshold The means for those multipath delays of values and/or power values such that said selected multipath delays are associated with said plurality of cells comprises: means for performing the following operations: replacing the multipath delay associated with the first cell and having an associated minimum SIR value and/or power value greater than a second threshold with a multipath delay associated with the second cell or multipath delay in power values. 16. The system of claim 13, further comprising: means for performing, by adding to said set of monitored multipath delays multipath delays within one-half chip of an existing multipath delay in said set delays to augment the set of monitored multipath delays. 17. The system of claim 16, further comprising: means for: while expanding, initializing those multipath delays added to said set of monitored multipath delays based on SIR values and/or power values associated with said previous set of multipath delays The SIR value and/or power value of the path delay. 18. The system of claim 16, further comprising: means for performing the operation of using a first scaling factor for those multipath delays of said added multipath delays having left- and right-adjacent multipath delays while performing the augmentation and for those multipath delays of said added Only the corresponding multipath delays of the left- or right-neighbor multipath delays among the multipath delays use the second scaling factor to initialize the SIR values and/or power value. 19. The system of claim 16, further comprising: means for: while augmenting, initializing SIR values and/or power values of those multipath delays added to said set of monitored multipath delays in the following manner: The corresponding ones of those multipath delays having left and right neighbor multipath delays within one quarter chip of the existing said multipath delay use a first scaling factor for said added The corresponding multipath delays of those multipath delays that have only left or right neighbor multipath delays and are within a quarter chip range of the existing said multipath delays use a second scaling factor for said added The corresponding multipath delays of those with left and right neighbor multipath delays between one-quarter and one-half chip away from one of said multipath delays use the third scale factor, and for those multipath delays added that have only left- or right-adjacent multipath delays and are between one-quarter and one-half chip from one of the existing multipath delays The corresponding multipath delay uses a fourth scaling factor. 20. The system of claim 13, wherein the means for removing said at least one multipath delay from said set of monitored multipath delays comprises: means for performing the following operations: based on the mutual correlation of the multipath delays in the set of monitored multipath delays, reducing the SIR value and/or power value; and Means for removing from said set of monitored multipath delays those multipath delays having SIR values and/or power values less than a threshold. 21. The system of claim 13, wherein: said set of monitored multipath delays is a first set of monitored multipath delays; said threshold is a first threshold, said set of multipath delays The delayed outputs are a first set of multipath delayed outputs; and the system further includes means for: means for: selecting from said set of multipath delay outputs those multipath delays having SIR values and/or power values greater than said first threshold to generate a second monitored set of multipath delays; means for performing the following operations: by adding to the second set of monitored multipath delays within a half chip range of an existing multipath delay in the second set of monitored multipath delays multipath delays to augment the second set of monitored multipath delays; means for: filtering SIR values and/or power values associated with said second set of monitored multipath delays; means for: selecting from said second set of monitored multipath delays those multipath delays whose SIR values and/or power values are greater than said second threshold to generate a third monitored set of multipath delays path delay; means for: removing at least one of said third set of monitored multipath delays that is related to another one of the multipath delays to generate a fourth monitored set of multipath delays; means for: selecting from said fourth set of monitored multipath delays those multipath delays having SIR values and/or power values greater than said second threshold to generate a set of multipath delay outputs; as well as Means for: providing the second set of multipath delayed outputs to a RAKE receiver. 22. The system of claim 13, further comprising: means for selecting those multipath delays from the set of multipath delays and the previous set of multipath delays having SIR values and/or power values greater than the threshold to generate the Before a set of monitored multipath delays, the average SIR value and/or power value is multiplied by a scaling factor in order to reduce the average SIR value and/or power value. 23. The system according to claim 13, characterized in that: it is used to select from the set of multipath delays and the previous set of multipath delays with SIR values and/or power values greater than the threshold Those means for multipath delays to generate said set of monitored multipath delays include: means for: determining whether the set of multipath delays and the previous set of multipath delays include any common multipath delays; and means for performing the following operations: associating each of the common multipath delays with the SIR value and/or power value associated with the corresponding common multipath delay in the set of multipath delays with the previous The largest of the associated SIR values and/or power values of the respective common multipath delays in a set of multipath delays is associated. 24. A computer program product for selecting a delay for a RAKE receiver, comprising: A computer-readable storage medium containing computer-readable program code; the computer-readable program code includes: computer readable program code configured to: search a plurality of multipaths to select a set of multipath delays associated with the highest signal-to-interference ratio (SIR) and/or power value; Computer readable program code configured to perform the following operations: averaging the SIR values and/or power values of the multipath delay over a certain time interval; Computer readable program code configured to: select from the set of multipath delays and a previous set of multipath delays those multipath delays having SIR values and/or power values greater than a threshold to generate a set of Monitored multipath delay; computer readable program code configured to: filter SIR values and/or power values associated with the set of monitored multipath delays; computer readable program code configured to: remove at least one of the set of monitored multipath delays that is related to another one of the multipath delays to generate a set of multipath delay outputs; and Computer readable program code configured to provide the set of multipath delayed outputs to a RAKE receiver. 25. The computer program product according to claim 24, characterized in that it is configured to select from the set of multipath delays and the previous set of multipath delays with an SIR value and/or power greater than the threshold The computer readable program code for those multipath delay values further includes: computer readable program code configured to: select from said set of multipath delays and said previous set of multipath delays those multipath delays having SIR values and/or power values greater than said threshold, so that the selected multipath delay is associated with multiple cells. 26. The computer program product of claim 24, wherein the threshold is a first threshold, and is configured to select from the set of multipath delays and the previous set of multipath delays with Those multipath delays of said first threshold SIR value and/or power value such that said selected multipath delay is associated with said plurality of cells comprising: Computer readable program code configured to perform the following operations: replacing the multipath delay associated with the first cell and having the associated minimum Multipath delay for SIR values and/or power values. 27. The computer program product of claim 24, further comprising: Computer readable program code configured to perform the following operations: by adding to the set of monitored multipath delays an existing multipath delay in the set of monitored multipath delays by one-half chip range The set of monitored multipath delays is expanded by multipath delays within . 28. The computer program product of claim 27, further comprising: Computer readable program code configured to perform the operations of: while augmenting, initializing additions to said set of monitored multipath delays based on SIR values and/or power values associated with said previous set of multipath delays SIR values and/or power values of those multipath delays in . 29. The computer program product of claim 27, further comprising: Computer readable program code configured to perform the operation of using a first scaling factor for corresponding ones of said added multipath delays having left- and right-adjacent multipath delays while augmenting Only the corresponding multipath delays of the left- or right-neighbor multipath delays of said added multipath delays use a second scaling factor to initialize those multipath delays added to said set of monitored multipath delays SIR value and/or power value. 30. The computer program product of claim 27, further comprising: Computer readable program code configured to: while augmenting, initialize SIR values and/or power values for those multipath delays added to said set of monitored multipath delays as follows: The corresponding multipath delays of the added multipath delays having left and right adjacent multipath delays within a quarter-chip range of the existing multipath delays use a first scaling factor for corresponding ones of said added multipath delays having only left or right neighbor multipath delays within a quarter-chip range of said existing multipath delays using a second scaling factor, The corresponding multipath delays of those multipath delays that have left and right neighbors and are between one-quarter and one-half chip from one of the existing multipath delays of the added multipath delays A third scaling factor is used, and only those of the added multipath delays have left or right neighbor multipath delays and are between a quarter and a half code from one of the existing said multipath delays The corresponding multipath delay between slices uses a fourth scaling factor. 31. The computer program product of claim 24, wherein the computer readable program code configured to remove the at least one multipath delay from the set of monitored multipath delays comprises: Computer readable program code configured to perform the following operations: based on the mutual correlation of the multipath delays in the set of monitored multipath delays, reducing the the SIR value and/or power value associated with the delay; and Computer readable program code configured to remove from the set of monitored multipath delays those multipath delays having SIR values and/or power values less than the threshold. 32. The computer program product of claim 24, wherein: the set of monitored multipath delays is a first set of monitored multipath delays; the threshold is a first threshold, and the set of The multipath delayed outputs are a first set of multipath delayed outputs; and the system further includes means for: Computer readable program code configured to: select from said set of multipath delay outputs those multipath delays whose SIR values and/or power values are greater than said first threshold to generate a second set of monitored multipath delay; computer readable program code configured to: add to said second set of monitored multipath delays by adding to said second set of monitored multipath delays one-half codes of existing multipath delays in said second set of monitored multipath delays expanding the second set of monitored multipath delays by slice-wide multipath delays; computer readable program code configured to: filter SIR values and/or power values associated with said second set of monitored multipath delays; Computer readable program code configured to: select from said second set of monitored multipath delays those multipath delays having SIR values and/or power values greater than a second threshold to generate a third monitored set multipath delay; computer readable program code configured to remove at least one of said third set of monitored multipath delays that is related to another one of said multipath delays to generate a fourth monitored set of multipath delays Delay; Computer readable program code configured to: select from said fourth set of monitored multipath delays those multipath delays having SIR values and/or power values greater than said second threshold to generate a set of multipath delays path delay output; and A computer readable program configured to: provide the second set of multipath delayed outputs to a RAKE receiver. 33. The computer program product of claim 24, further comprising: Computer readable program code configured to: select from among said set of multipath delays and said previous set of multipath delays those multipath delays having SIR values and/or power values greater than said threshold Before generating said set of monitored multipath delays, said averaged SIR value and/or power value is multiplied by a scaling factor in order to reduce said averaged SIR value and/or power value. 34. The computer program product according to claim 24, characterized in that it is configured to select from the set of multipath delays and the previous set of multipath delays with an SIR value and/or power Values of those multipath delays to generate the set of monitored multipath delay computer readable programs include: computer readable program code configured to: determine whether the set of multipath delays and the previous set of multipath delays include any common multipath delays; and Computer readable program code configured to perform the following operations: associating each of the common multipath delays with the SIR value and/or power value associated with the corresponding common multipath delay in the set of multipath delays is associated with the largest of the associated SIR values and/or power values of the respective common multipath delays in said previous set of multipath delays. 35. An electronic device comprising: a path searcher module configured to: search a plurality of multipaths to select a set of multipath delays associated with the highest signal-to-interference ratio (SIR) and/or power value; A delay despreading and SIR calculation module configured to perform the following operations: average the SIR values and/or power values of the multipath delay by time intervals, and multiply the average SIR value and/or power value by a certain ratio factor, to reduce the average SIR value and/or power value; A delay selection and monitoring module configured to: select from said set of multipath delays and said previous set of multipath delays those multipath delays having SIR values and/or power values greater than a certain threshold to generating a set of monitored multipath delays; filtering SIR values and/or power values associated with the set of monitored multipath delays; removing at least one of the set of monitored multipath delays associated with the a multipath delay associated with another multipath delay in the set of monitored multipath delays to generate a set of multipath delay outputs; and The RAKE receiver has a correlated receive demodulator tuned based on the set of multipath delay outputs.

Images