JP2003518809A - Method and apparatus for appropriately selecting soft symbols - Google Patents

Abstract

SUMMARY A method for selecting a soft symbol for subsequent operation in a communication device is disclosed. In some embodiments, the signal is received at a communication device. Next, the signal is demodulated. Thereafter, intensity levels such as the signal to noise ratio Eb / Nt are determined. Based on the intensity level determined for the signal, the bit position of the signal is determined for subsequent operation. The intensity levels and bit positions are updated as appropriate with the signal over time.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD OF THE INVENTION

The present invention relates to the field of digital communications. In particular, the invention relates to apparatus and methods for selecting appropriate soft symbols for subsequent operations, such as decoding within a communication device. The present invention discloses a method of appropriately selecting soft symbols for subsequent operations in a communication device.

[0002]

[Prior art]

Wireless communication is prevalent in all forms of information-using devices, such as cell phones, networks, personal digital assistants (PDAs), digital cameras and the like. One method of wireless communication known as code division multiple access (CDMA) spread spectrum is one of the most general-purpose wireless technologies. Increased demand and limited resources have created a need to improve the reliability and performance of wireless communication devices and systems.

FIG. 1 showing the prior art shows a known base station 104, such as a cell, and a mobile station 10.
2, a mobile phone, for example, is shown. A CDMA system uses a common bandwidth for transmitting pilot and data signals 106 between base station 104 and mobile station 102 for multiple users. Therefore, the bandwidth is occupied by the combination of many signals. Further, the original signal can take multiple paths with various forms of delay and phase shift to reach the target device. Those signals that take different paths are referred to as multipath signals. Since multipath signals can vary substantially due to signal strength and other performance factors, a method is needed to accurately evaluate received signals for processing into meaningful data, such as voice data.

One known arrangement identifies only fixed bit positions or fixed bit ranges of the combined signal for subsequent decoding processing. As is often the case, the fixed bit positions of the combined signal are chosen considering the overall performance in many different signal reception scenarios.
Unfortunately, conventional configurations typically provide only nominal performance in each of a wide range of receiving scenarios. Moreover, this fixed part of the combined signal is generally identified in the hardware and software design aspects and is then programmed into the phone. Therefore, the phone may be limited to a fixed portion of the combined signal during its entire life. As a result, there is a need for a method that overcomes the limitations of the prior art of selecting fixed bit positions from a combined signal for decoding.

In summary, there is a need to improve the reliability and performance of wireless communication devices and systems. Further, a method for accurately evaluating the received signal for processing to meaningful data, for example, voice data is required. Finally, there is a need to overcome the limitations associated with selecting fixed position bits from the combined signal for decoding.

SUMMARY OF THE INVENTION The present disclosure describes methods and apparatus for improving reliability and performance of digital communication devices and systems. In particular, the present disclosure describes a method of accurately evaluating received signals for processing to meaningful data, such as voice data.
Finally, the present disclosure describes a method of overcoming the known limitations associated with selecting fixed position bits from a combined signal for subsequent operation.

[0007] In particular, one disclosed embodiment discloses a method of selecting soft symbols for subsequent operations in a communication device as appropriate. In one embodiment, the signal is received within the communication device. The signal is then demodulated. Then, the intensity level such as the signal ratio Eb / Nt with respect to noise is determined. Based on the intensity level determined for the signal, a bit position or a series of consecutive bits from the signal is determined in the last step for subsequent operation. The intensity level and position of the bits are updated accordingly for the signal over time. Eb / Nt is evaluated to be the ratio of binding energy per bit to effective noise power spectral density, as is known by those skilled in the art.

In another disclosed embodiment, the method described above is implemented in a communication device having a processor, eg, a general purpose processor, a memory, a rake receiver and a digital signal processor (DSP). In particular, the memory unit of the communication device contains data and program instructions. The program instructions, when executed via the processor, implement the aforementioned method of appropriately selecting soft symbols from the composite signal for subsequent operation within the communication device. This bit selection process has little head room. This strategy provides a higher resolution of the original surrounding area, saturating the amplitude of large signals. This process is feasible because there is no risk of erroneous decoding of signals with large amplitudes and these signals amplitudes do not require much resolution.

These and other objects and advantages mentioned in the disclosure of the present invention will be understood by those skilled in the art from the preferred embodiments detailed below, which are illustrated in the various drawings numbered. It will be revealed if you read it.

The accompanying drawings associated with this specification, together with the description of the specification, explain the principles of the disclosed parts. The drawings referred to in this description should be understood as being free of dimensions unless otherwise noted.

DETAILED DESCRIPTION OF THE INVENTION References are made in detail to preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Although the present invention is described in connection with the preferred embodiments, it should be understood that the invention is not limited to these embodiments. On the contrary, the invention covers alternatives, modifications and equivalents, which are included within the spirit and scope of the invention as defined by the appended claims. Moreover, in the following detailed description of the invention, numerous specific details are defined in order to provide a thorough understanding of the invention. However, it will be apparent to one skilled in the art that the present invention may be practiced without these specific details. In other instances, well-known techniques, procedures, components and circuits have not been described in detail so as not to unnecessarily obscure the features of the present invention.

[0012] Certain portions of the detailed description that follows, for example, processing content, refers to procedures, logic blocks, processing, and other symbolic operations on data bits within a computer or digital system memory or signals within a communication device. It is provided in the form of display. These descriptions and presentations are the means used to most effectively convey the substance of an article made by a person who is familiar with digital communication technology to a person who is familiar with other technologies. Here, it is generally assumed that procedures, logic blocks, processes, etc., are sequences of self-consistent steps or instructions that lead to a desired result. These steps are those requiring physical manipulations of physical quantities. Typically, though not necessarily, these physical operations are electrical or magnetic operations that can be stored, transmitted, combined, compared, and otherwise manipulated within a communications device or processor. Take the form of a signal. For reasons of convenience and common usage, these signals are referred to as bits, values, elements, symbols, characters, terms, numbers, etc. that are relevant to the invention.

However, all of these terms should be construed as relating to physical manipulation and quantity and are merely a convenient label for interpretation within the terms commonly used. As will be clear from the discussion below, unless otherwise stated, throughout the discussion of the present invention, "receive", "demodulate", "decide", "select"
The terms "combining,""multiplexing," etc. refer to the operation or processing of communication devices and similar electrical computing devices that manipulate and convert data. Data is typically represented as physical quantities in registers and memory of a communications device part or computer system, as well as physical quantities in communications device part, computer system memory, registers, other information storage devices, transmitters or displays. Converted to other data.

Referring to FIG. 2A, illustrated is a functional block diagram 200 of one embodiment of the present invention that performs bit selection processing performed on signals in the context of other communication operations. In this embodiment, a communication device, such as base station 104, may use pilot signals and / or
Alternatively, a signal 240, which may include a data signal, is provided. The data signal is processed by a communication device such as a mobile phone, the functioning of which is illustrated in Figure 2A.
However, the functions illustrated may be implemented by a wide variety of communication devices, including base stations, personal computers (PCs), digital cameras, and other devices that may provide wireless communication. The invention is also suitable for a wide range of products developed according to the Bluetooth standard for wireless communication.

The communication device performs a demodulation function 242 on the signal. In one embodiment,
Multiple possible multipath signals 24 if applicable in a particular application
A demodulation function is applied to each of 2a. The channel evaluation function unit 242 functionally connected to the demodulation unit 242 evaluates the strength of each of the signals, for example, the demodulated multipath signal. The channel evaluator 244 can determine a signal strength such as a signal-to-strength ratio Eb / Nt that is well known to those skilled in the art. However, the present invention is well suited to determine other types of signal strength indicators. E
b is the received energy per bit for the desired signal and Nt is the received energy per bit for the noise in the signal, in units of watt seconds.

The combining function 246 of FIG. 2A, which is functionally connected to the demodulator 242, adds the multipath signals to provide a composite signal. Although the present invention is suitable for using signals of any configuration, composite signal 246a is the complement of the 24-bit binary number in this embodiment. The combination function unit 246 may be managed by another algorithm and management system. Gibong Jeong et al., Docket No. VSLI-3509 of the Attorney, Serial Number 60 / 172,406, entitled "Method and Apparatus for Managing Fingers for Multipath Signals", entitled "Method and Apparatus for Managing Multipath Signals" Provide detailed details. This related application is generally recognized and is hereby incorporated by reference.

The preprocessing function unit 248, which is functionally connected to the coupling unit 246, performs a preprocessing function. The pre-processing function prepares the composite signal 246a for the bit selection function unit. More specifically, the preprocessing function 248 is provided in the subsequent FIG. 2C.

The preprocessing function unit 248, which is functionally connected to the combining function unit 246, performs a preprocessing function. The preprocessing function unit prepares the composite signal 246a for the bit selection function unit. Details of the pre-processing function 248 are shown below in FIG. 2C.

The bit selector 250, which is functionally connected to the preprocessor 248 and the channel evaluator 244, appropriately selects or separates an appropriate number of bits from the signal for subsequent operation. In one embodiment, the bit selector 250 selects only the 6-bit portion of the formatted composite signal for subsequent demodulation operations. This 6
The bits are commonly referred to as "soft symbols" 250a. However, the present invention is suitable for selecting any bit length portion of the signal as appropriate for the particular application. In this embodiment, for example, in the same communication device, the particular 6-bit portion of the signal selected at one time point may be different from the particular 6-bit portion of the signal selected at a different time point. Thus, the present invention provides a bit selection function as appropriate. This feature overcomes the limitations associated with the prior art of fixing soft symbols at fixed bit positions within the composite signal. FIG. 2B illustrates exemplary criteria used to determine which portion of the signal to use. The post-processing function unit 254 functionally connected to the bit selection unit 250 executes the post-processing function. The post-processing function unit 254 prepares the soft symbol signal 250a for the demodulation function. More specifically, the post-processing function unit 254 is provided inside the subsequent FIG. 2D.

The decoding function unit 256 functionally connected to the post-processing unit 254 executes a decoding function. Decode function 256 may be implemented using any of several techniques well known to those skilled in the art. One such decoder is code division multiplexing (
It is a Viterbi decoder used in the CDMA system. The present invention provides soft symbols for decoding operations, but is suitable for using soft symbols or other bit sequences for other types of operations within a communication device.

Referring to FIG. 2B, a detailed functional block diagram of a bit selection function unit or engine according to an embodiment of the present invention is illustrated. The bit selection engine 250
Many criteria are received at interface 249. These criteria are used to determine which bits of the signal are selected for subsequent processing, eg decoding. In an embodiment, the criteria include signal strength criteria 260, tentative performance 262 and performance pattern 264. Subsequent FIG. 4 provides an example of the effect these criteria have on the bit selection process. However, the present invention is suitable for using combinations of these criteria or other types of criteria. This criterion allows the desired number of bits to be appropriately selected from the signal for any one of a plurality of subsequent operations.

The interface 249 matching the appropriate value and category in the look-up table (LUT) 252 then supplies the value at the corresponding bit position to the scaling function 251. The bit position value 260 can have many different configurations depending on the application. For example, the bit position value 260 may be a scaling value. When the scaling value is multiplexed by the composite signal 248a via the scaling unit 251, the signal is multiplied by a value less than 1 in order to reduce the bit width or the bit number of the composite number, and the appropriate bit range is set. To separate. Alternatively, the bit position value 260 may be an offset value that indicates cutting off some bits from the LSB portion of the composite signal.

Although the embodiment of FIG. 2B utilizes a LUT, any type or method of correspondence data, such as flags, may be used. Moreover, the present invention is suitable for implementing a priority scheme among the multiple criteria used for the bit selection function. That is, one of the standards may be set to have a higher weight than the other standards if it is greatly affected by the signal in the subsequent operation of the decoder or the like.

Referring to FIG. 2C, a detailed functional block diagram of the preprocessing functional unit according to an embodiment of the present invention is shown. Pre-processing can have a wide range of sub-functions.
For example, in one embodiment, composite signal 246a has the following sub-functions, a
) Pass-through filter function and b) format function are processed. However, the pre-processing function 248 is configured to provide more or less sub-functions as they are suitable for a particular application. The format function in this embodiment cuts off one or more bits on the side of the least significant bit (LSB). In this embodiment, 8 bits of the LSB side of the 24-bit composite signal are cut off. Moreover, in other embodiments, no pre-processing functionality is used. Pre-processing function unit 2
48 supplies the format signal 248a.

Referring to FIG. 2D, there is shown a detailed functional block diagram of the post-processing functional unit according to an embodiment of the present invention. The post-processor can include a wide range of sub-functions.
For example, in one embodiment, the soft symbol signal 250a has the following sub-functions, a
) Pass-through filter function 276, b) format function 278, and c) fixed point to double point conversion 280 (aka deinterleaver, depuncture, delicate and roundup to 6 bit numbers) and d). z transformation (alias, delay operator) 282. The format function in the present embodiment cuts off the non-integer part of the signal and provides the total number of signals.

Although the present embodiment provides a certain amount and type of sub-functions, the post-processing function unit 25
4 can be configured to provide sub-functions of varying amounts and types, as appropriate for the particular application. Moreover, in other embodiments, no post-processing functionality is used. The post-processing function unit 250 uses the formatted soft symbol 254a.
give. This bit selection gives almost no head loop. Moreover, it saturates large signal amplitudes. The process is feasible because at large amplitudes the signals are not likely to be erroneously decoded and do not require much resolution at these signal amplitudes. This scheme provides higher resolution in the original surrounding area and saturates large signal amplitudes.

Referring to FIG. 3, there is illustrated a hardware block diagram of a communication device used for a bit selection process according to an embodiment of the present invention. The communication device 300 of FIG. 3 may be a stand-alone unit such as a mobile phone. However, it
Printers, computers, cameras, personal digital assistants (PD
It may be a component of a larger device such as A). The present invention is applicable to any device capable of processing wireless data of suitable configuration.

The communication device 300c includes a firmware / software unit 31 connected to each other.
0 and a special purpose integrated circuit (ASIC) unit 320. The ASIC unit 320 has an antenna 303, a transceiver 304, and a rake receiver 326. Antenna 303 is connected to transceiver 304, which is in turn connected to rake receiver 326. The rake receiver 326 in this embodiment has three separate fingers 1 321, finger 2 322, and finger 3 32.
3 and 3. Each finger demodulates a separately assigned multipath signal.

The firmware / software unit 310 includes a processor 314 (for example, a general-purpose processor), a memory 316, and a digital signal processor (DSP) 317, which are connected to each other via a bus 302. The data and / or program instructions are stored in memory 316 and cooperate with other configurations of communication device 300, including configurations not shown that are well known to those of ordinary skill in the art, to process processor 314 or DSP.
317. The memory 316 of the present embodiment may include a non-volatile memory such as a read only memory (ROM) and a temporary memory such as a random access memory (RAM). ROM memory can be used to store data for a permanent function of a given service module, while RAM memory is
It can be used to store data about onsite media services data. Memory 316 may include other types of storage devices that may contain data, such as hard drives, CD-ROMs or flash memory. Instead of using memory to store instructions, a state machine can be designed to execute the desired instructions.

Although the present embodiment shows three fingers, the present invention is well suited to use with any number of fingers in a rake receiver. Further, the invention may include more or less components than those shown in the communication device 300 of this embodiment. Communication device 300 can be used to implement the functional diagrams of FIGS. 2A and 2B. For example, in one embodiment, demodulation function 242 may be completed by transceiver 304 and rake receiver 326 of ASIC 320. Alternatively, the demodulation function may be accomplished by the firmware / software portion 310 of the communication device.
In another embodiment, the pre-processing function unit 248, the bit selection function unit 250, and the post-processing function unit 254 are executed via the firmware / software 310 portion of the communication device 300. However, they can also be implemented in ASIC designs.

Referring to FIG. 4, some exemplary cases of signal performance and corresponding effects on bits of a combined signal are illustrated in an embodiment of the invention. The graph 400 is first described and then the composite signal 246a is discussed.
Finally, the interaction between these two entries is explained.

The vertical axis of the graph 400 is the signal amplitude 402, and the horizontal axis is the time 404. The signal amplitude represents the ratio of signal power to signal power or noise such as Eb / Nt. Signal performance for the three cases is shown in FIG. Each case has three separate multipath signals, one for each of the three finger demodulators shown in FIG. Case 1 411 of FIG. 4 is a group of three signals, all with large amplitude 408. This represents a strong and direct path of signals from one communication device to another. In Case 2 412, all are small amplitude 41
There are three groups of signals with zeros. This indicates a weak signal or extended distance between the communication devices. Finally, Case 3 413 is a group of three signals, two of which have a large amplitude 408 and one of which is a weak signal 413a, which changes from large amplitude 408 to small amplitude over time. Demote.

Composite signal 246a is a digital binary number that represents the strength of the additional multipath signal. In this embodiment, the composite signal is composed of 24 bits. However, the signal may have any length. Maximum bit (
MSB) is located at the left end of the bit string. Conversely, the least significant bit (LSB) is located at the right end of the bit string. A decimal point is placed somewhere in the bit string to generate a real number. In Case 1 411, the large amplitude 408 and small changes in each signal over time means that most of the changes in composite signal 246a are bits close to MSB 440. Therefore, the 6-bit soft symbol 1 451 is
The change in signal strength of Case 1 411 is shown more appropriately. And the change in the signal gives a meaningful variation in the output signal, eg a word or other data. That is, a zero change in the signal is essentially equal to a single tone representing negligible data.

In Case 2 412, a small amplitude 410 and small change in each signal over time means that most changes in the composite signal are bits close to the LSB 442.
Therefore, 6-bit soft symbol 2 452 is a better indication of the change in signal amplitude for case 2 412. In Case 3 453, the large amplitude performance of the two signals means that most of the large changes in the signals are bits near the MSB 440. However, the diminished intensity of signal 413a is due to LSB4
Adjust the position of the soft symbol slightly in the direction of 42. The particular choice of bits may depend on the particular scenario, the particular signaling standard, the particular application, and the particular level of the particular simulation or analysis used to evaluate that scenario. The present invention is well suited to provide all these specific situations to provide a wide range of configurations or processes used to select some bits from a signal for subsequent processing as appropriate.

FIG. 5 is a flowchart 5000 of steps used to implement a method of selecting soft symbols for subsequent decoding operations in a communication device in accordance with one embodiment of the present invention. Flowchart 5000 may be performed on top of the functional blocks of Figures 2A and 2B and the hardware block diagram of Figure 3. Flow chart 500
The result of performing 0 is illustrated based on the exemplary signal of FIG.

Flowchart 5000 begins at step 5002. A signal is received in step 5002 of this embodiment. Step 5002 may be performed by antenna 303. Alternatively, the signal may be received by other wireless means such as a satellite dish.
Following step 5002, the flowchart 5000 proceeds to step 5003.

In step 5003 of this embodiment, the signal is demodulated. Step 5003 is performed using demodulation function 242 of FIG. 2A or using rake receiver 326 of FIG. Demodulation causes the data signal to be captured from the carrier signal. Following step 5003, the flowchart 5000 proceeds to step 5004.

In step 5004 of this embodiment, the signal strength level is determined. The intensity level is a simple intensity level or a signal ratio for noise such as Eb / Nt. In addition, variables are used to track the performance of the signal over time period 5004b, for example by giving the average signal strength over time. Step 5004 is executed by the channel evaluation function unit 244. The channel evaluation function unit itself can be implemented in the firmware / software unit 310 of FIG. Following step 5004, the flowchart 5000 proceeds to step 5006.

In step 5006 of this embodiment, the multipath signals that have each undergone the previous steps are combined to form a composite signal. Step 5
006 can be performed by the combine function 246 of FIG. 2A. The coupling function itself is
It can be implemented by the firmware / software function unit 310 of FIG. Following step 5006, the flowchart 5000 proceeds to step 5008.

In step 5008 of this embodiment, bit positions are selected for soft symbols. The soft symbol is a continuous 6-bit string of the composite signal evaluated by the decoder. The desired bit position can be separated from the composite signal by a number of techniques including scaling and signal reformatting. Step 5008 can be implemented using the bit selection function 250 of FIGS. 2A and 2B. However, the present invention is suitable for use with a wide range of methods for selecting desired bit positions for soft symbols that depend on the performance of individual multipath signals and / or composite signals. Following step 5008, the flowchart 5000 proceeds to step 5010.

In step 5010 of this embodiment, the signal performance and the corresponding bit position selected for the soft symbol are updated accordingly. Step 5010 may be implemented with a time schedule appropriate for the particular device. For example, updates from time to time may be based on system cycles or other similar criteria. In one embodiment, the updating is based on sampling of non-contiguous signal values, eg, one signal at 125 millisecond cycles. In other embodiments, certain bit values are set as default values for either initial system operation or consistent performance history. Thereafter, the bit positions may change for changing environments, for example when the performance of the signal changes beyond a threshold. Alternatively, the present invention is suitable for a wide range of management techniques that determine when and how bit positions change.

Table 1 below shows FER simulation results using the bit selection process of the present invention. In particular, the HDS attribute defines the real and fractional numbers of the composite signal used for the Viterbi decoder. Scaling indicates how much the composite signal has scaled down from its initial 24 bit length. The Floating and TR45 columns represent floating point transformations of numbers. Finally, the column above each case in the leftmost column shows the K value of the signal, eg 1.2K is a 1200 cycle system.
The cases of different signal reception patterns are shown below the system cycle cases. For example, the attenuation of one finger has a signal to noise ratio Eb / Nt of 9
． It is 6 dB. This is a reasonable case of attenuation. % Listed under each column
The value indicates the effect of the bit selection process. Overall, this table shows the effect on selecting different bit positions for decoding operations.

[0043]

[Table 1] By updating the bits selected for soft symbols accordingly, the invention provides a communication device with greater flexibility. This flexibility adapts the communication device to changing environments, which are suitable for mobile communication devices. Thus, the present invention provides the optimum soft symbol portion of the composite signal for subsequent demodulation. This bit selection process has little headroom. Moreover, it saturates large signal amplitudes. The processing is feasible because the signals are not likely to be erroneously decoded at large amplitudes and these signal amplitudes require less resolution. This strategy gives higher resolution in the original surrounding area and saturates large signal amplitudes.

Although the flowchart 5000 of the present invention illustrates a particular sequence and amount of steps, the present invention is suitable for other embodiments. For example, not all the steps provided in flowchart 5000 are necessary for the present invention. Also, additional steps may be added. In particular, flowchart 5000 is used for composite testing to establish a level of reliability.

Similarly, the sequence of steps can be modified by the application.
Further, although flowchart 5000 is shown as a single continuous process, it may be implemented as a continuous or parallel process. For example, the flowchart 5000 can be repeated continuously or intermittently as sequential signal values.

Many of the instructions for the steps of the flowchart 5000 and the data input / output of the steps utilize the memory 316 and use the processor 314 and / or the processor 31.
Use 7. The storage device of this embodiment may be a permanent memory such as a read only memory (ROM) or a temporary memory such as a random access memory (RAM). Memory 316 may be other types of storage devices that may contain program instructions, such as hard drives, CD-ROMs, and flash memory. Alternatively, the present invention may be implemented using some form of state machine.

With respect to the embodiments described herein, the present invention advantageously provides methods and apparatus for improving the capacity, reliability and performance of digital communications. Specifically, the present invention is
Provided is a method and apparatus for appropriately evaluating received signals for processing to meaningful data such as voice data. Finally, as described herein, the present invention provides a method that overcomes the limitations of the prior art in selecting a portion of a composite signal for decoding. This consequently improves the signal quality and reliability of the communication device.

The foregoing descriptions of specific embodiments of the present invention have been made for the purpose of schematic and description. It is obvious that the above description does not cover the present invention as it is, without limiting it, and that many variations and modifications can be made based on the above teachings. This embodiment has been chosen and described in order to best explain the principles and practical applications of the invention, which will enable those skilled in the art to make various changes, assuming particular use. To optimally utilize the invention and various embodiments. The scope of the present invention is intended to be defined by the appended claims and their equivalents.

[Brief description of drawings]

[Figure 1]   The figure which shows the conventional base station and a mobile telephone.

FIG. 2A is a functional block diagram of a bit selection process performed on a signal according to an embodiment of the present invention in coordination with other communication operations.

FIG. 2B   3 is a detailed functional block diagram of a bit selection engine according to an embodiment of the present invention. FIG.

[FIG. 2C]   3 is a detailed functional block diagram of a pre-processing functional unit according to an embodiment of the present invention. FIG.

[Fig. 2D]   3 is a detailed functional block diagram of a post-processing functional unit according to an embodiment of the present invention. FIG.

FIG. 3 is a hardware block diagram of a communication device used for bit selection processing according to a disclosed embodiment.

FIG. 4 illustrates some exemplary cases of signal performance and impact on bits of the corresponding combined signal, according to one embodiment of the invention.

FIG. 5 is a flow diagram illustrating steps used to implement a method of selecting soft symbols for subsequent operations, eg, decoding operations, in a communication device according to an embodiment of the present invention.

─────────────────────────────────────────────────── ─── Continued front page    (81) Designated countries EP (AT, BE, CH, CY, DE, DK, ES, FI, FR, GB, GR, IE, I T, LU, MC, NL, PT, SE, TR), CN, J P, KR (72) Inventors Daniel, Yen, and Fusia             Dell, California, USA             Marl, Lourdes, Drive, 14113 F term (reference) 5K022 EE01 EE11 EE21 EE31

Claims (12)

[Claims] 1. A method of providing a portion of a signal for subsequent operation in a communication device, comprising: a) receiving the signal at the communication device; b) demodulating the signal; Determining the strength level of the signal; and d) selecting a bit position of the signal for the subsequent operation based on the strength level of the signal. 2. The communication device, a receiver for receiving the signal, a processor connected to the receiver, a computer-readable memory unit connected to the processor,
2. The method of claim 1, wherein the memory unit stores program instructions to be executed via the processor, the method providing a portion of a signal for subsequent operation. the method of. 3. The method is provided by a computer readable medium containing computer readable code for causing the communication device to perform the method providing a portion of a signal for subsequent operation. The method of claim 1, wherein 4. The method according to claim 1, wherein the subsequent operation is a decoding operation. 5. The method according to claim 1, wherein the intensity level is a signal to noise ratio (SNR). 6. The selected bit position is updated as appropriate.
The method described in any one of. 7. The method according to claim 1, wherein the steps a) to c) are performed for each of a plurality of multipath signals. 8. e) combining each of said plurality of multipath signals to produce a composite signal; and f) said based on said intensity level of said signal for each of said plurality of multipath signals. 8. The method of claim 7, further comprising: selecting a bit position of the composite signal for decoding operations. 9. The step of f) selecting bit positions further comprises: f1) determining an average bit position of the composite signal suitable for the ratio of signal to noise; and f2) the average bit. To scale the composite signal around the position,
Multiplying the composite signal by a scale factor. 10. The method of claim 8, wherein the bit position of the composite signal is selected according to a respective reception scenario of the multipath signal. 11. The method of claim 1, wherein the bit position comprises a 6-bit continuous binary number of the composite signal. 12. The method according to claim 1, wherein the communication device is a mobile phone having a code division multiple access (CDMA) configuration.