Patent Publication Number: US-9408094-B2

Title: Apparatus and method for assessing decode reliability of radio transmissions

Description:
CLAIM OF PRIORITY UNDER 35 U.S.C. §119 
     The present Application for Patent claims priority to Provisional Applications No. 61/701,474 entitled “Apparatus and Method for Assessing Decode Reliability of WCDMA Transmissions” and filed on Sep. 14, 2012, and assigned to the assignee hereof and hereby expressly incorporated by reference herein. 
    
    
     BACKGROUND 
     1. Field 
     Aspects of the present disclosure relate generally to wireless communication systems, and more particularly, to an apparatus and method for assessing reliability of decoded voice, data and control channel transmissions. 
     2. Background 
     Wireless communication networks are widely deployed to provide various communication services such as telephony, video, data, messaging, broadcasts, and so on to user equipment (UE). Such networks, which are usually multiple access networks, support communications for multiple users by sharing the available network resources. One example of such a network is the UMTS Terrestrial Radio Access Network (UTRAN). The UTRAN is the radio access network (RAN) defined as a part of the Universal Mobile Telecommunications System (UMTS), a third generation (3G) mobile phone technology supported by the 3rd Generation Partnership Project (3GPP). The UMTS, which is the successor to Global System for Mobile Communications (GSM) technologies, currently supports various air interface standards, such as Wideband-Code Division Multiple Access (WCDMA), Time Division—Code Division Multiple Access (TD-CDMA), and Time Division—Synchronous Code Division Multiple Access (TD-SCDMA). The UMTS also supports enhanced 3G data communications protocols, such as High Speed Packet Access (HSPA), which provides higher data transfer speeds and capacity to associated UMTS networks. High Speed Downlink Packet Access (HSDPA) is a data service offered on the downlink of WCDMA networks. 
     Some wireless communication networks, such as WCDMA, provide early voice frame termination functionality by which early decoding on voice transport channels is attempted by the UE receiver, so that the receiver may be transitioned into a low-power state to preserve battery power of the UE if the early decoding of the voice frame is deemed successful. Some of these voice transport channels do not carry Cyclic Redundancy Check (CRC) bits, which are used for error-detection purposes. In the absence of a CRC on early terminated voice frames, there may be no mechanism for the UE receiver to assess reliability of the early decoded frames, which may adversely affect system performance. Accordingly, there is a need for a mechanism for assessment of the reliability of early decoded voice frames. In addition, decode reliability assessment may be also desired in the context of decoding of control channels, such as a Dedicated Control Channel (DCCH) in WCDMA systems. 
     SUMMARY 
     The following presents a simplified summary of one or more aspects of systems, methods and computer program products for assessing reliability of decoded voice, data and control channel transmissions. This summary is not an extensive overview of all contemplated aspects of the invention, and is intended to neither identify key or critical elements of the invention nor delineate the scope of any or all aspects thereof. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that is presented later. 
     In one aspect, a method, in a UE, for assessing decode reliability of radio frames includes receiving one or more radio frames or parts of a frame on a downlink channel. The method further includes demodulating the received one or more frames or parts of the frame. The method further includes decoding the demodulated one or more frames or parts of the frame. The method further includes computing one or more demodulator-based metrics and one or more decoder-based metrics. The method further includes combining the one or more demodulator-based metrics and the one or more decoder-based metrics using a reliability function that assesses reliability of the decoded one or more frames or parts of the frame. The method further includes accepting or rejecting the decoded one or more frames or parts of the frame based on the assessment of the reliability of said frames or parts of the frame. 
     In another aspect, an apparatus for assessing decode reliability of radio frames includes a receiver configured to receive one or more radio frames or parts of a frame on a downlink channel. The apparatus further includes a demodulator configured to demodulate the received one or more frames or parts of the frame. The apparatus further includes a decoder configured to decode the demodulated one or more frames or parts of the frame. The apparatus further includes a demodulator metrics determiner configured to compute one or more demodulator-based metrics. The apparatus further includes a decoder metric determiner configured to compute one or more decoder-based metrics. The apparatus further includes a metrics combiner configured to combine the one or more demodulator-based metrics and the one or more decoder-based metrics using a reliability function that assesses reliability of the decoded one or more frames or parts of the frame. The apparatus further includes the decoder further configured to accept or reject the decoded one or more frames or parts of the frame based on the assessment of the reliability of said frames or parts of the frame. 
     In another aspect, an apparatus for assessing decode reliability of radio frames includes means for receiving one or more radio frames or parts of a frame on a downlink channel. The apparatus further includes means for demodulating the received one or more frames or parts of the frame. The apparatus further includes means for decoding the demodulated one or more frames or parts of the frame. The apparatus further includes means for computing one or more demodulator-based metrics. The apparatus further includes means for computing one or more decoder-based metrics. The apparatus further includes means for combining the one or more demodulator-based metrics and the one or more decoder-based metrics using a reliability function that assesses reliability of the decoded one or more frames or parts of the frame. The apparatus further includes means for accepting or rejecting the decoded one or more frames or parts of the frame based on the assessment of the reliability of said frames or parts of the frame. 
     In yet another aspect, a computer program product for wireless communication includes a computer-readable medium having at least one instruction executable by a computer to assess decode reliability of radio frames includes codes for receiving one or more radio frames or parts of a frame on a downlink channel. The computer program product further includes at least one instruction executable by the computer to demodulate the received one or more frames or parts of the frame, and at least one instruction executable by the computer to decode the demodulated one or more frames or parts of the frame. The computer program product further includes at least one instruction executable by the computer to compute one or more demodulator-based metrics, and at least one instruction executable by the computer to compute one or more decoder-based metrics. The computer program product further includes at least one instruction executable by the computer to combine the one or more demodulator-based metrics and the one or more decoder-based metrics using a reliability function that assesses reliability of the decoded one or more frames or parts of the frame. Additionally, the computer program product further includes at least one instruction executable by the computer to accept or reject the decoded one or more frames or parts of the frame based on the assessment of the reliability of said frames or parts of the frame. 
     To the accomplishment of the foregoing and related ends, the one or more aspects comprise the features hereinafter fully described and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail certain illustrative features of the one or more aspects. These features are indicative, however, of but a few of the various ways in which the principles of various aspects may be employed, and this description is intended to include all such aspects and their equivalents. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram illustrating one example implementation of a RF receiver. 
         FIG. 2  is a block diagram illustrating one example implementation of a decode assessment module of the RF receiver. 
         FIG. 3  is a flow diagram illustrating an example methodology for assessing reliability of early decoded voice channel frames according to one aspect. 
         FIG. 4  is a flow diagram illustrating an example methodology for assessing reliability of decoded control channel frames according to another aspect. 
         FIG. 5  is a flow diagram illustrating an example methodology for assessing reliability of decoded frames or parts of the frame according to one aspect. 
         FIG. 6  is a block diagram of an example electrical system for assessing reliability of decoded frames by the RF receiver. 
         FIG. 7  is a block diagram illustrating an example of a hardware implementation for an apparatus employing a processing system. 
         FIG. 8  is a block diagram conceptually illustrating an example of a telecommunications system. 
         FIG. 9  is a conceptual diagram illustrating an example of an access network. 
         FIG. 10  is a block diagram conceptually illustrating an example of a Node B in communication with a UE in a telecommunications system. 
     
    
    
     DETAILED DESCRIPTION 
     The detailed description set forth below in connection with the appended drawings is intended as a description of various configurations and is not intended to represent the only configurations in which the concepts described herein may be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of various concepts. However, it will be apparent to those skilled in the art that these concepts may be practiced without these specific details. In some instances, well known structures and components are shown in block diagram form in order to avoid obscuring such concepts. 
       FIG. 1  illustrates an example configuration of a radio frequency (RF) receiver of a user equipment (UE). The receiver  10  includes a RF antenna  11  that receives RF signals, such as voice, data, and control frames on a downlink channel from a base station (e.g., Node B) and transforms them into electromagnetic signals for processing. The electromagnetic signals are transmitted to amplifier circuit  12 , which may include a low noise amplifier (LNA), analog-to-digital converter (ADC), variable gain amplifier (VGA) and automatic gain control (AGC) circuit, which calibrates operating range of the LNA, ADC and VGA. The amplified and digitized signals are then passed to a Rake receiver  13 , which is designed to mitigate the effects of the multipath fading. Rake receiver  13  may include a path search for identifying different propagation paths of the received signal, a channel estimator that estimate channel conditions, such as time delay, amplitude and phase for each path component, and a path combiner that combines strongest multipath components of the received signal into one signal. The resulting signal is then demodulated by the demodulator  16 , such as a QPSK or QAM demodulator. The demodulated signal is passed to decoder  17 , such as Viterbi decoder, which performs decoding of the convolutionally encoded data. The receiver  10  also includes a processor  14 , such as a microprocessor or microcontroller, which executes programs for controlling operation of the components of the receiver  10 , and memory  15  that stores runtime data and programs executable by the processor  14 . 
     For example, a voice call in the WCDMA system may be processed using an Adaptive Multi Rate (AMR) coding scheme in which speech data is encoded into three classes of data bits often called Classes A, B, and C. These three classes have different levels of importance. The received AMR data is processed as three subflows (e.g., one subflow for each class of data) for a Dedicated Traffic Channel (DTCH) at the Radio Link Control (RLC) layer and sent on three separate voice transport channels (channels  1 ,  2  and  3 , respectively for each class of data) at the Medium Access Control (MAC) layer. Each transport channel is associated with a transmission time interval (TTI) that may span one, two, four, or eight 10-millisecond (ms) frames. Also, each transport channel may have different Quality of Service (QoS) requirements, such as service response time, path loss, signal-to-noise ratio, cross-talk, echo, interrupts, frequency response, loudness levels, and other. In addition, only channel  1 , which carriers Class A data, provides CRC bits in each frame, which are used for error correction purposes. 
     As explained above, some wireless systems, such as WCDMA, provide early voice frame termination functionality by which early decoding of radio frames (e.g., parts of a frame) on voice transport channels is attempted by the receiver  10 , so that the receiver  10  may be transitioned into a low-power state to preserve battery power of the UE if the early decode is deemed successful. Some of these voice transport channels do not carry CRC bits, but are, nevertheless, associated with QoS requirements on their residual bit error rate (BER). In the absence of a CRC on early terminated voice frames, the receiver  10  needs another mechanism for assessing reliability of early decodes. 
     In other aspects, the assessment of decode reliability of control channel signaling in the WCDMA system is also desired. For example, CRC false alarms (i.e., CRC passing when it should not) are a concern in the context of decoding signaling messages on the Dedicated Control Channel (DCCH) or other WCDMA control channels. A misinterpreted signaling message may have an unpredictable impact and may cause call drops. Therefore, additional mechanisms for assessing reliability of the DCCH decodes as an enhancement over using just the CRC is desired. 
     To that end, in one aspect, the receiver  10  may include a decode assessment module  18  configured to perform reliability assessment of voice, data and control frames. In one aspect, the module  18  may use various soft metrics, such as SNR from the receiver  10 , to assess reliability of one or more decoded voice, data or control frames or parts of the frame. In another aspect, the module  18  may use soft and hard metrics, such as symbol error counts from a Viterbi decoder  17 , to assess reliability of decoded frames. In another aspect, the module  18  may use a combination of multiple such metrics to generate a binary decision on the reliability of decoding. In another aspect, the module  18  may use a reliability decision function that is independent of the early decode time or which may be tuned to a specific decode time. In yet another aspect, the module  18  may dynamically tune the reliability decision function over time in an adaptive manner to improve reliability of decoded frames or parts of the frames. 
       FIG. 2  illustrate one example implementation of the decode assessment module of a RF receiver, such as a receiver  10  of  FIG. 1 . In one aspect, the decode assessment module  18  may be implemented as a software program stored in memory  15  and executed by the processor  14 . The processor  14  may periodically, e.g., every 10 ms, 14 ms or 20 ms, activate the decode assessment module  18  to assess reliability of decoded radio frames or parts of the frames received from a base station. As shown, the decode assessment module  18  may include a demodulator metrics determiner  22 , a decoder metrics determiner  24 , and a metrics combiner  26 . 
     In one aspect, the demodulator metrics determiner  22  may calculate various front end metrics (also referred as demodulator-based metrics) from the demodulator  16  of the receiver  10 , which can be used to assess reliability of the decoded radio frames or parts of the frame. For example, a demodulator-based metric includes a Signal-to-Noise Ratio (SNR) of the Common Pilot Channel (CPICH). In another aspect, a demodulator-based metric may include a SNR of the Dedicated Physical Channel (DPCH) (also known as DPCH Signal-to-Interference-Ratio Estimate or DPCH SIRE or just SIRE). This metric may be based on signal estimations from one or more of DPCCH-DP, DPCCH-TPC, and DPCCH-TFCI and noise estimations based on one or more of CPICH, DPCCH-DP, DPCCH-TPC, and DPCCH-TFCI. In another aspect, a demodulator-based metric may include a DPCH target SNR (also known as DPCH Signal-to-Interference-Ratio Target or DPCH SIRT or just SIRT). In another aspect, a demodulator-based metric may include a Dedicated Physical Control Channel (DPCCH) energy, which can be computed for each DPCCH sub-field: DP, TPC, and TFCI. In yet another aspect, a demodulator-based metric may include a Dedicated Physical Data Channel (DPDCH) energy, which can be computed for each transport channel on the DPDCH including, for example, the DCCH channel that carries signaling messages. Other types of demodulator-based metrics may be used in other aspects. 
     In another aspect, the decoder metrics determiner  24  of the decode assessment module  18  may calculate various decoder-based metrics from the decoder  17  of the receiver  10 , which can be used to assess reliability of the decoded radio frames or parts of the frame. Consider, for instance, a binary data sequence {d i } that is encoded into the antipodal sequence {c i }. In the simple case of a channel with additive noise, the input to the decoder  17  is a sequence {s i =c i +n i } and the output is {{circumflex over (d)} i }. The decoded data sequence {{circumflex over (d)} i } may then be re-encoded into the antipodal sequence {ĉ i }. The following decoder-based metrics may be generated based on the above decoded data: In one aspect, the decoder-based metric may include a decoder energy metric (EM), which can be computed as a correlation between the input to the decoder and the re-encoded output in the following manner EM=Σs i ĉ i . In another aspect, the decoder-based metric may include a symbol error count (SER) metric may be computed as the number of sign mismatches between the decoder input and the re-encoded output in the following manner SER=Σsign(s i ĉ i ). In yet another aspect, the decoder-based metric may include a Yamamoto quality bit (YQBIT), which can be set to zero if there exists a code-word {c k   i } whose correlation with the decoder input is within a threshold of the energy metric (EM). The threshold Y T  is typically programmable. The Yamamoto quality bit metric may be determined using the following expression: YQBIT=0 Σs i ĉ i −Σs i c k   i &lt;Y T . In yet another aspect, the decoder-based metric may include one or more Viterbi Decoder (VD) Path metrics, such as a minimum (Mmin), maximum (Mmax), and zero-state (M 0 ) path metrics at the point of expected trellis termination. Other types of decoder-based metrics may be used in other aspects. 
     In another aspect, the metrics combiner  26  of decode assessment module  18  combines one or more demodulator-based metrics and decoder-based metrics using a reliability function in order to assess reliability of an decoded radio frames or parts of the frame. The combination process will be illustrated based on the example of an AMR 12.k voice call in the WCDMA system. Particularly, an AMR 12.2 k call uses three transport channels for the voice radio bearer: Transport Channel A with a 12 bit CRC; and Transport Channels B and C that do not have a CRC. Combiner  26  may use the following reliability function to assess reliability of the early decode voice frames:
         CRC of A has passed   AND   SIRE&gt;SIRT+K 1  dB OR YQBIT of B is 1 OR SER of B&lt;K 2     AND   SIRE&gt;SIRT+K 3  dB OR YQBIT of C is 1 OR SER of C&lt;K 4         

     The parameters of this reliability function may be optimized offline in a simulation environment or may be adaptively updated in the course of the voice call. Example values of the parameters used in the above reliability function may be K 1 =3 dB, K 2 =12, K 3 =3 dB, K 4 =8. Note that neither the metrics nor the reliability functions are uniquely determined and other variations of the above function can be used. It should be also noted that, in one aspect, the decode assessment module  18  may use a reliability function that is independent of the early decode time or may be tuned to the specific decode time. In another aspect, the early decode assessment module  18  may dynamically tune the reliability function over time in an adaptive manner to further improve assessment of reliability of early decoded voice channels. 
       FIG. 3  illustrates an example implementation of the methodology for assessing reliability of early decoded voice frames according to the principles disclosed herein. In one aspect, the method  300  may be implemented in the decode assessment module  18  ( FIGS. 1 and 2 ) of the receiver  10  of  FIG. 1 . At step  305 , the method  300  includes receiving one or more voice frames or parts of voice frames on AMR-A, AMR-B, AMR-C downlink channels. At step  310 , the method  300  includes demodulating the received frames. At step  315 , the method  300  includes performing early decode of the received parts of the frames. At step  320 , the method  300  includes checking if Channel A full-rate transport format passed the CRC. If CRC is passed, at step  325 , the method  300  includes checking if energy of Channels B and C is above a demodulator-base metric: (AMR-B_Energy+AMR-C_Energy)&gt;K 0 *DPCCH_Energy. If, at step  325 , the answer is No, then, at step  355 , the method  300  includes declaring early decode failure in which case the decoder  17  of the receiver  10  may continue decoding received voice frames. If, at step  325 , the answer is Yes, then the method  300  checks, at step  330 , if SIRE is greater than demodulator-based metric K 5 *SIR_TARGET (SIRT). If, at step  330 , the answer is Yes, then early decode of the voice frame on Channel A is considered successful, at step  335 . If, at step  330 , the answer is No, then, at step  360 , the method  300  includes checking decoder-based metrics: (YQBIT of AMR-B=1) AND (YQBIT of AMR-C=1). If, at step  360 , the answer is Yes, then early decode of the voice frame on Channel A is considered successful, at step  335 . If, at step  360 , the answer is No, then the method  300  includes checking, at step  380 , another set of decoder-based metrics for Channel B: (SER of AMR-B&lt;K 1 ) AND ((M 0 −M min )/(M max −M min ) of AMR-B&lt;K 2 ). If, at step  380 , the answer is Yes, then the method  300  includes checking, at step  385 , another set of decoder-based metrics for Channel C: (SER of AMR-C&lt;K 3 ) AND ((M 0 −M min )/(M max −M min ) of AMR-C&lt;K 4 ). If, at step  385 , the answer is Yes, then early decode of all AMR channels is considered successful, at step  335 . If, at step  385 , the answer is No, then, at step  355 , the method  300  includes declaring early decode failure in which case the decoder  17  of the receiver  10  may continue decoding received voice frames. If, at step  320 , the Channel A full-rate transport format did not pass the CRC, then, at step  340 , the method  300  includes checking if AMR-A Silence Indicator (SID) Transport format passed CRC. If, SID CRC is passed, then, at step  345 , the method  300  includes checking if energy of Channels B and C is below a demodulator-base metric: (AMR-B_Energy+AMR-C_Energy)&lt;K 0 *DPCCH_Energy. If, at step  345 , the answer is Yes, then SID is successfully decoded at step  350 ; otherwise, at step  355 , the method  300  includes declaring early decode failure in which case the decoder  17  of the receiver  10  may continue decoding received voice frames. If, at step  340 , the SID CRC failed, then, at step  365 , the method  300  further includes checking if AMR-A Null Transport format passed the CRC. If the Null CRC is passed, then, at step  370 , the method  300  includes checking if energy of Channels B and C is below a demodulator-base metric: (AMR-B_Energy+AMR-C_Energy)&lt;K 0 *DPCCH_Energy. If, at step  370 , the answer is Yes, then NULL is successfully decoded at step  375 ; otherwise, at step  355 , the method  300  includes declaring early decode failure in which case the decoder  17  of the receiver  10  may continue decoding received voice frames. 
       FIG. 4  illustrates an example implementation of the methodology for assessing reliability of decoded control channel DCCH frames according to the principles disclosed herein. In one aspect, the method  400  may be implemented in the decode assessment module  18  of the receiver  10  of  FIGS. 1 and 2 . At step  405 , the method  400  includes demodulating one or more DCCH frames or parts of the DCCH frame. At step  410 , the method  400  includes decoding one or more DCCH frames or parts of the DCCH frame. At step  415 , the method  400  includes checking if DCCH frame passed the CRC. If CRC did not pass, then at step  420 , the method  400  includes discarding the DCCH frame. If CRC passed, then, at step  425 , the method  400  includes checking if the DCCH frame is indicated to be erroneous by the Radio Link Control (RLC) layer. If no RLC errors, then at step  430 , the method  400  includes continue processing the DCCH frame. If, at step  425 , the RLC layer found errors in the DCCH frame, then, at step  435 , the method  400  includes computing demodulator-based metric DCCH_Energy and decoder-based metric SER of DCCH, and combining these metrics using the following reliability function: DCCH_Energy&gt;K 0 *DPCCH_Energy &amp;&amp; SER of DCCH&lt;K 1 . If the reliability function is passed, then, at step  440 , the method  400  includes initiating RLC Reset procedure. If the reliability function is not passed, then, at step  420 , the method  400  includes discarding the DCCH frame. 
       FIG. 5  is an example methodology for assessing reliability of decoded frames by the RF receiver, such as receiver  10  of  FIG. 1  that includes a decode assessment module  18  of  FIGS. 1 and 2 . At step  505 , the method  500  includes receiving one or more radio frames or parts of a frame on a downlink channel form a base station. For example, in one aspect, the RF receiver  10  includes a RF antenna  11  and amplifier circuitry  12  for receiving RF signals containing voice, data and control frames. At step  510 , the method  500  includes demodulating one or more radio frames of parts of the frame. In one aspect, the receiver  10  includes a demodulator  16  for demodulating voice, data and control frames or parts of the frame. At step  515 , the method  500  includes decoding the demodulated one or more frames or parts of the frame. In one aspect, the receiver  10  includes a decoder  17  for decoding demodulated frames or parts of the frame. At step  520 , the method  500  includes computing one or more demodulator-based metrics. In one aspect, the receiver  10  includes a decode assessment module  18 , which in turn includes a demodulator metric determiner  22  ( FIG. 2 ) for computing one or more demodulator-based metrics, such as a SIRE. At step  525 , the method  500  includes computing one or more decoder-based metrics. In one aspect, the receiver  10  includes a decode assessment module  18 , which in turn includes a decoder metric determiner  24  ( FIG. 2 ) for computing one or more decoder-based metrics, such as EM, SER, YQBIT. At step  530 , the method  500  includes combining one or more demodulator metrics and one or more decoder metrics using a reliability function. In one aspect, the receiver  10  includes an early decode assessment module  18 , which in turn includes a metric combiner  26  ( FIG. 2 ) for combining one or more demodulator metrics and one or more decoder metrics using a reliability function. At step  535 , the method  500  includes assessing reliability of the early decoded voice frames based on the decision of the reliability function. In one aspect, the early decode assessment module  18  of receiver  10  assesses reliability of the decoded frames based on the decision of the reliability function. At step  540 , the method  500  includes accepting or rejecting the one or more decoded frames based on the assessment of reliability of the decoded frames. In one aspect, if the early decode assessment module  18  of the receiver  10  determines that the early decode attempt was successful, it may instruct processor  14  to accept the early decoded frames and terminate reception of voice data frames to conserve battery power of the UE. However, if the early decode assessment module  18  determines that the early decode attempt was unsuccessful, it may instruct processor  14  to reject the early decoded frames and continue reception of voice data frames and retry decoding at a later time, or request retransmission of damaged voice frames from the base station. 
       FIG. 6  illustrates an example system  600  for assessing reliability of decoded frames by the RF receiver, such as receiver  10  of  FIG. 1  that includes a decode assessment module  18  of  FIGS. 1 and 2 . It is to be appreciated that system  600  is represented as including functional blocks, which can be functional blocks that represent functions of a RF receiver, such as receiver  10  of  FIG. 1 , and/or decode assessment module  18  of  FIGS. 1 and 2 , implemented by a processor, software, or combination thereof (e.g., firmware). System  600  includes a logical grouping  605  of electrical components that can act in conjunction. For instance, logical grouping  605  can include an electrical component  610  for receiving a voice, data or control frame. Moreover, logical grouping  605  can include an electrical component  615  for demodulating one or more frames or parts of the frame. Moreover, logical grouping  605  can include an electrical component  620  for decoding of one or more demodulated frames or parts of the frame. Moreover, logical grouping  605  can include an electrical component  625  for computing one or more demodulator-based metrics. Moreover, logical grouping  605  can include an electrical component  630  for computing one or more decoder-based metrics. Moreover, logical grouping  605  can include an electrical component  635  for combining demodulator metrics and decoder metrics using a reliability function. Moreover, logical grouping  605  can include an electrical component  640  for assessing reliability of the decoded frames based on the reliability function. Moreover, logical grouping  605  can include an electrical component  645  for accepting or rejecting the early decoded frames based on assessment of their reliability. Additionally, system  600  can include a memory  650  that retains instructions for executing functions associated with the electrical components  610 - 645 , stores data used or obtained by the electrical components  610 - 645 , etc. While shown as being external to memory  650 , it is to be understood that one or more of the electrical components  610 - 645  can exist within memory  650 . In one example, electrical components  610 - 645  can comprise at least one processor, or each electrical component  610 - 645  can be a corresponding module of at least one processor. Moreover, in an additional or alternative example, electrical components  610 - 645  can be a computer program product including a computer readable medium, where each of the electrical components  610 - 645  can be corresponding code. 
       FIG. 7  is a block diagram illustrating an example of a hardware implementation for an apparatus  700 , such as a UE, employing a processing system  714 , such as a RF receiver  10  of  FIG. 1  that includes a decode assessment module  18  of  FIGS. 1 and 2 , which is configured to perform the assessment of the reliability of decoded frames according to various aspects disclosed herein. In this example, the processing system  714  may be implemented with a bus architecture, represented generally by the bus  702 . The bus  702  may include any number of interconnecting buses and bridges depending on the specific application of the processing system  714  and the overall design constraints. The bus  702  links together various circuits including one or more processors, represented generally by the processor  704 , and computer-readable media, represented generally by the computer-readable medium  706 . The bus  702  may also link various other circuits such as timing sources, peripherals, voltage regulators, and power management circuits, which are well known in the art, and therefore, will not be described any further. A bus interface  708  provides an interface between the bus  702  and a transceiver  710 . The transceiver  710  provides a means for communicating with various other apparatus over a transmission medium. Depending upon the nature of the apparatus, a user interface  712  (e.g., keypad, display, speaker, microphone, joystick) may also be provided. 
     The processor  704  is responsible for managing the bus  702  and general processing, including the execution of software stored on the computer-readable medium  706 . The software, when executed by the processor  104 , causes the processing system  714  to perform the various functions described infra for any particular apparatus. In one aspect, the processor  704  includes a decode assessment module  18  that performs assessment of the reliability of decoded voice, data and control frames. The computer-readable medium  706  may also be used for storing data that is manipulated by the processor  704  when executing software, such as the module  18 . 
     The systems and methods for performing the assessment of the reliability of early decoded frames according to various aspects presented throughout this disclosure may be implemented across a broad variety of telecommunication systems, network architectures, and communication standards. By way of example and without limitation, the aspects of the present disclosure illustrated in  FIG. 8  are presented with reference to a UMTS system  200  employing a W-CDMA air interface. A UMTS network includes three interacting domains: a Core Network (CN)  204 , a UMTS Terrestrial Radio Access Network (UTRAN)  202 , and User Equipment (UE)  210 . In one aspect, the UE  210  includes a RF receiver  10  of  FIG. 1 , which includes decode assessment module  18  of  FIGS. 1 and 2 . In this example, the UTRAN  202  provides various wireless services including telephony, video, data, messaging, broadcasts, and/or other services. The UTRAN  202  may include a plurality of Radio Network Subsystems (RNSs) such as an RNS  207 , each controlled by a respective Radio Network Controller (RNC) such as an RNC  206 . Here, the UTRAN  202  may include any number of RNCs  206  and RNSs  207  in addition to the RNCs  206  and RNSs  207  illustrated herein. The RNC  206  is an apparatus responsible for, among other things, assigning, reconfiguring and releasing radio resources within the RNS  207 . The RNC  206  may be interconnected to other RNCs (not shown) in the UTRAN  202  through various types of interfaces such as a direct physical connection, a virtual network, or the like, using any suitable transport network. 
     Communication between a UE  210  and a Node B  208  may be considered as including a physical (PHY) layer and a medium access control (MAC) layer. Further, communication between a UE  210  and an RNC  206  by way of a respective Node B  208  may be considered as including a radio resource control (RRC) layer. In the instant specification, the PHY layer may be considered layer  1 ; the MAC layer may be considered layer  2 ; and the RRC layer may be considered layer  3 . Information hereinbelow utilizes terminology introduced in the RRC Protocol Specification, 3GPP TS 25.331 v9.1.0, incorporated herein by reference. 
     The geographic region covered by the RNS  207  may be divided into a number of cells, with a radio transceiver apparatus serving each cell. A radio transceiver apparatus is commonly referred to as a Node B in UMTS applications, but may also be referred to by those skilled in the art as a base station (BS), a base transceiver station (BTS), a radio base station, a radio transceiver, a transceiver function, a basic service set (BSS), an extended service set (ESS), an access point (AP), or some other suitable terminology. For clarity, three Node Bs  208  are shown in each RNS  207 ; however, the RNSs  207  may include any number of wireless Node Bs. The Node Bs  208  provide wireless access points to a CN  204  for any number of UEs  210 . Examples of a UE  210  include a cellular phone, a smart phone, a session initiation protocol (SIP) phone, a laptop, a notebook, a netbook, a smartbook, a personal digital assistant (PDA), a satellite radio, a global positioning system (GPS) device, a multimedia device, a video device, a digital audio player (e.g., MP3 player), a camera, a game console, or any other similar functioning device. The UE  210  may also be referred to by those skilled in the art as a mobile station, a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communications device, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handset, a terminal, a user agent, a mobile client, a client, or some other suitable terminology. In a UMTS system, the UE  210  may further include a universal subscriber identity module (USIM)  211 , which contains a user&#39;s subscription information to a network. For illustrative purposes, one UE  210  is shown in communication with a number of the Node Bs  208 . The DL, also called the forward link, refers to the communication link from a Node B  208  to a UE  210 , and the UL, also called the reverse link, refers to the communication link from a UE  210  to a Node B  208 . 
     The CN  204  interfaces with one or more access networks, such as the UTRAN  202 . As shown, the CN  204  is a GSM core network. However, as those skilled in the art will recognize, the various concepts presented throughout this disclosure may be implemented in a RAN, or other suitable access network, to provide UEs with access to types of CNs other than GSM networks. 
     The CN  204  includes a circuit-switched (CS) domain and a packet-switched (PS) domain. Some of the circuit-switched elements are a Mobile services Switching Centre (MSC), a Visitor location register (VLR) and a Gateway MSC. Packet-switched elements include a Serving GPRS Support Node (SGSN) and a Gateway GPRS Support Node (GGSN). Some network elements, like EIR, HLR, VLR and AuC may be shared by both of the circuit-switched and packet-switched domains. In the illustrated example, the CN  204  supports circuit-switched services with a MSC  212  and a GMSC  214 . In some applications, the GMSC  214  may be referred to as a media gateway (MGW). One or more RNCs, such as the RNC  206 , may be connected to the MSC  212 . The MSC  212  is an apparatus that controls call setup, call routing, and UE mobility functions. The MSC  212  also includes a VLR that contains subscriber-related information for the duration that a UE is in the coverage area of the MSC  212 . The GMSC  214  provides a gateway through the MSC  212  for the UE to access a circuit-switched network  216 . The GMSC  214  includes a home location register (HLR)  215  containing subscriber data, such as the data reflecting the details of the services to which a particular user has subscribed. The HLR is also associated with an authentication center (AuC) that contains subscriber-specific authentication data. When a call is received for a particular UE, the GMSC  214  queries the HLR  215  to determine the UE&#39;s location and forwards the call to the particular MSC serving that location. 
     The CN  204  also supports packet-data services with a serving GPRS support node (SGSN)  218  and a gateway GPRS support node (GGSN)  220 . GPRS, which stands for General Packet Radio Service, is designed to provide packet-data services at speeds higher than those available with standard circuit-switched data services. The GGSN  220  provides a connection for the UTRAN  202  to a packet-based network  222 . The packet-based network  222  may be the Internet, a private data network, or some other suitable packet-based network. The primary function of the GGSN  220  is to provide the UEs  210  with packet-based network connectivity. Data packets may be transferred between the GGSN  220  and the UEs  210  through the SGSN  218 , which performs primarily the same functions in the packet-based domain as the MSC  212  performs in the circuit-switched domain. 
     An air interface for UMTS may utilize a spread spectrum Direct-Sequence Code Division Multiple Access (DS-CDMA) system. The spread spectrum DS-CDMA spreads user data through multiplication by a sequence of pseudorandom bits called chips. The “wideband” W-CDMA air interface for UMTS is based on such direct sequence spread spectrum technology and additionally calls for a frequency division duplexing (FDD). FDD uses a different carrier frequency for the UL and DL between a Node B  208  and a UE  210 . Another air interface for UMTS that utilizes DS-CDMA, and uses time division duplexing (TDD), is the TD-SCDMA air interface. Those skilled in the art will recognize that although various examples described herein may refer to a W-CDMA air interface, the underlying principles may be equally applicable to a TD-SCDMA air interface. 
     An HSPA air interface includes a series of enhancements to the 3G/W-CDMA air interface, facilitating greater throughput and reduced latency. Among other modifications over prior releases, HSPA utilizes hybrid automatic repeat request (HARQ), shared channel transmission, and adaptive modulation and coding. The standards that define HSPA include HSDPA (high speed downlink packet access) and HSUPA (high speed uplink packet access, also referred to as enhanced uplink, or EUL). 
     HSDPA utilizes as its transport channel the high-speed downlink shared channel (HS-DSCH). The HS-DSCH is implemented by three physical channels: the high-speed physical downlink shared channel (HS-PDSCH), the high-speed shared control channel (HS-SCCH), and the high-speed dedicated physical control channel (HS-DPCCH). 
     Among these physical channels, the HS-DPCCH carries the HARQ ACK/NACK signaling on the uplink to indicate whether a corresponding packet transmission was decoded successfully. That is, with respect to the downlink, the UE  210  provides feedback to the node B  208  over the HS-DPCCH to indicate whether it correctly decoded a packet on the downlink. 
     HS-DPCCH further includes feedback signaling from the UE  210  to assist the node B  208  in taking the right decision in terms of modulation and coding scheme and precoding weight selection, this feedback signaling including the CQI and PCI. 
     “HSPA Evolved” or HSPA+ is an evolution of the HSPA standard that includes MIMO and 64-QAM, enabling increased throughput and higher performance. That is, in an aspect of the disclosure, the node B  208  and/or the UE  210  may have multiple antennas supporting MIMO technology. The use of MIMO technology enables the node B  208  to exploit the spatial domain to support spatial multiplexing, beamforming, and transmit diversity. 
     Multiple Input Multiple Output (MIMO) is a term generally used to refer to multi-antenna technology, that is, multiple transmit antennas (multiple inputs to the channel) and multiple receive antennas (multiple outputs from the channel). MIMO systems generally enhance data transmission performance, enabling diversity gains to reduce multipath fading and increase transmission quality, and spatial multiplexing gains to increase data throughput. 
     Spatial multiplexing may be used to transmit different streams of data simultaneously on the same frequency. The data steams may be transmitted to a single UE  210  to increase the data rate or to multiple UEs  210  to increase the overall system capacity. This is achieved by spatially precoding each data stream and then transmitting each spatially precoded stream through a different transmit antenna on the downlink. The spatially precoded data streams arrive at the UE(s)  210  with different spatial signatures, which enables each of the UE(s)  210  to recover the one or more the data streams destined for that UE  210 . On the uplink, each UE  210  may transmit one or more spatially precoded data streams, which enables the node B  208  to identify the source of each spatially precoded data stream. 
     Spatial multiplexing may be used when channel conditions are good. When channel conditions are less favorable, beamforming may be used to focus the transmission energy in one or more directions, or to improve transmission based on characteristics of the channel. This may be achieved by spatially precoding a data stream for transmission through multiple antennas. To achieve good coverage at the edges of the cell, a single stream beamforming transmission may be used in combination with transmit diversity. 
     Generally, for MIMO systems utilizing n transmit antennas, n transport blocks may be transmitted simultaneously over the same carrier utilizing the same channelization code. Note that the different transport blocks sent over the n transmit antennas may have the same or different modulation and coding schemes from one another. 
     On the other hand, Single Input Multiple Output (SIMO) generally refers to a system utilizing a single transmit antenna (a single input to the channel) and multiple receive antennas (multiple outputs from the channel). Thus, in a SIMO system, a single transport block is sent over the respective carrier. 
       FIG. 9  illustrates an access network  900  in a UTRAN architecture in which various aspects of systems and methods for performing the assessment of the reliability of early decoded frames can be implemented. In particular, network  900  may include one or more UEs having RF receiver  10  of  FIG. 1  and/or decode assessment module  18  of  FIGS. 1 and 2 . The multiple access wireless communication system includes multiple cellular regions (cells), including cells  902 ,  904 , and  906 , each of which may include one or more sectors. The multiple sectors can be formed by groups of antennas with each antenna responsible for communication with UEs in a portion of the cell. For example, in cell  902 , antenna groups  912 ,  914 , and  916  may each correspond to a different sector. In cell  304 , antenna groups  918 ,  920 , and  922  each correspond to a different sector. In cell  906 , antenna groups  924 ,  926 , and  928  each correspond to a different sector. The cells  902 ,  904  and  906  may include several wireless communication devices, e.g., UEs, which may be in communication with one or more sectors of each cell  902 ,  904  or  306 . For example, UEs  930  and  932  may be in communication with Node B  942 , UEs  934  and  936  may be in communication with Node B  944 , and UEs  938  and  940  can be in communication with Node B  946 . Here, each Node B  942 ,  944 ,  946  is configured to provide an access point to a CN  204  (see  FIG. 8 ) for all the UEs  930 ,  932 ,  934 ,  936 ,  938 ,  940  in the respective cells  902 ,  904 , and  906 . In one aspect, the UEs  930 ,  932 ,  934 ,  936 ,  938 ,  940  may include RF receiver  10  of  FIG. 1 , which include decode assessment module  18  of  FIGS. 1 and 2 . 
     As the UE  934  moves from the illustrated location in cell  904  into cell  906 , a serving cell change (SCC) or handover may occur in which communication with the UE  934  transitions from the cell  904 , which may be referred to as the source cell, to cell  906 , which may be referred to as the target cell. Management of the handover procedure may take place at the UE  934 , at the Node Bs corresponding to the respective cells, at a RNC  206  (see  FIG. 8 ), or at another suitable node in the wireless network. For example, during a call with the source cell  904 , or at any other time, the UE  934  may monitor various parameters of the source cell  904  as well as various parameters of neighboring cells such as cells  906  and  902 . Further, depending on the quality of these parameters, the UE  934  may maintain communication with one or more of the neighboring cells. During this time, the UE  934  may maintain an Active Set, that is, a list of cells that the UE  934  is simultaneously connected to (i.e., the UTRA cells that are currently assigning a downlink dedicated physical channel DPCH or fractional downlink dedicated physical channel F-DPCH to the UE  934  may constitute the Active Set). 
     The modulation and multiple access scheme employed by the access network  900  may vary depending on the particular telecommunications standard being deployed. By way of example, the standard may include Evolution-Data Optimized (EV-DO) or Ultra Mobile Broadband (UMB). EV-DO and UMB are air interface standards promulgated by the 3rd Generation Partnership Project 2 (3GPP2) as part of the CDMA2000 family of standards and employs CDMA to provide broadband Internet access to mobile stations. The standard may alternately be Universal Terrestrial Radio Access (UTRA) employing Wideband-CDMA (W-CDMA) and other variants of CDMA, such as TD-SCDMA; Global System for Mobile Communications (GSM) employing TDMA; and Evolved UTRA (E-UTRA), Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, and Flash-OFDM employing OFDMA. UTRA, E-UTRA, UMTS, LTE, LTE Advanced, and GSM are described in documents from the 3GPP organization. CDMA2000 and UMB are described in documents from the 3GPP2 organization. The actual wireless communication standard and the multiple access technology employed will depend on the specific application and the overall design constraints imposed on the system. 
       FIG. 10  is a block diagram of a Node B  1010  in communication with a UE  1050 , where the Node B  510  may be the Node B  208  in  FIG. 8 . In one aspect, the UE  1050  includes a RF receiver  10  of  FIG. 1 , which in turn includes decode assessment module  18  of  FIGS. 1 and 2 , which is configured to perform the assessment of the reliability of early decoded frames according to various aspects disclosed herein. In the downlink communication, a transmit processor  1020  may receive data from a data source  1012  and control signals from a controller/processor  1040 . The transmit processor  1020  provides various signal processing functions for the data and control signals, as well as reference signals (e.g., pilot signals). For example, the transmit processor  1020  may provide cyclic redundancy check (CRC) codes for error detection, coding and interleaving to facilitate forward error correction (FEC), mapping to signal constellations based on various modulation schemes (e.g., binary phase-shift keying (BPSK), quadrature phase-shift keying (QPSK), M-phase-shift keying (M-PSK), M-quadrature amplitude modulation (M-QAM), and the like), spreading with orthogonal variable spreading factors (OVSF), and multiplying with scrambling codes to produce a series of symbols. Channel estimates from a channel processor  1044  may be used by a controller/processor  1040  to determine the coding, modulation, spreading, and/or scrambling schemes for the transmit processor  1020 . These channel estimates may be derived from a reference signal transmitted by the UE  1050  or from feedback from the UE  1050 . The symbols generated by the transmit processor  1020  are provided to a transmit frame processor  1030  to create a frame structure. The transmit frame processor  1030  creates this frame structure by multiplexing the symbols with information from the controller/processor  1040 , resulting in a series of frames. The frames are then provided to a transmitter  1032 , which provides various signal conditioning functions including amplifying, filtering, and modulating the frames onto a carrier for downlink transmission over the wireless medium through antenna  1034 . The antenna  1034  may include one or more antennas, for example, including beam steering bidirectional adaptive antenna arrays or other similar beam technologies. 
     At the UE  1050 , a receiver  1054  receives the downlink transmission through an antenna  1052  and processes the transmission to recover the information modulated onto the carrier. The information recovered by the receiver  1054  is provided to a receive frame processor  1060 , which parses each frame, and provides information from the frames to a channel processor  1094  and the data, control, and reference signals to a receive processor  1070 . The receive processor  1070  then performs the inverse of the processing performed by the transmit processor  1020  in the Node B  1010 . More specifically, the receive processor  1070  descrambles and despreads the symbols, and then determines the most likely signal constellation points transmitted by the Node B  1010  based on the modulation scheme. These soft decisions may be based on channel estimates computed by the channel processor  1094 . The soft decisions are then decoded and deinterleaved to recover the data, control, and reference signals. The CRC codes are then checked to determine whether the frames were successfully decoded. The data carried by the successfully decoded frames will then be provided to a data sink  1072 , which represents applications running in the UE  1050  and/or various user interfaces (e.g., display). Control signals carried by successfully decoded frames will be provided to a controller/processor  1090 . When frames are unsuccessfully decoded by the receiver processor  1070 , the controller/processor  1090  may also use an acknowledgement (ACK) and/or negative acknowledgement (NACK) protocol to support retransmission requests for those frames. 
     In the uplink, data from a data source  1078  and control signals from the controller/processor  1090  are provided to a transmit processor  1080 . The data source  1078  may represent applications running in the UE  1050  and various user interfaces (e.g., keyboard). Similar to the functionality described in connection with the downlink transmission by the Node B  1010 , the transmit processor  1080  provides various signal processing functions including CRC codes, coding and interleaving to facilitate FEC, mapping to signal constellations, spreading with OVSFs, and scrambling to produce a series of symbols. Channel estimates, derived by the channel processor  1094  from a reference signal transmitted by the Node B  1010  or from feedback contained in the midamble transmitted by the Node B  1010 , may be used to select the appropriate coding, modulation, spreading, and/or scrambling schemes. The symbols produced by the transmit processor  1080  will be provided to a transmit frame processor  1082  to create a frame structure. The transmit frame processor  1082  creates this frame structure by multiplexing the symbols with information from the controller/processor  1090 , resulting in a series of frames. The frames are then provided to a transmitter  1056 , which provides various signal conditioning functions including amplification, filtering, and modulating the frames onto a carrier for uplink transmission over the wireless medium through the antenna  1052 . 
     The uplink transmission is processed at the Node B  1010  in a manner similar to that described in connection with the receiver function at the UE  1050 . A receiver  1035  receives the uplink transmission through the antenna  1034  and processes the transmission to recover the information modulated onto the carrier. The information recovered by the receiver  1035  is provided to a receive frame processor  1036 , which parses each frame, and provides information from the frames to the channel processor  544  and the data, control, and reference signals to a receive processor  1038 . The receive processor  1038  performs the inverse of the processing performed by the transmit processor  1080  in the UE  1050 . The data and control signals carried by the successfully decoded frames may then be provided to a data sink  1039  and the controller/processor, respectively. If some of the frames were unsuccessfully decoded by the receive processor, the controller/processor  1040  may also use an acknowledgement (ACK) and/or negative acknowledgement (NACK) protocol to support retransmission requests for those frames. 
     The controller/processors  1040  and  1090  may be used to direct the operation at the Node B  1010  and the UE  1050 , respectively. For example, the controller/processors  1040  and  1090  may provide various functions including timing, peripheral interfaces, voltage regulation, power management, and other control functions. The computer readable media of memories  1042  and  1092  may store data and software for the Node B  1010  and the UE  1050 , respectively. A scheduler/processor  1046  at the Node B  1010  may be used to allocate resources to the UEs and schedule downlink and/or uplink transmissions for the UEs. 
     Several aspects of a telecommunications system have been presented with reference to a W-CDMA system. As those skilled in the art will readily appreciate, various aspects described throughout this disclosure may be extended to other telecommunication systems, network architectures and communication standards. 
     By way of example, various aspects may be extended to other UMTS systems such as TD-SCDMA, High Speed Downlink Packet Access (HSDPA), High Speed Uplink Packet Access (HSUPA), High Speed Packet Access Plus (HSPA+) and TD-CDMA. Various aspects may also be extended to systems employing Long Term Evolution (LTE) (in FDD, TDD, or both modes), LTE-Advanced (LTE-A) (in FDD, TDD, or both modes), CDMA2000, Evolution-Data Optimized (EV-DO), Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Ultra-Wideband (UWB), Bluetooth, and/or other suitable systems. The actual telecommunication standard, network architecture, and/or communication standard employed will depend on the specific application and the overall design constraints imposed on the system. 
     In accordance with various aspects of the disclosure, an element, or any portion of an element, or any combination of elements may be implemented with a “processing system” that includes one or more processors. Examples of processors include microprocessors, microcontrollers, digital signal processors (DSPs), field programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, gated logic, discrete hardware circuits, and other suitable hardware configured to perform the various functionality described throughout this disclosure. One or more processors in the processing system may execute software. Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise. The software may reside on a computer-readable medium. The computer-readable medium may be a non-transitory computer-readable medium. A non-transitory computer-readable medium includes, by way of example, a magnetic storage device (e.g., hard disk, floppy disk, magnetic strip), an optical disk (e.g., compact disk (CD), digital versatile disk (DVD)), a smart card, a flash memory device (e.g., card, stick, key drive), random access memory (RAM), read only memory (ROM), programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), a register, a removable disk, and any other suitable medium for storing software and/or instructions that may be accessed and read by a computer. The computer-readable medium may also include, by way of example, a carrier wave, a transmission line, and any other suitable medium for transmitting software and/or instructions that may be accessed and read by a computer. The computer-readable medium may be resident in the processing system, external to the processing system, or distributed across multiple entities including the processing system. The computer-readable medium may be embodied in a computer-program product. By way of example, a computer-program product may include a computer-readable medium in packaging materials. Those skilled in the art will recognize how best to implement the described functionality presented throughout this disclosure depending on the particular application and the overall design constraints imposed on the overall system. 
     It is to be understood that the specific order or hierarchy of steps in the methods disclosed is an illustration of exemplary processes. Based upon design preferences, it is understood that the specific order or hierarchy of steps in the methods may be rearranged. The accompanying method claims present elements of the various steps in a sample order, and are not meant to be limited to the specific order or hierarchy presented unless specifically recited therein. 
     The previous description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects. Thus, the claims are not intended to be limited to the aspects shown herein, but is to be accorded the full scope consistent with the language of the claims, wherein reference to an element in the singular is not intended to mean “one and only one” unless specifically so stated, but rather “one or more.” Unless specifically stated otherwise, the term “some” refers to one or more. A phrase referring to “at least one of” a list of items refers to any combination of those items, including single members. As an example, “at least one of: a, b, or c” is intended to cover: a; b; c; a and b; a and c; b and c; and a, b and c. All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. No claim element is to be construed under the provisions of 35 U.S.C. §112, sixth paragraph, unless the element is expressly recited using the phrase “means for” or, in the case of a method claim, the element is recited using the phrase “step for.”