WO2016026326A1

WO2016026326A1 - Gap detection for timing acqusition in wireless communications

Info

Publication number: WO2016026326A1
Application number: PCT/CN2015/077950
Authority: WO
Inventors: Jinghu Chen; Insung Kang; Hari Sankar; Qiang Shen; Jia Tang; Pouya Tehrani; Shiau-He Tsai
Original assignee: Qualcomm Incorporated
Priority date: 2014-08-19
Filing date: 2015-04-30
Publication date: 2016-02-25
Also published as: WO2016026077A1

Abstract

Aspects described herein relate to performing gap detection for a timing acquisition in a wireless network. A gap detection can be performed for identifying a gap position in a signal received in a frequency band. A gap detection metric for the gap position identified by the gap detection can be determined, and it can be determined whether the signal is associated with a first radio access technology based. This determination can be based at least in part on determining whether the gap detection metric achieves a first threshold value, and performing one or more validating checks to further validate whether the signal is associated with the first radio access technology.

Description

GAP DETECTION FOR TIMING ACQUSITION IN WIRELESS COMMUNICATIONS

CLAIM OF PRIORITY UNDER35 U.S.C. §119

The present Application for Patent claims priority to PCT International Application No. PCT/CN2014/084688 entitled “Gap Detection for Timing Acquisition at a User Equipment (UE) in a TD-SCDMA Network” filed August 19, 2014, which is assigned to the assignee hereof and hereby expressly incorporated by reference herein.

BACKGROUND

Aspects described herein relate generally to communication systems, and more particularly, to timing acquisition in wireless networks.

Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasts. Typical wireless communication systems may employ multiple-access technologies capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power) . Examples of such multiple-access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single-carrier frequency division multiple access (SC-FDMA) systems, and time division synchronous code division multiple access (TD-SCDMA) systems.

These multiple-access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate on a municipal, national, regional, and even global level. An example of a telecommunication standard is Long Term Evolution (LTE) . LTE is a set of enhancements to the Universal Mobile Telecommunications System (UMTS) mobile standard promulgated by Third Generation Partnership Project (3GPP) . Generally, a wireless multiple-access communication system can simultaneously support communication for multiple wireless terminals (e.g., user equipment (UE) ) , each of which can communicate with one or more base stations over downlink or uplink resources.

For example, gap detection may be performed by a UE at the beginning of TD-SCDMA timing acquisition. The purpose of gap detection is to identify a high-low-high-low (HLHL) energy pattern between timeslot 0 (TS0) and downlink pilot timeslot (DwPTS) time slots which is unique to a sub-frame of a TD-SCDMA signal. However, in some cases, a frequency band may be allocated to either a TD-SCDMA system or an LTE system. When an LTE signal received over such a frequency band is detected in TD-SCDMA gap detection, the TD-SCDMA gap detection should return an invalid search result and the acquisition should stop. But, in some instances, the TD-SCDMA acquisition may falsely obtain a valid search result (e.g., for an LTE signal) in gap detection, and waste time and resources in the following steps of acquisition.

Therefore, it may be desired to identify false alarms in gap detection caused by LTE signals.

SUMMARY

The following presents a simplified summary of one or more aspects in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated aspects, and is intended to neither identify key or critical elements of all aspects nor delineate the scope of any or all aspects. 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.

According to an example, a method of performing gap detection for a timing acquisition in a wireless network is provided. The method includes performing a gap detection for identifying a gap position in a signal received in a frequency band, determining a gap detection metric for the gap position identified by the gap detection, and determining whether the signal is associated with a first radio access technology. Determining whether the signal is associated with the first radio access technology may be based at least in part on determining whether the gap detection metric achieves a first threshold value, and performing one or more validating checks to further validate whether the signal is associated with the first radio access technology.

In another example, an apparatus for performing gap detection for a timing acquisition in a wireless network is provided. The apparatus includes a gap position identifying component configured to perform a gap detection for identifying a gap position in a signal received in a frequency band, a gap detection metric determining component configured to determine a gap detection metric for the gap position identified by the gap detection, a determining component configured to determine whether the gap detection metric achieves a first threshold value in determining whether the signal is associated with a first radio access technology, and a validating component configured to perform one or more validating checks of the signal in determining whether the signal is associated with the first radio access technology.

Further, in an example, an apparatus for performing gap detection for a timing acquisition in a wireless network is provided. The apparatus includes means for performing a gap detection for identifying a gap position in a signal received in a frequency band, means for determining a gap detection metric for the gap position identified by the gap detection, means for determining whether the gap detection metric achieves a first threshold value in determining whether the signal is associated with a first radio access technology, and means for performing one or more validating checks of the signal in determining whether the signal is associated with the first radio access technology.

In a further example, a computer-readable medium for performing gap detection for a timing acquisition in a wireless network is provided. The computer-readable medium includes code for performing a gap detection for identifying a gap position in a signal received in a frequency band, code for determining a gap detection metric for the gap position identified by the gap detection, code for determining whether the gap detection metric achieves a first threshold value in determining whether the signal is associated with a first radio access technology, and code for performing one or more validating checks of the signal in determining whether the signal is associated with the first radio access technology.

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 an example of a frame structure in a time division synchronous code division multiple access (TD-SCDMA) system；

Fig. 2 is a block diagram illustrating an example high-low-high-low (HLHL) energy pattern in a telecommunications system；

Figs. 3A-3D are block diagrams illustrating examples of signals of other radio access technologies received in an example TD-SCDMA system；

Fig. 4 is a block diagram illustrating an example wireless system in accordance with aspects described herein；

Fig. 5 is a flow diagram illustrating aspects of an example methodology in accordance with aspects described herein；

Fig. 6 is a flow diagram illustrating aspects of an example methodology for performing validation checks in accordance with aspects described herein；

Fig. 7 is a flow diagram illustrating aspects of an example methodology for performing validation checks in accordance with aspects described herein；

Fig. 8 is a flow diagram illustrating aspects of an example methodology for performing validation checks in accordance with aspects described herein；

Fig. 9 is a block diagram illustrating aspects of a computer device in accordance with aspects described herein；

Fig. 10 is a conceptual diagram illustrating an example of an access network； and

Fig. 11 is a block diagram conceptually illustrating an example of a NodeB 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 are shown in block diagram form in order to avoid obscuring such concepts.

Several aspects of telecommunication systems will now be presented with reference to various apparatus and methods. These apparatus and methods will be described in the following detailed description and illustrated in the accompanying drawings by various blocks, modules, components, circuits, steps, processes, algorithms, etc. (collectively referred to as “elements” ) . These elements may be implemented using electronic hardware, computer software, or any combination thereof. Whether such elements are implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. In an aspect, a component may be one of the parts that make up a system, may be hardware or software, and may be divided into other components.

By way of example, 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 herein. 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.

Accordingly, in one or more example embodiments, the functions described may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored on or encoded as one or more instructions or code on a computer-readable medium. Computer-readable media includes computer storage media. Storage media may be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can comprise a random-access memory (RAM) , a read-only memory (ROM) , an electrically erasable programmable ROM (EEPROM) , compact disk ROM (CD-ROM) or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. Combinations of the above should also be included within the scope of computer-readable media.

Described herein are aspects related to performing gap detection as part of acquiring timing in a wireless network. Gap detection allows for identifying gaps in received signals indicative of a recognizable signal pattern to determine that the signal relates to a radio access technology used by the wireless network (e.g., as opposed to other radio access technologies used by surrounding wireless networks) . In some gap detection implementations, a positioning of gaps within a signal can be determined based on testing a plurality of gap position hypotheses, as further described herein. A gap detection metric for each gap position hypothesis is compared to a threshold to determine potential validity of the gap position hypothesis. In an example, for a valid gap position hypothesis, one or more additional validation checks can be performed on the signal to ensure the determination of the signal as being valid based on the gap detection metric is not a false positive determination. The following aspects are discussed with respect to determining whether a received signal is a time division synchronous code division multiple access (TD-SCDMA) signal in specific examples； however, this is just one example implementation and the aspects discussed herein may be similarly applied to determine if a received signal is a different radio access technology type signal (e.g., where applicable, such as when a recognizable signal pattern may be associated with a different radio access technology type signal) .

Fig. 1 shows a frame structure 100 for a TD-SCDMA carrier. For example, the TD-SCDMA carrier, as illustrated, has a frame 102 that is 10 milliseconds (ms) in length. The frame 102 has two 5 ms sub-frames 104, and each of the sub-frames 104 includes seven time slots, TS0 through TS6. The first time slot, TS0, is usually allocated for downlink communication, while the second time slot, TS1, is usually allocated for uplink communication. The remaining time slots, TS2 through TS6, may be used for either uplink or downlink, which allows for greater flexibility during times of higher data transmission times in either the uplink or downlink directions.

In an aspect, a Downlink Pilot Time Slot (DwPTS) 106 (also known as the Downlink Pilot Channel (DwPCH) ) , a guard period (GP) 108, and an Uplink Pilot Time Slot (UpPTS) 110 (also known as the uplink pilot channel (UpPCH) ) are located between TS0 and TS1. The Downlink Pilot Time Slot 106 is 96 chips (75 microseconds (μs) ) in length. The guard period 108 is 96 chips (75 μs) in length. The Uplink Pilot Time Slot 110 is 160 chips (125 μs) in length.

In an aspect, the Downlink Pilot Time Slot 106 includes a guard period 118 and a synchronization downlink (SYNC-DL) sequence 120. The guard period 118 is 32 chips (25 μs) in length. The SYNC-DL sequence 120 is 64 chips (50 μs) in length. Each time slot, TS0-TS6, may allow data transmission multiplexed on a maximum of 16 code channels. Each time slot TS0-TS6 is 675 μs in length. Data transmission on a code channel includes two data portions 112 separated by a midamble 114 and followed by a Guard Period (GP) 116. The midamble 114 may be used for features, such as channel estimation, while GP 116 may be used to avoid inter-burst interference.

In an aspect, there are a number of situations when a user equipment may attempt to acquire a signal, including during power-on, wake up, etc. When a user equipment attempts to locate a signal in a TD-SCDMA network on a certain frequency band, the user equipment does not know whether any cell is actually transmitting on that band, nor any timing associated with such transmissions. In TD-SCDMA, to help during this acquisition stage, each base station transmits the same pilot signal at every sub-frame (i.e., every 6400 chips ＝ 5 milliseconds (ms) ) . Different base stations may use different pilot signals in the downlink pilot time slot. Each pilot signal identifies the base station from which it was sent. These signals are known as synchronization downlink (SYNC-DL) sequences. There are 32 different SYNC-DL sequences, each is 64-chips (50 microseconds (μs) ) long.

In an aspect, for example, correlation-based algorithms may be used in the acquisition stage. Such example correlation-based algorithms may involve computing a correlation between each SYNC-DL sequence possibly transmitted, and each 64-chip window of received samples possibly aligned to the SYNC-DL sequence. Because no timing reference is yet available at this stage, all 64-chip windows in an interval of 5 ms (i.e., the repetition period for the pilot signal) may be equally likely. Each sub-frame 104, as shown in Fig. 1, is 6,400 chips in length. This results in the testing of 6,400 potential windows (5 ms *1.28 Mcps, mega chips per second) if the target granularity for timing acquisition is one chip.

Fig. 2 is a block diagram illustrating an example HLHL energy pattern 200 in a telecommunications system；

In an aspect, as part of TD-SCDMA communications, a first time slot in a sub-frame, called time slot zero (TS0) 202, and the SYNC-DL field 206 can be transmitted with similar power and separated by a silent guard period 204 of 48 chips, 16 chips at the end of TS0 and 32 chips as part of a guard period 208 at the beginning of the SYNC-DL field 206. The SYNC-DL field 206 and the following UpPTS 210 are also separated by a guard period 208 of 96 chips. This sequence of TS0, guard, SYNC-DL field, guard, makes up a high-low-high-low (HLHL) power pattern characterized by a detected period of high power/energy “H” (also referred to herein as a high energy zone) , followed by a detected period of low power/energy “L” (also referred to herein as a low energy zone) , followed by another detected period of high power/energy “H” , followed by another detected period of low power/energy “L. ” The first period of low power/energy can have a duration of 48 chips, corresponding to a GP 204, and the second period of high power/energy can have a duration of 64 chips, corresponding to a SYNC-DL field 206, etc. This particular HLHL power pattern is characteristic of a TD-SCDMA sub-frame. Because TD-SCDMA communications are synchronous, the pattern is preserved even in the presence of interfering cells. The particular HLHL pattern may be specifically detected as described below to improve timing acquisition.

Figs. 3A-3D are block diagrams illustrating examples of signals of other radio access technologies received in an example TD-SCDMA system. For example, as described further herein, signals of other radio access technologies may be received over frequency bands utilized in the TD-SCDMA system. It is possible that these signals exhibit characteristics of the HLHL pattern, and may be thus improperly detected as TD-SCDMA signals in a gap detection procedure.

For example, in an aspect, Fig. 3A illustrates an example third generation partnership project (3GPP) long term evolution (LTE) signal 300. Signal 300 includes one inactive orthogonal frequency division multiplexing (OFDM) symbol between two active OFDM symbols. In LTE, given a 1 ms sub-frame and a sub-frame length of 14 symbols, each OFDM symbol can be 1 ms /14, which is approximately 714 μs. In TD-SCDMA, this can correspond to around 91 chips. Mechanisms for performing gap detection are described further herein, but it is possible that performing TD-SCDMA gap detection on LTE signal 300 may result in improperly determining that the LTE signal 300 is a TD-SCDMA signal, based on average energy values of a given gap detection hypothesis over the signal 300. For example, the active OFDM symbols may be mistakenly interpreted as corresponding to period of high signal power/energy in a TD-SCDMA signal, and the inactive OFDM symbol may be mistakenly interpreted as corresponding to a period of low signal power/energy in a TD-SCDMA signal.

In an additional aspect, for example, Fig. 3B illustrates another example LTE signal 302 having an active OFDM symbol, an inactive OFDM symbol, and a high spike in signal energy. Similarly, in this example, performing TD-SCDMA gap detection on LTE signal 302 may result in improperly determining that the LTE signal 302 is a TD-SCDMA signal, based on average energy values of a given gap detection hypothesis over the signal 302. For example, the active OFDM symbol and the high spike may be mistakenly interpreted as corresponding to period of high signal power/energy in a TD-SCDMA signal, and the inactive OFDM symbol may be mistakenly interpreted as corresponding to a period of low signal power/energy in a TD-SCDMA signal.

In an additional aspect, for example, Fig. 3C illustrates another example LTE signal 304 having an active OFDM symbol, and inactive OFDM symbols with high spikes in signal energy. Similarly, in this example, performing TD-SCDMA gap detection on LTE signal 304 may result in improperly determining that the LTE signal 304 is a TD-SCDMA signal, based on average energy values of a given gap detection hypothesis over the signal 304. For example, the active OFDM symbol and one or more of the high spikes may be mistakenly interpreted as corresponding to period of high signal power/energy in a TD-SCDMA signal, and the inactive OFDM symbols may be mistakenly interpreted as corresponding to a period of low signal power/energy in a TD-SCDMA signal.

In an additional aspect, for example, Fig. 3D illustrates another example LTE signal 306 having active OFDM symbols with high spikes in signal energy, and inactive OFDM symbols. Similarly, in this example, performing TD-SCDMA gap detection on LTE signal 306 may result in improperly determining that the LTE signal 306 is a TD-SCDMA signal, based on average energy values of a given gap detection hypothesis over the signal 306. For example, the high spikes may be mistakenly interpreted as corresponding to period of high signal power/energy in a TD-SCDMA signal, and the remainder of the active OFDM symbols and/or inactive OFDM symbols may be mistakenly interpreted as corresponding to a period of low signal power/energy in a TD-SCDMA signal.

Referring to Fig. 4, a wireless communication system 400 is illustrated that facilitates performing gap detection for a timing acquisition in a wireless network. For example, in an aspect, for example, system 400 may include network entity 410 and/or base station 420 for providing over-the-air service to UE 402. Further, UE 402 may communicate with network entity 410 and/or base station 420 over one or more links 422 and/or 424 for various functions, e.g., configuration, monitoring, management, etc.

In an aspect, network entity 410 may include, but not be limited to, an access point, a base station (BS) or Node B or eNodeB, a macro cell, a small cell (e.g., a femtocell, or a pico cell) , a relay, a peer-to-peer device, an authentication, authorization and accounting (AAA) server, a mobile switching center (MSC) , Mobility Management Entity (MME) , SON management server, OAM server, Home NodeB Management System (HMS) , Home eNodeB Management System (HeMS) , etc. Additionally, network entity 410 may include one or more of any type of network components that can enable base station 420 to communicate and/or establish and maintain links 422 and/or 424 with network entity 410. In an example aspect, base station 420 may operate according to TD-SCDMA as defined in 3GPP Specifications.

In an additional aspect, UE 402 may be a mobile apparatus and 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.

For example, in some cases, a frequency band may be allocated to either a TD-SCDMA system or an LTE system. In such cases, performing gap detection on received signals for TD-SCDMA can return an invalid search result for LTE signals, and the timing acquisition at the UE should stop. As described above, however, there may be instances where the gap detection performed during the timing acquisition (e.g., TD-SCDMA timing acquisition at the UE) may falsely (e.g., incorrectly) obtain a valid search result (e.g., that the signal is associated with TD-SCDMA) in gap detection and proceed with the TD-SCDMA timing acquisition. In this case, the TD-SCDMA timing acquisition may ultimately fail, thus wasting valuable time and resources. Therefore, it can be desirable to identify cases of false positives (or false alarms) in gap detection caused by LTE signals.

In an aspect, UE 402 may include a gap detection manager 404 for performing gap detection to determine whether a received signal relates to a given radio access technology. For example, gap detection manager 404 can include a gap position identifying component 430 for identifying a gap position in a signal received in a frequency band, a gap detection metric determining component 432 for determining a gap detection metric for the gap position, a determining component 434 for determining whether the highest gap detection metric is greater than a first threshold value, and a validating component 436 for performing one or more validating checks to further validate whether the signal is associated with the first radio access technology.

Fig. 5 illustrates an example methodology 500 for gap detection during a timing acquisition in a wireless network.

In an aspect, at block 510, methodology 500 may include performing a gap detection for identifying a gap position in a signal received in a frequency band. For example, gap position identifying component 430 can perform the gap detection for identifying the gap position in a signal received in a frequency band.

For example, in an aspect, UE 402 and/or gap detection manager 404 may perform gap detection (e.g., initiate a gap detection mechanism) for timing acquisition at the UE. In an aspect specific to TD-SCDMA, gap detection may be performed to identify high-low-high-low (HLHL) energy pattern as shown, for example, in Fig. 2 above, as the HLHL energy pattern is unique to a sub-frame of a TD-SCDMA signal. It is to be appreciated, however, that gap detection manager 404 can similarly detect gap patterns characteristic of signals of other radio access technologies to determine whether received signals relate to the other radio access technologies. In an aspect, a gap detection mechanism may be performed for a signal received in a frequency band. The frequency band, and thus received signal, in one example, may be associated with TD-SCDMA or an LTE.

In an aspect, for example in TD-SCDMA, gap detection can be performed at the beginning of TD-SCDMA timing acquisition. The purpose of gap detection is to identify the HLHL energy pattern of a received signal between TS0 and UpPTS, as described with reference to Figs. 1 and 2. The HLHL energy pattern is a characteristic of a sub-frame of TD-SCDMA signals, and can thus be used to identify signals as relating to TD-SCDMA communications. Gap detection manager 404 can accordingly perform gap detection over a received signal, which can include gap position identifying component 430 identifying a gap position associated with the gaps that identify each of the HLHL energy patterns. For example, a gap can refer to a given period of high or low signal power/energy (also referred to herein as a zone) in the signal. The gap position can refer specifically to the determined start of the first guard period (e.g., guard period 204) after the first time slot (e.g., TS0 202) , where such can be determined based on aspects described herein.

In an aspect, there can be around 6400 hypotheses of the gap position, corresponding to 6400 chips in a given TD-SCDMA sub-frame. For each hypothesis, gap position identifying component 430 can estimate four average energy values, corresponding to the 4 periods of HLHL. In an aspect, for example, the average energy values may be denoted as Q₀, Q₁, Q₂, and Q₃ for H, L, H, and L energy zones respectively. For gap position identifying component 430 to determine a hypothesis that matches the true gap position, Q₀ and Q₂ are supposed to be higher than Q₁ and Q₃. Based on Q₀, Q₁, Q₂, and Q₃, gap position identifying component 430 can compute a metric of perceivability, denoted as M and also referred to herein as a gap detection metric, for each hypothesis. For example, if M achieves a threshold, gap detection manager 404 can determine that the signal corresponds to a TD-SCDMA signal； however, other validation checks can be considered as well, as described below.

In an aspect, to estimate Q₀, Q₁, Q₂, and Q₃, gap position identifying component 430 may consider samples of different lengths, where the length of each sample can match a length of a corresponding gap. In one specific example, to estimate Q_i (i ＝ 0 to 3) , gap position identifying component 430 can determine a specified starting point for sample energy accumulation and length of samples, which are denoted as A_i herein. For example, if x (n) , n＝0 to 6400 is represented as the received samples, then

In an aspect, for example, A₁＝48, A₂＝64 and A₃＝96 to match the chip length of the gaps. A₀ may be set to substantially any value (e.g., A₀＝96) . The starting point of each gap is thus s₀＝k-A₀, s₁＝k, s₂＝k+A₁ and s₃＝k+A₁+A₂, where k represents the start of the first guard period (e.g., guard period 204) , and thus also represents the gap position, as described. In an additional aspect, gap position identifying component 430 may adjust A_i and s_i by several chips to account for possible energy leakage during the transition step.

As described, for example, gap position identifying component 430 can estimate the average energy values Q₀, Q₁, Q₂, and Q₃ for one or more of the 6400 possible gap position hypotheses. For each gap position hypothesis for which gap position identifying component 430 estimates the average energy values, gap position identifying component 430 can compute the perceivability metric M (also referred to herein as the gap detection metric) , and determine which gap position hypothesis has the highest value for M. Thus, for example, performing the gap detection at block 510 may include, at block 520, identifying a gap position in a plurality of gap position hypotheses as having a highest gap detection metric. Therefore, in an example, gap position identifying component 430 can identify the gap position in the plurality of gap position hypotheses as having the highest gap detection metric, M, in performing the gap detection. In one specific example, gap position identifying component 430 can compute:

M ＝ min (Q₀, Q₂) –max (Q₁, Q₃)

More generally, performing the gap detection at block 510 can include, at block 530, determining a gap detection metric for the gap position detected by the gap detection. Gap detection metric determining component 432 can determine the gap detection metric for the gap position detected by the gap detection. For example, the gap detection can detect the gap position hypothesis with the highest gap detection metric as the gap position, as described, and thus gap detection metric determining component 432 can determine the gap detection metric of this gap position based on the performed gap detection.

Methodology 500 can also include, at block 540, determining whether the signal is associated with a first radio access technology. Determining component 434 and/or validating component 436 can determine whether the signal is associated with the first radio access technology, as described herein. For example, this can be based on one or more considerations regarding the gap detection metric and/or other validation checks of the signal.

For example, determining whether the signal is associated with the first radio access technology at block 540 can include, at block 550, determining whether the gap detection metric achieves a first threshold value. Determining component 434 can determine whether the gap detection metric achieves the first threshold value. If so, in one example, block 560 can also be performed. If the gap detection metric (e.g., the highest gap detection metric of the gap position hypotheses, as described above) does not achieve the first threshold value, however, determining component 434 can determine that the signal is not associated with the first radio access technology. In addition, in this case, gap detection manager 404 can stop the timing acquisition procedure related to the gap detection. It is possible, however, that signals of other radio access technologies can exhibit properties that result in a determined gap position with a gap detection metric that achieves the threshold, examples of which are described above with reference to Figs. 3A-3D. Accordingly, validating component 436 can validate one or more other aspects of a received signal to determine whether the received signal is associated with the first radio access technology.

Thus, determining whether the signal is associated with the first radio access technology at block 540 may include, at block 560, performing one or more validation checks to further validate whether the signal is associated with the first radio access technology. Validating component 436 can perform the one or more validation checks to further validate whether the signal is associated with the first radio access technology. Similarly, if the one or more validation checks pass, validating component 436 can confirm that the signal is associated with the first radio access technology, but if the one or more validation checks fail, validating component 436 can determine that the signal is not associated with the first radio access technology and timing acquisition can be stopped. Examples of one or more possible validation checks that may be performed at block 560 are further described with reference to Figs. 6-8.

In one example, one or more validation checks may be based on comparing estimated energy values to a threshold. Thus, performing the one or more validation checks at block 560 may optionally include, at block 570, determining whether a function of one or more estimated average energy values of the signal determined based on the gap position achieve a second threshold value indicating that the signal is not associated with the first radio access technology. Validating component 436 can determine whether the function of the one or more estimated average energy values of the signal determined based on the gap position achieve the second threshold value indicating that the signal is not associated with the first radio access technology. As described, the estimated energy values may correspond to one or more of Q₀, Q₁, Q₂, and Q₃ above. In addition, for example, the second threshold value may correspond to the threshold applied to one or more of the average energy values as well, as described further herein.

For example, Fig. 6 illustrates an example methodology 600 for performing one or more validation checks on a received signal. Methodology 600 includes, at block 560, performing one or more validation checks to further validate whether the signal is associated with the first radio access technology, as described. For example, block 560 may optionally include, at block 610, determining energy values of a first high energy zone and a second high energy zone. For example, validating component 436 can determine the energy values of the first high energy zone and the second high energy zone. This may include, for example, determining Q₀ and Q₂ for the determined gap position. The values of Q₀ and Q₂ may have already been computed by gap position identifying component 430, and as such, validating component 436 may determine these values from the gap position identifying component 430, in one example. In another example, however, validating component 436 may compute these values using the formulas described herein for the determined gap position.

Block 560 may also optionally include, at block 620, determining whether the signal is associated with the first radio access technology based on whether the energy value of the first high energy zone is greater than the energy value of the second high energy zone multiplied by a second threshold value. Validating component 436 can determine whether the signal is associated with the first radio access technology based on whether the energy value of the first high energy zone is greater than the energy value of the second high energy zone multiplied by the second threshold value. Thus, for example, this first validation check, can be represented by, for example, determining whether Q₀ > TH_MAX_Q_DIFF *Q₂, where TX_MAX_Q_DIFF can be the second threshold value. In this example, where Q₀ > TH_MAX_Q_DIFF *Q₂, validating component 436 may determine that the signal does not relate to the first radio access technology (e.g., TD-SCDMA) , and thus, in one example, and this first validation check fails. Accordingly. the timing acquisition may be stopped as well. Otherwise, the first validation check may pass.

The second threshold value, TH_MAX_Q_DIFF, may be configured by the validating component 436 (e.g., based on a received configuration, a stored value, etc. ) to a value (e.g., a value around 3-5) . This first validation check is based on the differences in energy levels between TS0 and DwPTS as the energy value of TS0 is typically lower than the energy value of DwPTS. For example, in an aspect, this first validation check may apply for a case where a first H (e.g., high energy zone) is from an active OFDM symbol in an LTE signal and is followed by a second H (e.g., high energy zone) , where the second H is due to a high spike in the following inactive OFDM symbols (e.g., as shown in FIG. 3B) .

In another aspect, for example, block 560 may optionally include, at block 630, determining energy level values of a first low energy zone and a second low energy zone. For example, validating component 436 can determine the energy values of the first low energy zone and the second low energy zone. This may include, for example, determining Q₁ and Q₃ for the determined gap position. The values of Q₁ and Q₃ may have already been computed by gap position identifying component 430, and as such, validating component 436 may determine these values from the gap position identifying component 430, in one example. In another example, however, validating component 436 may compute these values using the formulas described herein for the determined gap position.

Block 560 may also optionally include, in this example at block 640, identifying a lowest energy value between the energy value of the first low energy zone and the second low energy zone. For example, validating component 436 can identify the lowest energy value between the energy value of the first low energy zone and the second low energy zone. Moreover, for example, block 560 may also optionally include, at block 650, determining whether the signal is associated with the first radio access technology based on whether the lowest energy value is greater than a global minimum energy value multiplied by a third threshold value. Validating component 436 can determine whether the signal is associated with the first radio access technology based on whether the lowest energy value is greater than the global minimum energy value multiplied by a third threshold value.

Thus, this second validation check can be represented by determining whether min (Q₁, Q₃) > TH_MIN_Q *Min_Q₁Q₃_Global, where TH_MIN_Q is the third threshold value, and Min_Q₁Q₃_Global is the global minimum energy value. In an example, Min_Q₁Q₃_Global can be defined as the minimum of min (Q₁, Q₃) for all gap position hypotheses. This may validate that the two low energies of the best hypothesis, Q₁ and Q₃, are contributed by noises. In this example, where min (Q₁, Q₃) > TH_MIN_Q *Min_Q₁Q₃_Global, validating component 436 may determine that the signal does not relate to the first radio access technology (e.g., TD-SCDMA) , and this second validation check may fail. Accordingly, in one example, the timing acquisition may be stopped as well. Otherwise, the second validation check may pass.

The third threshold value, TH_MIN_Q, may be configured by the validating component 436 (e.g., based on a received configuration, a stored value, etc. ) . For example, in an aspect, this second validation check may apply where the minimum of the two low energy zones (e.g., Q₁ and Q₃) , associated with the determined gap position hypothesis is greater than the global minimum low energy at least by a threshold value (e.g., third threshold value) . In this case, validating component 436 can determine that the signal is not associated with the first radio access technology (e.g., a TD-SCDMA) . For example, in an aspect, the second validation check may apply where two Hs (e.g., high energy zones) are associated with narrow high spikes in an active OFDM symbol of an LTE signal (e.g., as shown in Fig. 3D) .

Fig. 7 illustrates an additional example methodology 700 for performing one or more validation checks on a received signal. Methodology 700 includes, at block 560, performing one or more validation checks to further validate whether the signal is associated with the first radio access technology, as described. For example, block 560 may optionally include, at block 710, determining first energy values of a first high energy zone and a second high energy zone at a first starting index. For example, validating component 436 can determine the first energy values of the first high energy zone and the second high energy zone at the first starting index. This may include, for example, determining Q₀ and Q₂ for the determined gap position, which may be offset based on the first starting index. The values of Q₀ and Q₂ may have already been computed by gap position identifying component 430, and as such, validating component 436 may determine these values from the gap position identifying component 430, in one example. In another example, however, validating component 436 may compute these values using the formulas described herein for the determined gap position. In one specific example, validating component 436 can determine the values for Q₀ and Q₂ for k₀, [s₀ s₁ s₂ s₃] ＝ [-40 0 56 48+64] , and [A₀ A₁ A₂ A₃] ＝ [24 24 24 24] .

Block 560 may optionally include, at block 720, determining second energy values of the first high energy zone and the second high energy zone at a second starting index. For example, validating component 436 can determine the first energy values of the first high energy zone and the second high energy zone at the second starting index. This may include, for example, determining Q₀ and Q₂ for the determined gap position, which may be offset based on the second starting index (e.g., Q₀' and Q₂') . The values of Q₀' and Q₂' may have already been computed by gap position identifying component 430, and as such, validating component 436 may determine these values from the gap position identifying component 430, in one example. In another example, however, validating component 436 may compute these values using the formulas described herein for the determined gap position. In one specific example, validating component 436 can determine the values for Q₀' and Q₂' for k₀, [s₀ s₁ s₂ s₃] ＝ [-64 0 80 48+64] , and [A₀ A₁ A₂ A₃] ＝ [24 24 24 24] .

Block 560 may also optionally include, at Block 730, identifying a lowest energy value between the first energy values and the second energy values. Validating component 436 can identify the lowest energy value between the first energy values and the second energy values (e.g., min (Q₀, Q₂, Q₀', Q₂') ) .

Block 560 may also optionally include, at Block 740, identifying a highest energy value between energy values of a first low energy zone and a second low energy zone at the first starting index. For example, validating component 436 can determine the energy values of the first low zone and the second low energy zone at the first starting index, and may accordingly identify a highest energy value between energy values. This may include, for example, determining Q₁ and Q₃ for the determined gap position, which may be offset based on the first starting index, and identifying max (Q₁, Q₃) . The values of Q₁ and Q₃ may have already been computed by gap position identifying component 430, and as such, validating component 436 may determine these values from the gap position identifying component 430, in one example. In another example, however, validating component 436 may compute these values using the formulas described herein for the determined gap position. In one specific example, validating component 436 can determine the values for Q₁ and Q₃ for k₀, [s₀ s₁ s₂ s₃] ＝ [-40 0 56 48+64] , and [A₀ A₁ A₂ A₃] ＝ [24 24 24 24] .

Block 560 can also optionally include, at block 750, determining whether the signal is associated with the first radio access technology based on whether the lowest energy value is less than the highest energy value multiplied by a fourth threshold value. Validating component 436, for example, can determine whether the signal is associated with the first radio access technology based on whether the lowest energy value is less than the highest energy value multiplied by a fourth threshold value. Thus, this third validation check can be represented by, for example, determining whether min (Q₀, Q₂, Q₀', Q₂') < TH_NARROW_GAP *max (Q₁, Q₃) , where TH_NARROW_GAP is the fourth threshold value. In this example, where min (Q₀, Q₂, Q₀', Q₂') < TH_NARROW_GAP *max (Q₁, Q₃) , validating component 436 may determine that the signal does not relate to the first radio access technology (e.g., TD-SCDMA) , and this third validation check may fail. Accordingly, in one example, the timing acquisition may be stopped as well. Otherwise, the third validation check may pass.

The fourth threshold value, TH_NARROW_GAP, may be configured by the validating component 436 (e.g., based on a received configuration, a stored value, etc. ) . In a specific example in TD-SCDMA, at a good signal-to-noise level, unless the HLHL energy pattern is well-matched to the TD-SCDMA signal, the four high energy values, Q₀, Q₀’, Q₂, and Q₂’, may not always be significantly higher than the low energy values Q₁, Q₃. In this way, a TD-SCDMA signal may be better differentiated from an LTE signal. In an aspect, this third validation check may apply where one inactive OFDM symbol is between two active OFDM symbols in an LTE signal (e.g., as shown in Fig 3A) .

Fig. 8 illustrates an example methodology 800 for performing one or more validation checks on a received signal. Methodology 800 includes, at block 560, performing one or more validation checks to further validate whether the signal is associated with the first radio access technology, as described. For example, block 560 may optionally include, at block 810, computing average energy values during a plurality of consecutive energies. Validating component 436 can compute the average energy values during the plurality of consecutive energies. In a specific example, for k ＝ k₀-T (k≥0) , validating component 436 can compute average energy over 24 consecutive chip energies, e.g.,

In an example, validating component 436 may compute the chip energies over multiple values of T (e.g., 64, 128, 192, 256, etc. ) . In other words, for the selected gap position hypothesis k₀, a check is performed to determine whether there are extraordinarily high spikes in the first high energy segment. For example, the average energies between k₀–T and k₀–T + D for several T values can be computed.

Additionally, block 560 may optionally include, at block 820, identifying a highest energy value between energy values for a fist high energy zone and a second high energy zone. Validating component 436 may identify the highest energy value between energy values for the fist high energy zone and the second high energy zone. This may include, for example, determining Q₀ and Q₂ for the determined gap position, which may be offset based on the first starting index, and identifying max (Q₀, Q₂) . The values of Q₀ and Q₂ may have already been computed by gap position identifying component 430, and as such, validating component 436 may determine these values from the gap position identifying component 430, in one example. In another example, however, validating component 436 may compute these values using the formulas described herein for the determined gap position.

Block 560 may also optionally include, for example, determining whether the signal is associated with the first radio access technology based on whether at least one of the average energy values is greater than the highest energy value multiplied by a fifth threshold value. Validating component 436 can determine whether the signal is associated with the first radio access technology based on whether at least one of the average energy values is greater than the highest energy value multiplied by a fifth threshold value. Thus, this fourth validation check can be represented by determining whether s > TH_ON_SYMBOL *max (Q₀, Q₂) , where TH_ON_SYMBOL is the fifth threshold. In this example, where s >TH_ON_SYMBOL *max (Q₀, Q₂) , validating component 436 may determine that the signal does not relate to the first radio access technology (e.g., TD-SCDMA) , and this fourth validation check may fail. Accordingly, in one example, the timing acquisition may be stopped as well. Otherwise, the fourth validation check may pass.

The fifth threshold value, TH_ON_SYMBOL, may be configured by the validating component 436 (e.g., based on a received configuration, a stored value, etc. ) . For example, in a TD-SCDMA signal, the first high energy segment is associated with TS₀, and therefore the average energy between k₀–T and k₀–T+ D should be comparable to Q₀ and Q₂. If it is not, then it may be more likely the signal is an LTE signal in which an OFDM symbol is possibly followed by a high spike. For example, in an aspect, this fourth validation check may apply where an active OFDM symbol is followed by high spikes in inactive OFDM symbols (e.g., as shown in Figs 3B and 3C) .

In an additional aspect, block 560 may optionally include, at block 840, identifying a highest sample energy value contributing to an energy value of a first high energy zone or a second high energy zone. For example, validating component 436 can identify the highest sample energy value contributing to the energy value of the first high energy zone or the second high energy zone. For example, this can include determining P₀＝ max {x² (n) } for n＝ (k₀-s₀) to (k₀-s₀ +A₀-1) and/or P₂＝ max {x² (n) } for n＝ (k₂-s₂) to (k₂-s₂+A₂-1) .

Block 560 may also optionally include, at block 850, determining whether the signal is associated with the first radio access technology based on whether the highest sample energy value contributing to the energy value of the first high energy zone is greater than the energy value of the first high energy zone multiplied by a sixth threshold value. Validating component 436 can determine whether the signal is associated with the first radio access technology based on whether the highest sample energy value contributing to the energy value of the first high energy zone is greater than the energy value of the first high energy zone multiplied by the sixth threshold value.

Similarly, block 560 may also optionally include, at block 850, determining whether the signal is associated with the first radio access technology based on whether the highest sample energy value contributing to the energy value of the second high energy zone is greater than the energy value of the second high energy zone multiplied by the sixth threshold value. Validating component 436 can determine whether the signal is associated with the first radio access technology based on whether the highest sample energy value contributing to the energy value of the second high energy zone is greater than the energy value of the second high energy zone multiplied by the sixth threshold value. Thus, this fifth validation check can be represented by determining whether P₀ > TH_PAPR *Q₀ or P₂ >TH_PAPR *Q₂, ) , where TH_PAPR is the sixth threshold. In this example, where P₀ > TH_PAPR *Q₀ or P₂ > TH_PAPR *Q₂, ) , validating component 436 may determine that the signal does not relate to the first radio access technology (e.g., TD-SCDMA) , and this fifth validation check may fail. Accordingly, in one example, the timing acquisition may be stopped as well. Otherwise, the fifth validation check may pass.

The sixth threshold value, TH_PAPR, may be configured by the validating component 436 (e.g., based on a received configuration, a stored value, etc. ) . TH_PAPR can be configured as a larger value (e.g., 10) . For example, this fifth validation check may apply where narrow high spikes contribute to the first of the second high energy in the HLHL energy pattern (e.g., as shown in Figs 3B and 3C) .

As described above, gap detection at a user equipment (UE) for a timing acquisition in a time division synchronous code division multiple access (TD-SCDMA) network may be achieved not only based on the gap detection metric, but also based on one or more of the validation checks described above. It is to be appreciated that the validating component 436 may utilize one or more of the first, second, third, fourth, and/or fifth validation checks described above (or a portion thereof) , or one or more additional or alternative checks, in determining whether a signal relates to the first radio access technology.

Referring to Fig. 9, in an aspect, UE 402 and/or gap detection manager 404 (and/or one or more components thereof) may be represented by a specially programmed or configured computer device 900. In one aspect of implementation, computer device 900 may include UE 402 and gap detection manager 404 and its components, including gap position identifying component 430, gap detection metric determining component 432, determining component 434, and/or validating component 436 (Fig. 4) , such as in specially programmed computer readable instructions or code, firmware, hardware, or some combination thereof. Computer device 900 includes a processor 902 for carrying out processing functions associated with one or more of components and functions described herein. Processor 902 can include a single or multiple set of processors or multi-core processors. Moreover, processor 902 can be implemented as an integrated processing system and/or a distributed processing system.

For example, in an aspect, gap detection manager 404 may be implemented or executed using one or any combination of processor 902, memory 904, communications component 906, and/or data store 908. For example, gap detection manager 404 may be defined or otherwise programmed as one or more processor modules of processor 902. Further, for example, gap detection manager 404 may be defined as a computer-readable medium stored in memory 904 and/or data store 908 and executed by processor 902. Moreover, for example, inputs and outputs relating to operations of gap detection manager 404 may be provided or supported by communications component 906, which may provide a bus between the components of computer device 900 or an interface to communication with external devices or components. For example, gap detection manager 404 may perform gap detection as described herein for one or more signals received by communications component 906.

Computer device 900 further includes a memory 904, such as for storing data used herein and/or local versions of applications being executed by processor 902. Memory 904 can include any type of memory usable by a computer, such as random access memory (RAM) , read only memory (ROM) , tapes, magnetic discs, optical discs, volatile memory, non-volatile memory, and any combination thereof.

Further, computer device 900 includes a communications component 906 that provides for establishing and maintaining communications with one or more parties utilizing hardware, software, and services as described herein. Communications component 906 may carry communications between components on computer device 900, as well as between computer device 900 and external devices, such as devices located across a communications network and/or devices serially or locally connected to computer device 900. For example, communications component 906 may include one or more buses, and may further include transmit chain components and receive chain components associated with a transmitter and receiver, respectively, or a transceiver, operable for interfacing with external devices. In an additional aspect, communications component 906 may be configured to receive one or more pages from one or more subscriber networks. In a further aspect, such a page may correspond to the second subscription and may be received via the first technology type communication services.

Additionally, computer device 900 may further include a data store 908, which can be any suitable combination of hardware and/or software, that provides for mass storage of information, databases, and programs employed in connection with aspects described herein. For example, data store 908 may be a data repository for applications not currently being executed by processor 902 and/or any threshold values or finger position values.

Computer device 900 may additionally include a user interface component 910 operable to receive inputs from a user of computer device 900 and further operable to generate outputs for presentation to the user. User interface component 910 may include one or more input devices, including but not limited to a keyboard, a number pad, a mouse, a touch-sensitive display, a navigation key, a function key, a microphone, a voice recognition component, any other mechanism capable of receiving an input from a user, or any combination thereof. Further, user interface component 910 may include one or more output devices, including but not limited to a display, a speaker, a haptic feedback mechanism, a printer, any other mechanism capable of presenting an output to a user, or any combination thereof.

Referring to Fig. 10, an access network 1000 in a UTRAN architecture is illustrated, and may include one or more user equipment (UE) 1030, 1032, 1036, 1038, 1040, which may be configured to include a gap detection manager 404 (Fig. 4) as shown for UE 1030 in one example, for performing gap detection as described herein for one or more signals received in one or

more cells

1002, 1004, 1006. The multiple access wireless communication system includes multiple cellular regions (cells) , including

cells

1002, 1004, and 1006, each of which may include one or more sectors and which may be network entity 410 and/or base station 420 of Fig. 4. 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 1002,

antenna groups

1012, 1014, and 1016 may each correspond to a different sector. In cell 1004,

antenna groups

1018, 1020, and 1022 each correspond to a different sector. In cell 1006,

antenna groups

1024, 1026, and 1028 each correspond to a different sector. The

cells

1002, 1004 and 1006 may include several wireless communication devices, e.g., User Equipment or UEs, for example, including UE 402 of Fig. 4, which may be in communication with one or more sectors of each

cell

1002, 1004 or 1006. For example,

UEs

1030 and 1032 may be in communication with NodeB 1042,

UEs

1034 and 1036 may be in communication with NodeB 1044, and

UEs

1036 and 1040 can be in communication with NodeB 1046. Here, each

NodeB

1042, 1044, 1046 is configured to provide an access point for all the

UEs

1030, 1032, 1034, 1036, 1038, 1040 in the

respective cells

1002, 1004, and 1006. Additionally, each

NodeB

1042, 1044, 1046 may be network entity 410 and/or base station 420 of Fig. 4, and/or each

UE

1030, 1032, 1034, 1036, 1038, 1040 may be UE 402 of Fig. 4, and may perform the methods outlined herein.

As UE 1034 moves from the illustrated location in cell 1004 into cell 1006, a serving cell change (SCC) or handover may occur in which communication with the UE 1034 transitions from the cell 1004, which may be referred to as the source cell, to cell 1006, which may be referred to as the target cell. Management of the handover procedure may take place at the UE 1034, at the Node Bs corresponding to the respective cells, at an Enhanced Packet Core, or at another suitable node in the wireless network. For example, during a call with the source cell 1004, or at any other time, the UE 1034 may monitor various parameters of the source cell 1004 as well as various parameters of neighboring cells such as

cells

1006 and 1002. Further, depending on the quality of these parameters, the UE 1034 may maintain communication with one or more of the neighboring cells. During this time, the UE 1034 may maintain an Active Set, that is, a list of cells that the UE 1034 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 1034 may constitute the Active Set) . In any case, UE 1034 may execute gap detection manager 404 to perform the gap detection operations described herein.

Further, the modulation and multiple access scheme employed by the access network 1000 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. 11 is a block diagram of a NodeB 1110 in communication with UE 1150, where the NodeB 1110 may be network entity 410 and/or base station 420 and where UE 1150 may be UE 402 that may include a gap detection manager 404 (Fig. 4) for performing gap detection as described herein for one or more signals received from NodeB 1110 (e.g., by receiver 1154 and/or as processed by receive processor 1170) . Gap detection manager 404 is shown as communicatively coupled to controller/processor 1180, but it is to be appreciated that gap detecting manager 404 may be coupled to (or implemented by) controller/processor 1180 and/or one or more other processors, such as receive processor 1170, etc. In addition, as described further herein, memory 1162 may include parameters or instructions for performing functions related to gap detection manager 404 In the downlink communication, a transmit processor 1120 may receive data from a data source 1112 and control signals from a controller/processor 1140. The transmit processor 1120 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 1120 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 1144 may be used by a controller/processor 1140 to determine the coding, modulation, spreading, and/or scrambling schemes for the transmit processor 1120. These channel estimates may be derived from a reference signal transmitted by the UE 1150 or from feedback from the UE 1150. The symbols generated by the transmit processor 1120 are provided to a transmit frame processor 1130 to create a frame structure. The transmit frame processor 1130 creates this frame structure by multiplexing the symbols with information from the controller/processor 1140, resulting in a series of frames. The frames are then provided to a transmitter 1132, 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 1134. The antenna 1134 may include one or more antennas, for example, including beam steering bidirectional adaptive antenna arrays or other similar beam technologies.

At the UE 1150, a receiver 1154 receives the downlink transmission through an antenna 1152 and processes the transmission to recover the information modulated onto the carrier. The information recovered by the receiver 1154 is provided to a receive frame processor 1160, which parses each frame, and provides information from the frames to a channel processor 1184 and the data, control, and reference signals to a receive processor 1170. The receive processor 1170 then performs the inverse of the processing performed by the transmit processor 1120 in the NodeB 1110. More specifically, the receive processor 1170 descrambles and de-spreads the symbols, and then determines the most likely signal constellation points transmitted by the NodeB 1110 based on the modulation scheme. These soft decisions may be based on channel estimates computed by the channel processor 1184. The soft decisions are then decoded and de-interleaved 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 1172, which represents applications running in the UE 1150 and/or various user interfaces (e.g., display) . Control signals carried by successfully decoded frames will be provided to a controller/processor 1180. When frames are unsuccessfully decoded by the receiver processor 1170, the controller/processor 1180 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 1178 and control signals from the controller/processor 1180 are provided to a transmit processor 1179. The data source 1178 may represent applications running in the UE 1150 and various user interfaces (e.g., keyboard) . Similar to the functionality described in connection with the downlink transmission by the NodeB 1110, the transmit processor 1179 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 1184 from a reference signal transmitted by the NodeB 1110 or from feedback contained in the mid-amble transmitted by the NodeB 1110, may be used to select the appropriate coding, modulation, spreading, and/or scrambling schemes. The symbols produced by the transmit processor 1179 will be provided to a transmit frame processor 1182 to create a frame structure. The transmit frame processor 1182 creates this frame structure by multiplexing the symbols with information from the controller/processor 1180, resulting in a series of frames. The frames are then provided to a transmitter 1156, 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 1152.

The uplink transmission is processed at the NodeB 1110 in a manner similar to that described in connection with the receiver function at the UE 1150. A receiver 1135 receives the uplink transmission through the antenna 1134 and processes the transmission to recover the information modulated onto the carrier. The information recovered by the receiver 1135 is provided to a receive frame processor 1136, which parses each frame, and provides information from the frames to the channel processor 1144 and the data, control, and reference signals to a receive processor 1137. The receive processor 1137 performs the inverse of the processing performed by the transmit processor 1179 in the UE 1150. The data and control signals carried by the successfully decoded frames may then be provided to a data sink 1138 and the controller/processor, respectively. If some of the frames were unsuccessfully decoded by the receive processor, the controller/processor 1180 may also use an acknowledgement (ACK) and/or negative acknowledgement (NACK) protocol to support retransmission requests for those frames.

The controller/

processors

1140 and 1180 may be used to direct the operation at the NodeB 1110 and the UE 1150, respectively. For example, the controller/

processors

1140 and 1180 may provide various functions including timing, peripheral interfaces, voltage regulation, power management, and other control functions. The computer readable media of

memories

1142 and 1162 may store data and software for the NodeB 1110 and the UE 1150, respectively. A scheduler/processor 1146 at the NodeB 1110 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 herein 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, 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 herein. 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 herein 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 herein 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. ”

Claims

A method of performing gap detection for a timing acquisition in a wireless network, comprising:

performing a gap detection for identifying a gap position in a signal received in a frequency band；

determining a gap detection metric for the gap position identified by the gap detection； and

determining whether the signal is associated with a first radio access technology based at least in part on:

determining whether the gap detection metric achieves a first threshold value； and

performing one or more validating checks to further validate whether the signal is associated with the first radio access technology.
The method of claim 1, wherein determining the gap detection metric further comprises identifying the gap position in a plurality of gap position hypotheses as having a highest gap detection metric of the plurality of gap position hypotheses.
The method of claim 1, wherein performing the one or more validating checks comprises:

determining a first energy value of a first high energy zone and a second energy value of a second high energy zone of the signal for the gap position； and

determining whether the signal is associated with the first radio access technology based at least in part on whether the first energy value is greater than the second energy value multiplied by a second threshold value.
The method of claim 1, wherein performing the one or more validating checks comprises:

determining a first energy value of a first low energy zone and a second energy value of a second low energy zone of the signal for the gap position；

identifying a lowest energy value between the first energy value and the second energy value； and

determining whether the signal is associated with the first radio access technology based at least in part on whether the lowest energy value is greater than a global minimum low energy value multiplied by a third threshold value.
The method of claim 4, further comprising computing the global minimum low energy value based at least in part on determining a minimum of energy values for each of a plurality of first low energy zones and each of a plurality of second low energy zones for each of a plurality of gap position hypotheses for the signal.
The method of claim 1, wherein performing the one or more validating checks comprises:

determining first energy values of a first high energy zone and a second high energy zone at a first starting index corresponding to the gap position；

determining second energy values of the first high energy zone and the second high energy zone at a second starting index；

identifying a lowest energy value from the first energy values and the second energy values；

identifying a highest energy value between energy values of a first low energy zone and a second low energy zone at the first starting index； and

determining whether the signal is associated with the first radio access technology based at least in part on whether the lowest energy value is less than the highest energy value multiplied by a fourth threshold value.
The method of claim 1, wherein performing the one or more validating checks comprises:

computing average energy values during a plurality of consecutive chip energies；

identifying a highest energy value between energy values of a first high energy zone and a second high energy zone of the signal for the gap position； and

determining whether the signal is associated with the first radio access technology based at least in part on whether at least one of the average energy values is greater than the highest energy value multiplied by a fifth threshold value.
The method of claim 1, wherein performing the one or more validating checks comprises:

identifying a highest sample energy value contributing to an energy value of a first high energy zone or a second high energy zone of the signal for the gap position；

determining whether the signal is associated with the first radio access technology based at least in part on whether the highest sample energy value contributing to the energy value of the first high energy zone is greater than the energy value of the first high energy zone multiplied by a sixth threshold value； and

determining whether the signal is associated with the first radio access technology based at least in part on whether the highest sample energy value contributing to the energy value of the second high energy zone is greater than the energy value of the second high energy zone multiplied by the sixth threshold value.
The method of claim 1, wherein the first radio access technology is time division synchronous code division multiple access (TD-SCDMA) , and further comprising stopping the timing acquisition in TD-SCDMA where the gap detection metric does not achieve the first threshold value or where the one or more validating checks fail.
The method of claim 1, wherein performing the one or more validating checks comprises determining whether a function of one or more estimated average energy values of the signal based on the gap position achieve a second threshold value indicating that the signal is not associated with the first radio access technology.
An apparatus for performing gap detection for a timing acquisition in a wireless network, comprising:

a gap position identifying component configured to perform a gap detection for identifying a gap position in a signal received in a frequency band；

a gap detection metric determining component configured to determine a gap detection metric for the gap position identified by the gap detection；

a determining component configured to determine whether the gap detection metric achieves a first threshold value in determining whether the signal is associated with a first radio access technology； and

a validating component configured to perform one or more validating checks of the signal in determining whether the signal is associated with the first radio access technology.
The apparatus of claim 11, wherein the validating component is configured to perform the one or more validating checks at least in part by:

determining a first energy value of a first high energy zone and a second energy value of a second high energy zone of the signal for the gap position； and

determining whether the signal is associated with the first radio access technology based at least in part on whether the first energy value is greater than the second energy value multiplied by a second threshold value.
The apparatus of claim 11, wherein the validating component is configured to perform the one or more validating checks at least in part by:

determining a first energy value of a first low energy zone and a second energy value of a second low energy zone of the signal for the gap position；

identifying a lowest energy value between the first energy values and the second energy value； and

determining whether the signal is associated with the first radio access technology based at least in part on whether the lowest energy value is greater than a global minimum low energy value multiplied by a third threshold value.
The apparatus of claim 11, wherein the validating component is configured to perform the one or more validating checks at least in part by:

determining first energy values of a first high energy zone and a second high energy zone at a first starting index corresponding to the gap position；

determining second energy values of the first high energy zone and the second high energy zone at a second starting index；

identifying a lowest energy value from the first energy values and the second energy values；

identifying a highest energy value between energy values of a first low energy zone and a second low energy zone at the first starting index； and

determining whether the signal is associated with the first radio access technology based at least in part on whether the lowest energy value is less than the highest energy value multiplied by a fourth threshold value.
The apparatus of claim 11, wherein the validating component is configured to perform the one or more validating checks at least in part by:

computing average energy values during a plurality of consecutive chip energies；

identifying a highest energy value between energy values of a first high energy zone and a second high energy zone of the signal for the gap position； and

determining whether the signal is associated with the first radio access technology based at least in part on whether at least one of the average energy values is greater than the highest energy value multiplied by a fifth threshold value.
The apparatus of claim 11, wherein the validating component is configured to perform the one or more validating checks at least in part by:

identifying a highest sample energy value contributing to an energy value of a first high energy zone or a second high energy zone of the signal for the gap position；

determining whether the signal is associated with the first radio access technology based at least in part on whether the highest sample energy value contributing to the energy value of the first high energy zone is greater than the energy value of the first high energy zone multiplied by a sixth threshold value； and

determining whether the signal is associated with the first radio access technology based at least in part on whether the highest sample energy value contributing to the energy value of the second high energy zone is greater than the energy value of the second high energy zone multiplied by the sixth threshold value.
The apparatus of claim 11, wherein the first radio access technology is time division synchronous code division multiple access (TD-SCDMA) , and further comprising a gap detection manager configured to stop the timing acquisition in TD-SCDMA where the gap detection metric does not achieve the first threshold value or where the one or more validating checks fail.
The apparatus of claim 11, wherein the validating component is configured to perform the one or more validating checks at least in part by determining whether a function of one or more estimated average energy values of the signal based on the gap position achieve a second threshold value indicating that the signal is not associated with the first radio access technology.
An apparatus for performing gap detection for a timing acquisition in a wireless network, comprising:

means for performing a gap detection for identifying a gap position in a signal received in a frequency band；

means for determining a gap detection metric for the gap position identified by the gap detection；

means for determining whether the gap detection metric achieves a first threshold value in determining whether the signal is associated with a first radio access technology； and

means for performing one or more validating checks of the signal in determining whether the signal is associated with the first radio access technology.
The apparatus of claim 19, wherein the means for performing performs the one or more validating checks at least in part by:

determining a first energy value of a first high energy zone and a second energy value of a second high energy zone of the signal for the gap position； and

determining whether the signal is associated with the first radio access technology based at least in part on whether the first energy value is greater than the second energy value multiplied by a second threshold value.
The apparatus of claim 19, wherein the means for performing performs the one or more validating checks at least in part by:

determining a first energy value of a first low energy zone and a second energy value of a second low energy zone of the signal for the gap position；

identifying a lowest energy value between the first energy value and the second energy value； and

determining whether the signal is associated with the first radio access technology based at least in part on whether the lowest energy value is greater than a global minimum low energy value multiplied by a third threshold value.
The apparatus of claim 19, wherein the means for performing performs the one or more validating checks at least in part by:

determining first energy values of a first high energy zone and a second high energy zone at a first starting index corresponding to the gap position；

determining second energy values of the first high energy zone and the second high energy zone at a second starting index；

identifying a lowest energy value from the first energy values and the second energy values；

identifying a highest energy value between energy values of a first low energy zone and a second low energy zone at the first starting index； and

determining whether the signal is associated with the first radio access technology based at least in part on whether the lowest energy value is less than the highest energy value multiplied by a fourth threshold value.
The apparatus of claim 19, wherein the means for performing performs the one or more validating checks at least in part by:

computing average energy values during a plurality of consecutive chip energies；

identifying a highest energy value between energy values of a first high energy zone and a second high energy zone of the signal for the gap position； and

determining whether the signal is associated with the first radio access technology based at least in part on whether at least one of the average energy values is greater than the highest energy value multiplied by a fifth threshold value.
The apparatus of claim 19, wherein the means for performing performs the one or more validating checks at least in part by:

identifying a highest sample energy value contributing to an energy value of a first high energy zone or a second high energy zone of the signal for the gap position；

determining whether the signal is associated with the first radio access technology based at least in part on whether the highest sample energy value contributing to the energy value of the first high energy zone is greater than the energy value of the first high energy zone multiplied by a sixth threshold value； and

determining whether the signal is associated with the first radio access technology based at least in part on whether the highest sample energy value contributing to the energy value of the second high energy zone is greater than the energy value of the second high energy zone multiplied by the sixth threshold value.
A computer-readable medium storing computer-executable code for performing gap detection for a timing acquisition in a wireless network, comprising:

code for performing a gap detection for identifying a gap position in a signal received in a frequency band；

code for determining a gap detection metric for the gap position identified by the gap detection；

code for determining whether the gap detection metric achieves a first threshold value in determining whether the signal is associated with a first radio access technology； and

code for performing one or more validating checks of the signal in determining whether the signal is associated with the first radio access technology.
The computer-readable medium of claim 25, wherein the code for performing performs the one or more validating checks at least in part by:

determining a first energy value of a first high energy zone and a second energy value of a second high energy zone of the signal for the gap position； and

determining whether the signal is associated with the first radio access technology based at least in part on whether the first energy value is greater than the second energy value multiplied by a second threshold value.
The computer-readable medium of claim 25, wherein the code for performing performs the one or more validating checks at least in part by:

determining a first energy value of a first low energy zone and a second energy value of a second low energy zone of the signal for the gap position；

identifying a lowest energy value between the first energy value and the second energy value； and

determining whether the signal is associated with the first radio access technology based at least in part on whether the lowest energy value is greater than a global minimum low energy value multiplied by a third threshold value.
The computer-readable medium of claim 25, wherein the code for performing performs the one or more validating checks at least in part by:

determining first energy values of a first high energy zone and a second high energy zone at a first starting index corresponding to the gap position；

determining second energy values of the first high energy zone and the second high energy zone at a second starting index；

identifying a lowest energy value from the first energy values and the second energy values；

identifying a highest energy value between energy values of a first low energy zone and a second low energy zone at the first starting index； and

determining whether the signal is associated with the first radio access technology based at least in part on whether the lowest energy value is less than the highest energy value multiplied by a fourth threshold value.
The computer-readable medium of claim 25, wherein the code for performing performs the one or more validating checks at least in part by:

computing average energy values during a plurality of consecutive chip energies；

identifying a highest energy value between energy values of a first high energy zone and a second high energy zone of the signal for the gap position； and

determining whether the signal is associated with the first radio access technology based at least in part on whether at least one of the average energy values is greater than the highest energy value multiplied by a fifth threshold value.
The computer-readable medium of claim 25, wherein the code for performing performs the one or more validating checks at least in part by:

identifying a highest sample energy value contributing to an energy value of a first high energy zone or a second high energy zone of the signal for the gap position；

determining whether the signal is associated with the first radio access technology based at least in part on whether the highest sample energy value contributing to the energy value of the first high energy zone is greater than the energy value of the first high energy zone multiplied by a sixth threshold value； and

determining whether the signal is associated with the first radio access technology based at least in part on whether the highest sample energy value contributing to the energy value of the second high energy zone is greater than the energy value of the second high energy zone multiplied by the sixth threshold value.