KR20060089718A - Adaptive Frame Synchronization in Universal Mobile Phone System Receivers - Google Patents

Abstract

Universal Mobile Telephone System (UMTS) receiver 115 performs slot synchronization using the received Primary Synchronization Channel (PSCH) 205. Following completion of the slot synchronization, the UMTS receiver 115 adaptively controls the processing period of the secondary synchronization channel (SSCH) 210 for determining frame synchronization.

Description

ADAPTIVE FRAME SYNCHRONIZATION IN A UNIVERSAL MOBILE TELEPHONE SYSTEM RECEIVER

BACKGROUND OF THE INVENTION Field of the Invention The present invention generally relates to wireless receiving devices, and more particularly to user equipment (UE) in spread spectrum based wireless systems, such as Universal Mobile Telephone System (UMTS). equipment).

The basic unit of time for a UMTS radio signal is a 10 millisecond (ms) radio frame, which is divided into 15 slots of 2560 chips each. The UMTS radio signals sent from the cell (or base station) to the UMTS receiver are referred to as "downlink signals" and the radio signals in the reverse direction are referred to as "uplink signals". When the UMTS receiver is first turned on, the UMTS receiver does a "cell search" to search for the cell with which it is communicating. Specifically, as described below, the UMTS receiver first looks for a downlink synchronization channel (SCH) transmitted from a cell to synchronize at that slot and frame level, and then a specific scrambling code of that cell. Determine the group. Only after the cell search is successful, voice / data communication is started.

For cell search, the SCH is a sparse downlink channel that is active only for the first 256 chips of each slot. The SCH is composed of two subchannels, a primary SCH (PSCH) and a secondary SCH (SSCH). The PSCH 256 chip sequence, or PSCH code, is the same in every slot of the SCH for every cell. Conversely, the SSCH 256 chip sequence, or SSCH code, may be different in each of 15 slots of a radio frame and is used to identify one of 64 possible scrambling code groups. In other words, each radio frame of the SCH repeats a scrambling code group sequence associated with each transmission cell. Each SSCH code is taken from the alphabet of 16 possible SSCH codes.

As part of cell search, the UMTS receiver first uses the PSCH to achieve slot synchronization. In this regard, the UMTS receiver correlates received samples of the received PSCH to a known PSCH 256 chip sequence (same for all slots) and based on the location of the correlation peak, the slot reference time. Decide Once the slot reference time is determined, the UMTS receiver is slot synchronized and can determine when each slot starts in the received radio frame.

After slot synchronization, the UMTS receiver stops processing of the PSCH and starts processing of the SSCH. Specifically, the UMTS receiver correlates a particular sequence of the 15 SSCH codes of the received radio frame with a known sequence to achieve frame synchronization and determine a group of scrambling codes of the cell. The identification of the scrambling code group then enables the UMTS receiver to descramble all other downlink channels of the cell in order to initiate voice / data communication.

Unfortunately, the above-described SSCH portion of the cell search process is the most time consuming portion. Specifically, because of the low signal-to-noise ratio at which the UMTS system can operate, the UMTS receiver can select a predetermined number of received radio frames, eg, to obtain a good estimate of the transmitted sequence of 15 SSCH codes from the cell. For example, 10 to 20 radio frames are processed. As such, since each radio frame has a length of 10 ms, the user will experience a delay of at least 100 to 200 ms before the voice / data communication begins.

As discussed above, the UMTS receiver performs the SSCH portion of cell search by processing a predetermined number of received radio frames. However, it has been found that a UMTS receiver-allowed by channel conditions-can successfully determine the scrambling code group even after achieving frame synchronization and processing one received radio frame. In other words, in some channel conditions, the UMTS receiver wastes time by processing unnecessary received radio frames. Accordingly, and in accordance with the principles of the present invention, a UMTS receiver receives an SCH channel comprising an SSCH subchannel and adaptively controls the duration of the SSCH-related processing to determine frame synchronization.

In one embodiment of the invention, the UMTS receiver is part of a UMTS user equipment (UE). The UMTS receiver first performs slot synchronization using the PSCH and determines a peak correlation value associated with the received PSCH codes. After achieving slot synchronization, the UMTS receiver determines the number of received radio frames required to determine frame synchronization as a function of the determined peak correlation value and possibly other correlation values. The UMTS receiver performs frame synchronization based on the determined number of received radio frames.

According to another embodiment of the present invention, the UMTS receiver is part of a UMTS user equipment (UE). The UMTS receiver first performs slot synchronization using a PSCH. After achieving slot synchronization, the UMTS receiver initiates frame synchronization processing using the SSCH. During the frame synchronization process, the UMTS receiver checks whether a group of scrambling codes can be determined after every received radio frame. Once the scrambling code group is determined, the UMTS receiver stops further SSCH processing of the received radio frames and completes frame synchronization according to the determination of the scrambling code.

1 is a diagram illustrating a portion of an exemplary wireless communication system in accordance with the principles of the present invention.

2 and 3 are diagrams illustrating exemplary embodiments of a wireless receiver in accordance with the principles of the present invention.

4 illustrates an exemplary flow chart in accordance with the principles of the present invention.

5 illustrates an exemplary frame table in accordance with the principles of the present invention.

6 is a diagram illustrating an exemplary pseudo code implementation in accordance with the principles of the present invention.

7 and 8 illustrate alternative implementations in accordance with the principles of the invention.

9 and 10 illustrate other exemplary flowcharts in accordance with the principles of the present invention.

Other than the concept of the invention, the elements shown in the figures are well known and will not be described in detail. In addition, since closeness with a UMTS-based wireless communication system is assumed, this will not be described in detail herein. For example, spread spectrum transmission and reception, cells (base stations), user equipment (UE), downlink channels, uplink channels, and RAKE receivers, other than the inventive concept, are well known, Will not be explained in. In addition, the inventive concept may be implemented using conventional programming techniques, which will likewise not be described herein. Finally, like-numbers described in the figures indicate similar elements.

An exemplary portion of a UMTS wireless communication system 10 in accordance with the principles of the present invention is shown in FIG. The cell (or base station) 15 broadcasts a downlink synchronization channel (SCH) signal 16 comprising the aforementioned PSCH and SSCH subchannels. As mentioned above, the SCH signal 16 is used by the UMTS user equipment (UE) for synchronization purposes as a pre-condition for voice / data communication. For example, the UE processes the SCH signal during a "cell search" operation. In this example, the UE 20, eg, a cell phone, initiates cell search, for example when the UE 20 is turned on or powered up. The purpose of the cell search operation includes (a) synchronization for cell transmission at the slot and frame level of the UMTS radio frame, and (b) determination of the scrambling code group of the cell (eg, cell 15). do. As described below, and in accordance with the principles of the present invention, the UE 20 adaptively controls the duration of the processing of the SSCH portion of the SCH to determine frame synchronization. The following examples will illustrate the concept of the present invention in the context of this initial cell search, i.e., when the UE 20 is turned on, but the concept of the present invention is not limited thereto, and other examples of cell search, For example, it should be understood that it can be applied even when the UE is in "idle mode".

Referring now to FIG. 2, an exemplary block diagram of a portion of a UE 20 in accordance with the principles of the present invention is shown. The UE 20 includes a front end 105, an analog-to-digital (A / D) converter 110, a cell search element 115, a searcher element 120, and a rake receiver ( 125, host interface block 130, and processor 135. Additional elements other than the inventive concept may be included in the blocks shown in FIG. 2 as known in the prior art, but are not described herein for the sake of clarity. For example, the A / D converter 110 may include a digital filter, a buffer, and the like.

The front end 105 receives a radio-frequency (RF) signal 101 transmitted from the cell 15 (FIG. 1) via an antenna (not shown) and a baseband analog signal representing the PSCH and SSCH subchannels. 106 is supplied. The baseband analog signal 106 is sampled by the A / D converter 110, which supplies a stream 111 of received samples. The received samples 111 are available for three components: cell search element 115, searcher element 120, and rake receiver 125. The cell search element 115 processes the PSCH and SSCH subchannels, in accordance with the principles of the present invention as further described below. Following a successful cell search, the searcher element 120 evaluates the received samples for multipath allocation to each of the fingers of the rake receiver 125, which rake receiver 125, For example, data may be combined from multipaths in providing symbols for subsequent decoding by a decoder (not shown) to provide voice / data communication. Since only cell search element 115 relates to the inventive concept, search component 120 and rake receiver 125 are not further described herein. The host interface block 130 connects the data between the three components described above and the processor 135, whereby the processor 135 receives the result from the cell search element 115 via signaling 134. . Processor 135 is illustratively a program-stored control processor, eg, a microprocessor, and includes memory 140 for storing programs and data.

Referring now to FIG. 3, an exemplary block diagram of the cell search element 115 is shown. The cell search element 115 includes a PSCH element 205 and an SSCH element 210. Referring also to FIG. 4, FIG. 4 shows an exemplary flowchart in accordance with the principles of the present invention for processing downlink PSCH and SSCH subchannels with the cell search element 115 of FIG. Processor 135 of UE 20 initiates cell search in step 305 to achieve slot synchronization by processing the downlink PSCH subchannel in step 305. Specifically, processor 135 activates PSCH element 205 via signaling 206 to process received samples 111 as known in the art. For example, the downlink PSCH subchannel is a known PSCH 256 chip sequence, or a PSCH code that occurs periodically (ie, repeats in every slot of the downlink SCH signal), and the PSCH element 205 is a PSCH code for the PSCH code. Correlate the received samples 111 and provide a combined peak correlation value. Here, the PSCH element 205 includes a matched filter and a buffer (both not shown) that stores the output signal of the matched filter. The PSCH element 205 supplies the peak correlation value to the processor 135 via signaling 206. This peak correlation value may be averaged over multiple slots, eg, 4-20 slots, of the received radio frame (s), to reduce the likelihood of "false lock." (This is much faster than conventional SSCH frame synchronization, as PSCH synchronization uses multiple-not frame-slots.) If the peak correlation value is not greater than the predetermined threshold, then the processor 135 is configured to use the PSCH element ( 205 will continue to process any received signals to continue searching for the cell. However, if the peak correlation value is greater than the predetermined threshold, the UE 20 completes the slot synchronization. In an alternative method, slot synchronization is considered complete if the peak correlation value exceeds the next highest correlation value by a predetermined addition or multiple factor.

Next, at step 310, in accordance with the principles of the present invention, the processor 135 adaptively determines the duration of subsequent SSCH processing as a function of the peak correlation value obtained from slot acquisition. Specifically, the processor 135 determines the number of received radio frames and proceeds to frame synchronization as a function of the peak correlation value determined in the execution of step 305. In other words, the number of frame repetitions for the SSCH process is based, for example, on the strength of the PSCH correlation peak, which is used as an indication of the condition of the communication channel. Although any function may be used, illustratively, the number of frame repetitions required for SSCH processing may be considered as inversely proportional to the magnitude of the primary SCH correlation peak. For example, if the value of the PSCH correlation peak is very large above the predetermined level, the SSCH process uses only one frame of data, but if the value of the PSCH correlation peak is slightly smaller, two frames or the like will be processed. . Here, the processor 135 uses the example frame number table, or, which is the number of frames required for the SSCH treatment and is equal to N and the first (priori) coupled PSCH correlation peak value. This exemplary table 41 is shown in FIG. 5. The table 41 is illustratively stored in the memory 140 of the UE 20. Each row of the table 41 combines the PSCH correlation peak value, k _i , the number of frames required for SSCH processing, N , where k _{i &} gt; k _{i + 1} . For example, in step 310, if the correlation peak value is k ₁ or more, the processor 135 controls SSCH processing to use only one received frame ( N = 1 ). It is to be understood that the actual correlation peak values and the combined number of frames, N, are empirically determined, which is not described herein. As such, the table 41 may include any number of rows depending on the efficiency found empirically in the SSCH processing. It is to be understood that other variations are possible, for example, the number of frames, N , may be determined as a function of a plurality of correlation values, which may or may not include a peak correlation value.

Referring back to FIG. 4, once the number of received frames to process is determined, the processor 135 may process the received samples 111 for the determined number of frames, N , by the SSCH element 210 at step 315. To help. The SSCH element 210 is connected to the processor 135 via signaling 211, achieves frame synchronization, and determines the scrambling code group of the cell (here, the scrambling code group coupled to the cell 15). For a known sequence for use, correlate a particular sequence of SSCH codes in a received radio frame. In accordance with the principles of the present invention, SSCH processing is performed on the determined number of received radio frames, N , to average correlation values over successive frames of data to obtain a robust estimate of the received 15 SSCH code sequence. In particular, if N = 1 , there are no consecutive frames. For clarity, error conditions are not shown in the flowcharts disclosed herein. For example, if the UE 20 loses slot synchronization while attempting frame synchronization, the cell search described above is unfortunately restarted.

In addition to the inventive concept, step 315 corresponds to SSCH processing as is known in the art and is exemplarily performed by SSCH element 210 and processor 135 in FIGS. 2 and 3, respectively. As a background technique, the UE 20 must determine which of the 64 scrambling code groups will be used by the cell 15, where each scrambling code group is identified by a particular sequence of 15 SSCH codes. As used herein, 64 scrambling code groups form a set of scrambling code groups. In the formation of a scrambling code group, each SSCH code, or symbol, is taken from, for example, an alphabet of 16 symbols of 1-16. As such, an exemplary scrambling code group, for example, group 1, may include the following 15 SSCH symbols.

[1 1 2 8 9 10 15 8 10 16 2 7 15 7 16]

Another scrambling code group, for example, group 2, may include the following 15 SSCH symbols.

[1 1 5 16 7 3 14 16 3 10 5 12 14 12 10]

However, since frame synchronization has not yet been achieved, the received specific sequence of 15 SSCH codes may be shifted from each scrambling code group to a predetermined position. Accordingly, in UMTS, scrambling code groups are prioritized so that the periodic-shifts of these groups become specific, i.e., the periodic shift of any scrambling code group is not the same as any other scrambling code group. Thus, because frame synchronization has not yet been achieved, the received sequence of 15 SSCH codes is compared with all 15 possible periodic shifts of all 64 possible scrambling code groups to identify the received scrambling code group and periodically The frame offset is determined to achieve frame synchronization from the shift. (Periodic shifts include zero shifts, that is, it should be understood that there are no actual shifts in the scrambling code group sequence.) This is compared to a possible sequence of (64) (15) = 960 , which is generally 64 It is performed in software in the form of an aggregated loop for possible scrambling code groups and 15 possible shifts within each scrambling code group. An example pseudo code implementation for identifying a received scrambling code group and determining a frame offset by comparing the received sequence of 15 SSCH codes against all 15 possible periodic shifts of all 64 possible scrambling code groups. This is shown in FIG. 6, the comparison between the parameter peak_idx_buff (received samples) and the parameter code_groups (stored lookup table of 15 values of all 64 possible code groups) is made (64) (15) (15) = 14400 times. Must be

If the SSCH processing is successfully completed in step 315, the UE 20 may use the common pilot channel (CPICH) (eg, frequency synchronization and also used to determine the actual scrambling code for the cell from the identified scrambling code group). The scrambling code group of cell 15, which enables to descramble all other downlink channels of the cell (including the Common Pilot Channel), can be identified and voice / data communication can begin.

As is apparent from the above description, the throughput for comparing the received sequence of 15 SSCH codes with all 15 possible periodic shifts of all 64 possible scrambling code groups is quite large. However, in accordance with the principles of the present invention, this throughput is reduced for exiting the collected loop when a predetermined number of matches, or mismatches, are satisfied for a given scrambling code group and sequence. Can be. An exemplary flow chart of this alternative implementation is shown in FIG. 7. In connection with this implementation, the following data is tracked by the processor 135:

Target_sequence— specific periodic shift of a particular scrambling code group, ie one of 960 possible sequences;

Experimental_best_match- scrambling code group sequence that is the current best match for the received sequence, initially set to null;

Best_mismatch -the number of mismatches between the experimental best match and the received sequence, initially set to a value of 15;

Best match _-trial maximum number of matches between the received sequence and the match, setting the first value 0;

Mismatch -current number of mismatches between received sequence and target_sequence, initially set to a value of 0 at the beginning of each comparison;

Match -The current number of matches between the received sequence and the target_sequence, initially set to a value of zero at the beginning of each comparison.

In step 605, a sequence of fifteen SSCH codes is received for processing. Step 610 represents a comparison loop (hereafter loop 610) comprising steps 611 and 612. In step 611, the symbols of the received sequence are compared with the corresponding symbols of the target_sequence (one of the 960 possible sequences described above). As each symbol position is processed, each variable mismatch and match is updated accordingly. For example, if a particular comparison between the received symbol and each symbol in the target_sequence does not match, the value of the mismatch is increased. Similarly, if this comparison matches, the value of the match increases. In step 612, the current value of the mismatch is compared with the value of the highest_mismatch after every symbol comparison. If the value of the mismatch is greater than or equal to the value of the highest_mismatch, processor 135 breaks out in loop 610, so that the new sequence of received sequences for the next possible sequence, i.e., the new target_sequence , is new. Start the comparison. When a new comparison begins, the variable match and mismatch are reset to the value zero. In other words, if the number of mismatches is the same as the mismatches for the current best match, then the current search or comparison is aborted. This saves processing time. Specifically, if a given received sequence has the same number of mismatches as the previous best match sequence, the current comparison will ensure the best match, i.e. the further comparison will not provide any further information.

On the other hand, if loop 610 completes the comparison between the received sequence and the target_sequence without breaking out of the loop, a better match is found. In this case, the variable experimental_best_match is updated with the target_sequence information (as both the scrambling code group and the periodic shift), the variable best_mismatch is updated with the values of the mismatches, and the value of the best_match. Is updated with the values of the matches. In step 615, the value of the highest_match is compared with a predetermined threshold. If the value of Best_Match is less than the predetermined threshold, the comparison for possible sequences will continue in loop 610 as described above. However, if the value of the highest_match is above the predetermined threshold, then the experimental_best_match is considered to be a group of received scrambling codes, and the combined periodic shift is used to determine the frame offset. The predetermined threshold may be set to, for example, 15 representing a complete match, or the predetermined threshold may be set to a lower value, eg, 10 matches. Matches of less than 15 matches are desirable to use under poor signal-to-noise ratio environments because full matches cannot be obtained. This user-specified threshold of less than 15 should be chosen high enough to ensure a certain likelihood of success and to ensure that the wrong sequence is not selected by accident. An example pseudo code implementation of the method of FIG. 7 is shown in FIG. 8.

As described above, the processor 135 adaptively determines the duration of subsequent SSCH processing as a function of the peak correlation value obtained from slot acquisition. In the above embodiment, the processor 135 determines the number of frames, N, to process. However, other alternatives in accordance with the principles of the present invention are possible. Referring now to FIG. 9, another exemplary embodiment is shown. In this exemplary embodiment, the accumulated data representing the sequence of 15 SSCH codes is checked after every frame repetition. If there are enough matches to identify a particular 15 SSCH code sequence, the SSCH processing is stopped by the processor 135. As such, SSCH processing may be aborted even after one received radio frame has been processed. Specifically, after obtaining slot synchronization (as indicated by step 305 of FIG. 4) described above, processor 135 enables SSCH processing. In step 405 of FIG. 9, the SSCH element 210 processes the received radio frames one frame at a time as described above. As a result of this processing, once each successive frame is processed, the SSCH element 210 accumulates a correlation value for the received sequence of 15 SSCH codes over time in step 410. SSCH element 210 continues to process each received frame and accumulate data over time in steps 405 and 410 until interrupted by processor 135 (described below). In step 415, the processor 135 determines the number of matches between the SSCH codes (possible scrambling code group) represented by the accumulated correlation value and each one of the 64 scrambling code groups of the scrambling code group set. do. For example, if the correlation value accumulated from step 410 is a representation of the following received SSCH sequence (possible scrambling code group):

[1 1 2 8 9 5 5 5 5 5 5 5 5 5 5],

There are five matches combined with scrambling code group 1 and only two matches combined with scrambling code group 2 (group 1 and group 2 are exemplarily defined in advance).

In accordance with the flowchart of FIG. 9, at step 420, the processor 135 determines whether the number of matches exceeds a predetermined threshold, eg, at least 13 SSCH codes of the scrambling code group of the scrambling code group set are the highest 15. Determine if it matches a possible match. If none of the scrambling code groups of the scrambling code group set have a number of combined matches that exceed a predetermined threshold, the processor 135 continues processing at step 415 so that the next received frame is a SSCH element ( The accumulated correlation value as being updated after being processed by 210 is checked. However, if the number of matches for one of the scrambling code groups of the scrambling code group set exceeds a predetermined threshold, the SSCH processing is stopped at step 425, and this scrambling code group from the scrambling code group set is scrambling at step 430. It is selected as a code group. As such, once the SSCH processing is completed at step 430 and the scrambling code group of the cell 15 is identified, the UE 20 may (eg, synchronize frequency synchronization and the actual scrambling code group from the identified scrambling code group). All other downlink channels of the cell (including the common pilot channel (CPICH), used to determine the scrambling code) can be descrambled and voice / data communication can begin.

As is apparent from FIG. 9, it may be the case that multiple scrambling code groups have the same number of matches. For example, scrambling code group 5 is

[1 2 3 4 5 6 7 8 9 10 11 12 13 14 15],

Scrambling code group 7,

[15 14 13 12 11 10 9 8 7 6 5 4 3 2 1]

Assume that the accumulated correlation value from step 410 represents the following received SSCH sequence (possible scrambling code group):

[1 2 3 4 5 5 5 5 5 5 5 4 3 2 1].

If in step 420 the threshold of the predetermined number of matches is set to 5 illustratively, there are five matches for both scrambling code group 5 and scrambling code group 7 of the scrambling code group set. In this case, the selection of a particular scrambling code group is not trusted. The flowchart shown in FIG. 10 adds an additional step 435, in which, if the predetermined threshold is exceeded, the scrambling code group is selected from the set of scrambling code groups having the most matches. If there is no scrambling code group with the most matches, processing proceeds to step 415 as described above. However, if one scrambling code group has the most matches, the SSCH processing is stopped at step 425 and this scrambling code group of the scrambling code group set is selected as the scrambling code group at step 430.

As noted above, in accordance with the principles of the present invention, the wireless receiver adaptively determines the SSCH processing period, thereby reducing the number of received frames that are processed, and ideally, therefore, the least number of received frames will achieve frame synchronization. Is processed to achieve. Although described in the context of initial cell search processing, the concept of the present invention is that a downlink channel, such as an SSCH subchannel, can be applied to any portion of radio operation where the channel environment is changed.

The foregoing is merely illustrative of the principles of the invention and, therefore, those skilled in the art, although not explicitly described herein, employ many of the alternative configurations that incorporate the principles of the invention and are included within the spirit and scope of the invention. You can devise it. For example, although illustrated as separate functional elements in this context, these functional elements may be one or more integrated circuits (ICs) and / or one or more stored program-controlled processors (eg, a microprocessor or digital signal processor). (DSP)). Similarly, while illustrated in the context of a UMTS-based system, the concepts of the present invention can be applied to any communication system that processes signals when the channel environment changes. Accordingly, it should be understood that many modifications may be made to the exemplary embodiments, and that other configurations may be devised without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (20)

In a method for use in a wireless receiver, Processing 305 a first synchronization channel of the received wireless signal to achieve slot synchronization, and Adaptively controlling 310 a period of processing a second synchronization channel of the received wireless signal to achieve frame synchronization How to include. The system of claim 1, wherein the first synchronization channel is a primary synchronization subchannel (PSCH) of a universal mobile telephone system (UMTS), and the second synchronization channel is a universal mobile telephone system (U.S.). A secondary synchronization subchannel (SSCH) of the UMTS. 2. The method of claim 1, wherein processing the first synchronization channel comprises providing a peak correlation value associated with the first synchronization channel. The method of claim 3, wherein adaptively controlling the period of processing the second synchronization channel comprises: Determining the number of received frames of the received wireless signal as a function of the peak correlation value, and Processing the second synchronization channel for the determined number of frames to achieve frame synchronization How to include. The method of claim 4, wherein processing the second synchronization channel comprises: Comparing the estimated received sequence with each one of the plurality of possible received sequences, each sequence comprising a plurality of symbols, and After each comparison to one of the plurality of possible sequences, identifying one of the plurality of possible sequences as the best possible match. Including, In the comparing step, if the number of mismatches for the current comparison is greater than or equal to the number of mismatches combined with the highest possible match, then the current comparison is stopped and a new comparison is started. 2. The method of claim 1, wherein processing the first synchronization channel comprises providing a plurality of correlation values, including a peak correlation value, associated with the first synchronization channel. The method of claim 6, wherein adaptively controlling the period of processing the second synchronization channel comprises: Determining the number of received frames of the received wireless signal as a function of the peak correlation value and at least one other value, and Processing the second synchronization channel for the determined number of frames to achieve frame synchronization How to include. 8. The method of claim 7, wherein processing the second synchronization channel comprises: Correlating the received wireless signal to provide an estimate of the received sequence for the determined number of frames, Comparing each one of a plurality of predicted received sequences with the estimated received sequence to determine the number of matches; and If the number of matches for at least one of the plurality of predicted received sequences exceeds a predetermined threshold, breaking out processing the second synchronization channel. How to include. The method of claim 1, wherein adaptively controlling the period of processing the second synchronization channel comprises: Processing the second synchronization channel to form accumulation data representing a possible group of scrambling codes comprising an M symbol sequence, Determining the number of matches between the M symbol sequence of the possible scrambling code group and each scrambling code group of the set of scrambling code groups, and Selecting the at least one scrambling code group as a scrambling code group for use in achieving frame synchronization if the determined number of matches for at least one scrambling code group of the set of scrambling code groups exceeds a predetermined value. step How to include. 10. The method of claim 9, wherein the step of selecting includes stopping further processing of received frames of the received wireless signal. The method of claim 9, wherein the selecting step, If the one or more scrambling code groups of the scrambling code group set exceed the determined number of matches, selecting a scrambling code group having the most number of matches. How to include. In a method for use in a wireless receiver, Processing (305) a first synchronization channel of the wireless signal, received from the wireless communication channel to achieve slot synchronization, to provide a signal indicative of a condition of the wireless communication channel, Determining the number of received frames using the value of the signal for indexing into a table, and Processing a second synchronization channel of the wireless signal for at least the determined number of received frames to achieve frame synchronization How to include. The method of claim 12, wherein processing the second synchronization channel comprises: Comparing the estimated received sequence with each one of the plurality of possible received sequences, each sequence comprising a plurality of symbols, and After each comparison to one of the plurality of possible sequences, identifying one of the plurality of possible sequences as the best possible match. Including, In the comparing step, if the number of mismatches for the current comparison is greater than or equal to the number of mismatches combined with the highest possible match, the current comparison is stopped and a new comparison is started. In Universal Mobile Phone System (UMTS) equipment, A front end 105 that receives a wireless signal indicative of a sequence of frames and provides a stream of samples received therefrom, and A processor 135 for adaptively controlling a time period for performing frame synchronization on the received samples UMTS equipment comprising a. The method of claim 14, A primary synchronization element 205 operating on received samples to achieve slot synchronization with the primary synchronization signal of the received wireless signal and to provide a peak correlation value combined with the primary synchronization element, and A secondary synchronization element 210 operating on received samples to achieve frame synchronization for the secondary synchronization signal of the received wireless signal. More, And the processor determines a number of frames for the secondary synchronization element to process as a function of the peak correlation value to achieve frame synchronization. 16. The UMTS apparatus of claim 15, wherein the processor determines the number of frames for the secondary synchronization element to process to achieve frame synchronization as a function of the peak correlation value and at least one other correlation value. The method of claim 14, A primary synchronization element 205 operating on received samples, to achieve slot synchronization for the primary synchronization signal of the received wireless signal, and Secondary synchronization element 210 operating on received samples following slot synchronization to provide a possible group of scrambling codes comprising an M symbol sequence. More, The processor determines (a) the number of matches between the M symbol sequence of the possible scrambling code group and each scrambling code group of the set of scrambling code groups, and (b) at least one scrambling of the set of scrambling code groups The scrambling code group for use in achieving frame synchronization if the determined number of matches for a code group exceeds a predetermined value, selecting the at least one scrambling code group. 18. The UMTS equipment of claim 17, wherein the processor stops further processing of received frames of the received wireless signal if the determined number of the matches for the at least one scrambling code group exceeds the predetermined value. 18. The UMTS equipment of claim 17, wherein if the one or more scrambling code groups of a set of scrambling code groups exceeds the determined number of matches, the processor selects a scrambling code group having the maximum number of matches. In Universal Mobile Phone System (UMTS) equipment, A front end 105 for receiving a radio signal indicative of a sequence of frames, wherein each frame carries a primary synchronization signal and a secondary synchronization signal; A memory 140 for storing a table for combining the number of received frames with a correlation value, the correlation value being combined with the received primary synchronization signal, and A processor 135 that limits the processing of the secondary synchronization signal to the combined number of received frames UMTS equipment comprising a.

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