HK1182874A - Power efficient paging channel decoding - Google Patents

Abstract

The present disclosure is directed to a device, method and system for power efficient paging channel decoding. Disclosed are various embodiments of extracting a paging message from paging channel downlink communications. A first and second page bursts and received. When the signal to noise ratio of the first and second bursts exceeds a threshold, a Viterbi decoder is executed and an error checking code calculated to determine whether the paging message is successfully extracted. If not, a third page burst is received and a Viterbi decoder executed to extract the paging message.

Description

Power efficient paging channel decoding

Cross Reference to Related Applications

Priority of co-pending U.S. provisional application serial No. 61/565,864 entitled "cellular baseband processing", filed 12/1/2011, which is incorporated herein by reference in its entirety. This application also claims priority to co-pending U.S. provisional application serial No. 61/568,868 entitled "cellular baseband processing," filed 12, 9, 2011, which is incorporated herein by reference in its entirety. This application also claims priority to U.S. application serial No. 13/404,147 entitled "power efficient paging channel decoding" filed on 24/2/2012, which is incorporated herein by reference in its entirety.

Technical Field

The present disclosure relates to power efficient paging channel decoding.

Background

Cellular wireless communication systems support wireless communication services in many populated areas of the world. Although originally established to serve voice communications, cellular wireless communication systems are now also required to support data communications. The demand for data communication services has grown explosively with the acceptance and widespread use of the internet. While data communications have historically been serviced via wired connections, cellular wireless users now demand that their wireless units also support data communications. Many wireless users now desire to be able to "surf" the internet, access their email, and perform other data communication activities using their cellular phones, wireless personal data assistants, wirelessly linked notebook computers, and/or other wireless devices. The need for data communication in wireless communication systems will only increase day by day. As a result, cellular wireless communication systems are now being established/modified to service these rapidly increasing communication demands.

Cellular wireless networks include a "network infrastructure" that wirelessly communicates with wireless terminals and/or mobile devices within respective service coverage areas. The network infrastructure typically includes a plurality of base stations dispersed throughout a service coverage area, each of which supports wireless communications within a respective cell (or group of areas). The base stations are coupled to Base Station Controllers (BSCs), where each BSC serves a plurality of base stations. Each BSC is coupled to a Mobile Switching Center (MSC). Each BSC is also typically coupled, directly or indirectly, to the internet.

In operation, each base station communicates with a plurality of wireless terminals operating within its cell/area. A BSC coupled to the base station routes voice communications between the MSC and the serving base station. The MSC routes the voice signal to other MSCs or to the PSTN. Typically, the BSC routes data communications between the serving base station and a packet data network, which may include and/or be coupled to the internet. Transmissions from a base station to a wireless terminal are referred to as "forward link" transmissions, while transmissions from a wireless terminal to a base station are referred to as "reverse link" transmissions. The amount of data transmitted on the forward link typically exceeds the amount of data transmitted on the reverse link. This is the case because the data consumer typically issues instructions to request data from a data source, such as a web server, which provides the data to the wireless terminal.

The radio link between a base station and its served wireless terminals typically operates in accordance with one (or more) of a number of operating standards. These operating standards define the manner in which radio links can be assigned, established, serviced, and torn down. One popular cellular standard is the global system for mobile communications (GSM) standard. The GSM standard, or simply GSM, is dominant in europe and is used globally. While GSM originally served only voice communications, it has now been modified to also serve data communications. In GSM, a wireless terminal learns of incoming communications that need to be serviced via a page from a base station to the wireless terminal. Enhanced data rates for GSM General Packet Radio Service (GPRS) operations and GSM (or global) evolution (EDGE) operations coexist with GSM by sharing the channel bandwidth, slot structure, and slot timing of the GSM standard. GPRS operation and EDGE operation may also serve as migration paths for other standards, such as IS-136 and Public Digital Cellular (PDC).

To conserve power, a wireless terminal may sleep when not actively communicating with a serving base station. However, to ensure that no communication is missed, the wireless terminal periodically wakes up to receive a paging pulse indicating whether the wireless terminal must service a communication from a serving base station, processing operations are often scheduled to track the receipt of a page. Since operations are scheduled prior to the actual knowledge of the information included in the page, these processing operations are often separated for tracking of multiple pages. To achieve this decision, the wireless terminal typically consumes a significant amount of battery power and processing resources to decode the paging pulse to determine whether the wireless terminal is paged and to perform scheduled processing operations. Therefore, there is a need for a wireless terminal that can efficiently decode paging pulses in order to limit power consumption.

Disclosure of Invention

(1) A wireless communications apparatus, comprising: at least one Radio Frequency (RF) transceiver configured to receive a first encoded paging pulse and a second encoded paging pulse; a baseband processor configured to: identifying a first signal-to-noise ratio of the first encoded paging pulse; identifying a second signal-to-noise ratio of the second encoded paging pulse; extracting a first encoded signal from the first encoded paging pulse and the second encoded paging pulse when the first signal-to-noise ratio and the second signal-to-noise ratio exceed predetermined thresholds; calculating an error check value associated with the encoded signal; determining whether the error-checking value matches an embedded error-checking value decoded from the first encoded signal; and initiating processing of a third encoded paging pulse when the error-checking value does not match the embedded error-checking value.

(2) The system of (1), wherein the baseband processor is configured to extract the first encoded signal from the first encoded paging pulse and the second encoded paging pulse by executing a viterbi decoder.

(3) The system of (1), wherein the baseband processor is further configured to: initiating processing of a third encoded paging pulse when the error-checking value does not match the embedded error-checking value; and extracting a second encoded signal from the first encoded paging pulse, the second encoded paging pulse, and the third encoded paging pulse.

(4) The system of (1), wherein the baseband processor is further configured to: initiating processing of a third encoded paging pulse when at least one of the first signal-to-noise ratio and the second signal-to-noise ratio does not exceed the threshold; and extracting a second encoded signal from the first encoded paging pulse, the second encoded paging pulse, and the third encoded paging pulse.

(5) The system of (4), wherein the baseband processor is configured to extract the second encoded signal from the first encoded paging pulse, the second encoded paging pulse, and the third encoded paging pulse by executing a viterbi decoder.

(6) The system of (1), wherein the encoded signal is encoded with a 1/2 rate convolutional code.

(7) The System of (1), wherein the first paging pulse and the second paging pulse are received in a Mobile packet System (GSM) paging channel.

(8) The system of (1), wherein the threshold is based at least in part on a probability that the error check value matches an embedded error check value decoded from the first encoded signal.

(9) The system of (1), wherein the embedded error-checking value decoded from the first encoded signal further comprises a cyclic redundancy check code based on the first encoded signal.

(10) A method performed in a wireless terminal for extracting a coded signal from a wireless signal, comprising the steps of: receiving a first encoded paging pulse and a second encoded paging pulse; identifying a first signal-to-noise ratio of the first encoded paging pulse; identifying a second signal-to-noise ratio of the second encoded paging pulse; extracting a first encoded signal from the first encoded paging pulse and the second encoded paging pulse when the first signal-to-noise ratio and the second signal-to-noise ratio exceed predetermined thresholds; calculating an error check value associated with the encoded signal; determining whether the error-checking value matches an embedded error-checking value decoded from the first encoded signal; and initiating processing of a third encoded paging pulse when the error-checking value does not match the embedded error-checking value.

(11) The method of (10), wherein extracting the first encoded signal from the first encoded paging pulse and the second encoded paging pulse further comprises: performing a Viterbi decoder on a designated time slot of the first encoded paging pulse and a corresponding designated time slot of the second encoded paging pulse.

(12) The method according to (10), further comprising the steps of: initiating processing of a third encoded paging pulse when the error-checking value does not match the embedded error-checking value; and extracting a second encoded signal from the first encoded paging pulse, the second encoded paging pulse, and the third encoded paging pulse.

(13) The method according to (10), further comprising the steps of: initiating processing of a third encoded paging pulse when at least one of the first signal-to-noise ratio and the second signal-to-noise ratio does not exceed the threshold; and extracting a second encoded signal from the designated time slots of the first encoded paging burst, the second encoded paging burst, and the third encoded paging burst.

(14) The method of (13), further comprising: extracting the second encoded signal from the first encoded paging pulse, the second encoded paging pulse, and the third encoded paging pulse by performing a step of a viterbi decoder.

(15) The method of (10), wherein the encoded signal is encoded using a 1/2 rate convolutional code.

(16) The method of (10), wherein the first paging pulse and the second paging pulse are received in a Mobile packet System (GSM) paging channel.

(17) The method of (10), wherein the threshold is based at least in part on a probability that the error check value matches an embedded error check value decoded from the first encoded signal.

(18) The method of (10), wherein the embedded error-checking value decoded from the first encoded signal further comprises a cyclic redundancy check code based on the first encoded signal.

(19) A system, comprising: means for receiving a first encoded paging pulse and a second encoded paging pulse; means for identifying a first signal-to-noise ratio of the first encoded paging pulse; means for identifying a second signal-to-noise ratio of the second encoded paging pulse; means for extracting a first encoded signal from the first encoded paging pulse and the second encoded paging pulse when the first signal-to-noise ratio and the second signal-to-noise ratio exceed a predetermined threshold; means for calculating an error check value associated with the encoded signal; means for determining whether the error-checking value matches an embedded error-checking value decoded from the first encoded signal; and means for initiating processing of a third encoded paging pulse when the error-checking value does not match the embedded error-checking value.

(20) The system of (19), further comprising: means for initiating processing of a third encoded paging pulse when the error-checking value does not match the embedded error-checking value; and means for extracting a second encoded signal from the first encoded paging pulse, the second encoded paging pulse, and the third encoded paging pulse.

Drawings

Various aspects of the invention may be better understood with reference to the following drawings. The components in the figures are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present invention. Moreover, in the figures, like reference numerals designate corresponding parts throughout the several views.

Fig. 1 is a system diagram illustrating a portion of a wireless communication system supporting mobile devices and/or wireless terminals operating in accordance with the present invention.

Fig. 2 is a block diagram functionally illustrating a mobile device according to an embodiment of the present disclosure.

Fig. 3 is a block diagram illustrating a form of paging channel downlink transmission.

Fig. 4 is a flow chart illustrating operation of a mobile device that accepts and processes paging bursts in accordance with an embodiment of the present disclosure.

Detailed Description

Embodiments of the present disclosure relate to reducing power consumption in GSM (Group System for mobile Communications) mobile devices and/or wireless terminals. More specifically, embodiments described herein may reduce power consumption of devices associated with decoding Paging Channel (PCH) downlink transmissions from base stations in a GSM environment. The PCH downlink transmission typically includes four paging bursts received from the base station. A mobile device (or each Subscriber Identity Module (SIM) in a mobile device supporting multiple SIMs) may be assigned more than one time slot in each of four paging bursts that include paging information directed to the mobile device. The PCH downlink transmission may be encoded using an 1/2 rate convolutional coding scheme in which data directed to a particular device is encoded across four paging bursts along with a Cyclic Redundancy Check (CRC) value for error checking. Accordingly, embodiments of the present disclosure allow for extraction of paging information encoded in a PCH downlink transmission by processing fewer than four paging pulses, thereby reducing power consumption of a mobile device when it receives a PCH downlink transmission.

Fig. 1 is a system diagram illustrating a portion of a cellular wireless communication system 100 supporting wireless terminals operating in accordance with the present invention. The cellular wireless communication system 100 includes a Mobile Switching Center (MSC) 101, a serving GPRS support node/serving EDGE support node (SGSN/SESN) 102, Base Station Controllers (BSCs) 152 and 154, and base stations 103, 104, 105, and 106. The SGSN/SESN 102 is coupled to the Internet 114 via a GPRS Gateway Support Node (GGSN) 112. A conventional voice terminal 121 is coupled to the PSTN 110. A voice over internet protocol (VoIP) terminal 123 and a personal computer 125 are coupled to the internet 114. The MSC 101 is coupled to a Public Switched Telephone Network (PSTN) 110.

Each of the base stations 103-106 serves a cell/zone group in which wireless communications are supported. The wireless link, which includes forward link and reverse link components, supports wireless communication between the base station and the wireless terminals it serves. These wireless links support digital data communications, VoIP communications, and other digital multimedia communications. The cellular wireless communication system 100 may also be backward compatible to support analog operation. The cellular radio communication system 100 supports the global system for mobile communications (GSM) standard and its enhanced data rates for GSM (or global) evolution (EDGE). The cellular wireless communication system 100 may also support GSM General Packet Radio Service (GPRS) evolution to GSM. However, the invention can also be applied to other standards, such as: TDMA standard, CDMA standard, etc. In general, the teachings of the present invention apply to digital communications incorporating automatic repeat request (ARQ) operations at the L2 layer, such as the LINK/MAC layer with variable decoding/decoding operations at the L1 layer (PHY).

The wireless terminals 116, 118, 120, 122, 124, 126, 128 and 130 are coupled to the cellular wireless communication system 100 via wireless links with the base stations 103 and 106. As shown, the wireless terminals may include cellular telephones 116 and 118, notebook computers 120 and 122, desktop computers 124 and 126, and data terminals 128 and 130. However, the cellular radio communication system 100 also supports communication with other types of radio terminals. As is generally known, devices such as notebook computers 120 and 122, desktop computers 124 and 126, data terminals 128 and 130, and cellular telephones 116 and 118 are capable of "surfing" the Internet 114, transmitting and receiving data communications such as e-mail, transmitting and receiving files, and performing other data operations. While the upload data rate requirements are not stringent, many of these data operations have significant download data rate requirements. Some or all of the wireless terminals 116, 130 are therefore capable of supporting the GPRS and/or EDGE operating standards while supporting the voice service portion of the GSM standard.

Fig. 2 is a block diagram functionally illustrating a mobile device 200 constructed in accordance with the present invention. The mobile device 200 of fig. 2 includes an RF transceiver 202, a baseband processor 206, a Central Processing Unit (CPU) 208, and various other components included within a chassis. The baseband processor 206 may perform physical layer processing including speech encoders/decoders, as well as other baseband functions that interact with the RF transceiver 202. In one embodiment, the baseband processor 206 may comprise a Digital Signal Processor (DSP). The CPU 208 may interact with data provided by the baseband processor 206 that characterizes the decoded information received via the RF transceiver 202, as well as with other systems and components in the mobile device 200, such as a display 220, a microphone 226, a speaker 228, a user input device 212, a camera 214, LEDs 222, and other components that may be incorporated into the mobile device as will be appreciated. The user input device 212 may include: a capacitive touch screen integrated within the display 220, a keyboard, other buttons or switches integrated into the mobile device 200, or any other user input device that may be understood.

Mobile device 200 may also include a battery 224 or other power source that may power the various components in the terminal. The terminal may also include more than one Subscriber Identity Module (SIM) port 213, flash RAM 216, SRAM 218, or other system resources. The mobile device 200 may also include one or more ports 210, which may include a Universal Serial Bus (USB) port and variants thereof (e.g., micro-USB, mini-USB, etc.), a proprietary (proprietary) port, or any other input/output port that may provide data manipulation and a power supply that may enable charging of the battery 224.

Fig. 3 shows various stages associated with forming and interpreting a Paging Channel (PCH) downlink transmission. The original page to an individual wireless terminal or mobile station is initially divided into a series of pages to be transmitted to the wireless terminal according to a predetermined schedule. This predetermined schedule causes individual wireless terminals to enter a sleep mode when there are no active transmissions and to wake up only when needed to receive their respective paging pulses. The wireless terminal is assigned a particular time slot in the paging burst that is extracted and processed to retrieve the device-related paging message. As shown, the original page undergoes two stages of encoding. First, the original page undergoes a block decoding operation, which is generally referred to as outer coding. The block coding stage allows for error detection within the data block. In addition, the data block may be supplemented with tail bits or a block code sequence. Since block decoding is the first or outer stage of channel decoding, block codes are also referred to as outer or outer coding schemes. Generally, two types of codes are used: cyclic Redundancy Check (CRC) or Fire Code. Fire codes allow for error correction or error detection. The connectivity is verified with error detection of fire codes.

The page then undergoes a second level of encoding, which is generally convolutional decoding called inner encoding. Alternatively, pages may be interleaved (interlave) to form paging bursts. These paging bursts are paging bursts received by the wireless terminal according to a predetermined schedule. Typically, four paging bursts constitute one paging message, and in many prior art implementations, all four or three paging bursts must be received before decoding begins.

To reduce power consumption of the mobile device 200 according to embodiments of the present disclosure, the baseband processor of the mobile device 200 may attempt to extract pages or encoded signals by processing less than four paging pulses. The paging message may be extracted from the signal encoded with a convolutional coding scheme (e.g., 1/2 rate convolutional code) in the paging burst by using a Viterbi (Viterbi) decoder. Thus, as the signal-to-noise ratio (SNR) of the received paging pulse increases, the probability of successfully extracting the encoded signal also increases.

Thus, if the SNR of the first and second paging bursts received in the paging message exceeds a given threshold, the baseband processor 206 of the mobile terminal may execute a Viterbi decoder and attempt to extract the paging message from the received first and second paging bursts. In this case, the baseband processor 206 may forego receiving the third and/or fourth paging bursts if the paging message is successfully extracted from the first and second paging bursts. In this way, the baseband processor 206 avoids the implications and losses of power consumption associated with receiving and/or processing the third and/or fourth paging bursts since the paging message is extracted without the third and fourth paging bursts. These implications of power consumption include the power required for activation of the RF transceiver 202 and reception of the third and/or fourth paging pulses, as well as for potentially performing analog-to-digital conversion of the signal and for any other RF operation that potentially consumes power.

The correctness of the extracted paging message can be verified by calculating a Cyclic Redundancy Check (CRC) code or other error check code for the extracted paging message and comparing the calculated value to the value embedded in the paging message itself. If not, the baseband processor 206 may then direct the RF transceiver 202 to receive a third paging pulse. The baseband processor 206 may then execute a viterbi decoder on the first, second, and third paging pulses in an attempt to extract the paging message. The baseband processor 206 may then perform an error check (e.g., compare the calculated error check value to the embedded value extracted from the decoded paging message) to determine whether the paging message was correctly extracted.

Thus, the present disclosure attempts to first extract a paging message using only the first and second paging bursts before receiving the third paging burst, and the power consumption associated with embodiments of the present disclosure may involve the following formula expressing the operations involved in receiving and decoding the paging message that consume power significantly. In the following formula, P_vIs the power consumption associated with the execution of a Viterbi decoder, P_bIs the power consumption associated with receiving paging bursts with the RF transceiver in the mobile device 200, and α is the probability that for a given SNR, page message extraction with only two paging bursts will fail:

(2P_b+P_v)(1-α)+α(3P_v+2P_v)

expression (2P)_v|P_v) (1 α) relates to the power consumption associated with receiving and processing two paging pulses to extract a paging message. Expression α (3P)_b+2P_v) To the power consumption associated with receiving and processing three paging bursts to extract a paging message when the error-checking code computed by the baseband processor 206 does not match the embedded error-checking code from the extracted paging message. In the latter case, the viterbi decoder is performed twice because after the failure associated with using only the first two paging bursts, it must be performed a second time to extract the paging message using the first paging burst, the second paging burst, and the third paging burst.

The power consumption associated with many prior art embodiments in which three paging pulses are received and used to extract a paging message may involve the following equation:

3P_b+P_v

as seen in the above formula, in the case where the extraction of the paging message fails with only two pulses, with a very low probability a, the power consumption associated with the embodiments of the present disclosure is lower than that of the previous technical embodiments. Such probabilities are generally low in high SNR environments. Thus, embodiments of the present disclosure may also assess the SNR of the first and second paging bursts to avoid the power consumption penalty associated with performing a viterbi decoder a second time with a third paging burst after failing to properly extract the paging message with only the first and second bursts. In other words, an SNR threshold may be employed and when the SNR of the first and second bursts exceeds the threshold, the baseband processor 206 may attempt to extract the paging message using only the first and second bursts, which, even if this extraction fails, may generate lower power consumption based on probability, particularly when the probability of failure is low.

Referring to fig. 4, a flow chart providing one example of the operation of the mobile device 200 according to various embodiments is shown. Alternatively, the flow chart of fig. 4 may be viewed as an implementation of various steps of a method of processing paging bursts associated with a paging channel by an RF transceiver, a baseband processor, and/or other components in the mobile device 200.

In block 401, the mobile device 200 may receive first and second pulses from a paging channel. In block 403, the baseband processor 206 may determine whether the SNR of the first paging pulse and the second paging pulse exceeds a threshold. In other words, the baseband processor 206 may determine whether the first and second pulses are received with a low noise level. The threshold may be related to a probability of failure to extract the paging message with the viterbi decoder using the first and second pulses for a given SNR value.

In block 405, the baseband processor 206 may initiate reception of a third paging pulse by the RF transceiver 202 of the mobile device 200 if the SNR of the first and second pulses does not exceed the threshold. In block 407, the baseband processor 206 may execute a viterbi decoder to extract the paging message, or decoded signal, using the first paging pulse, the second paging pulse, and the third paging pulse.

If the SNR of the first and second bursts exceeds the threshold in block 405, the baseband processor 206 performs viterbi decoding in an attempt to extract the paging message from the first and second paging bursts in block 409. In block 411, the baseband processor 206 determines whether the error-checking code embedded in the extracted data matches the error-checking code calculated by the baseband processor 206. Such error checking codes may include CRC codes. The mobile device 200 may then re-enter the sleep mode for a predetermined period of time until the next paging message is received.

It should be emphasized that the above-described embodiments of the present invention are merely possible examples of implementations, merely set forth for a clear understanding of the principles of the invention. Many variations and modifications may be made to the above-described embodiments of the invention without departing substantially from the spirit and principles of the invention. All such modifications and variations are intended to be included herein within the scope of this disclosure and the present invention and protected by the following claims.

Claims (10)

1. A wireless communications apparatus, comprising:

at least one Radio Frequency (RF) transceiver configured to receive a first encoded paging pulse and a second encoded paging pulse;

a baseband processor configured to:

identifying a first signal-to-noise ratio of the first encoded paging pulse;

identifying a second signal-to-noise ratio of the second encoded paging pulse;

when the first signal-to-noise ratio and the second signal-to-noise ratio exceed predetermined thresholds,

extracting a first encoded signal from the first encoded paging pulse and the second encoded paging pulse;

calculating an error check value associated with the encoded signal;

determining whether the error-checking value matches an embedded error-checking value decoded from the first encoded signal; and

initiating processing of a third encoded paging pulse when the error-checking value does not match the embedded error-checking value.

2. The system of claim 1, wherein the baseband processor is configured to extract the first encoded signal from the first encoded paging pulse and the second encoded paging pulse by executing a viterbi decoder.

3. The system of claim 1, wherein the baseband processor is further configured to:

initiating processing of a third encoded paging pulse when the error-checking value does not match the embedded error-checking value; and

extracting a second encoded signal from the first encoded paging pulse, the second encoded paging pulse, and the third encoded paging pulse.

4. The system of claim 1, wherein the baseband processor is further configured to:

initiating processing of a third encoded paging pulse when at least one of the first signal-to-noise ratio and the second signal-to-noise ratio does not exceed the threshold; and

extracting a second encoded signal from the first encoded paging pulse, the second encoded paging pulse, and the third encoded paging pulse.

5. A method performed in a wireless terminal for extracting a coded signal from a wireless signal, comprising the steps of:

receiving a first encoded paging pulse and a second encoded paging pulse;

identifying a first signal-to-noise ratio of the first encoded paging pulse;

identifying a second signal-to-noise ratio of the second encoded paging pulse;

extracting a first encoded signal from the first encoded paging pulse and the second encoded paging pulse when the first signal-to-noise ratio and the second signal-to-noise ratio exceed predetermined thresholds;

calculating an error check value associated with the encoded signal;

determining whether the error-checking value matches an embedded error-checking value decoded from the first encoded signal; and

initiating processing of a third encoded paging pulse when the error-checking value does not match the embedded error-checking value.

6. The method of claim 5, wherein extracting the first encoded signal from the first encoded paging pulse and the second encoded paging pulse further comprises: performing a Viterbi decoder on a designated time slot of the first encoded paging pulse and a corresponding designated time slot of the second encoded paging pulse.

7. The method of claim 5, further comprising the steps of:

initiating processing of a third encoded paging pulse when at least one of the first signal-to-noise ratio and the second signal-to-noise ratio does not exceed the threshold; and

extracting a second encoded signal from the designated time slots of the first encoded paging pulse, the second encoded paging pulse, and the third encoded paging pulse.

8. The method of claim 5, wherein the threshold is based at least in part on a probability that the error check value matches an embedded error check value decoded from the first encoded signal.

9. A system, comprising:

means for receiving a first encoded paging pulse and a second encoded paging pulse;

means for identifying a first signal-to-noise ratio of the first encoded paging pulse;

means for identifying a second signal-to-noise ratio of the second encoded paging pulse;

for when the first signal-to-noise ratio and the second signal-to-noise ratio exceed a predetermined threshold,

means for extracting a first encoded signal from said first encoded paging pulse and said second encoded paging pulse;

means for calculating an error check value associated with the encoded signal;

means for determining whether the error-checking value matches an embedded error-checking value decoded from the first encoded signal; and

means for initiating processing of a third encoded paging pulse when the error-checking value does not match the embedded error-checking value.

10. The system of claim 9, further comprising:

means for initiating processing of a third encoded paging pulse when the error-checking value does not match the embedded error-checking value; and

means for extracting a second encoded signal from the first encoded paging pulse, the second encoded paging pulse, and the third encoded paging pulse.