JP2007534207A - Resource management in participating devices of a wireless communication network - Google Patents

Abstract

  A participation device of a wireless communication network is executed by a digital signal processing means for executing a plurality of digital signal processing operations on a communication signal received at the participation device or a communication signal transmitted from the participation device, and the digital signal processing means. A sequence schedule composed of a plurality of digital signal processing operations, a schedule specifying a time at which the sequence is executed, an update list consisting of updates that need to be applied to the schedule, A controller for determining the content of the update. The digital signal processing means is configured to check the update list for updates resulting from being applied to the schedule when each of the sequences is completed.

Description

  The present invention relates to a participation apparatus in a wireless communication network such as a base station or a mobile phone.

  The wireless communication network includes one or more subscriber units and one or more base stations for handling communications with the subscriber units. Each base station is typically capable of simultaneously processing multiple calls generated by multiple subscriber devices in the vicinity of the base station. Typically, the subscriber device is a mobile phone. A subscriber unit can also be referred to as a “user” of a base station.

  A modern base station typically performs some of its signal processing in the analog domain and some of its signal processing in the digital domain. For example, in the context of signal reception by a UMTS (Universal Mobile Telecommunications System) base station, analog signal processing typically involves down-conversion (low frequency conversion) of received RF (radio frequency) signals to baseband. At the same time, digital signal processing accompanied by restoration of the information signal from the baseband signal by descrambling or despreading is performed. In the context of signal transmission by the base station, digital signal processing typically involves spreading and scrambling the information signal, but with it, the resulting spread spectrum signal for transmission from the antenna. The analog signal processing is performed with the modulation on the RF carrier signal. The above description is clearly only the most concise overview of how signal processing operations are divided between the analog and digital domains, and there may be many variations. For example, part of the conversion between baseband and RF by digitally converting the signal between baseband and IF (intermediate frequency) and performing the conversion between IF and RF in the analog domain Can also be performed digitally.

  In a so-called 3G (third generation) wireless communication network, for example, a network conforming to the UMTS (Universal Mobile Telephone System) standard, a base station executes signals transmitted to a plurality of users and signals received from a plurality of users. The amount of digital processing that must be done can be a significant burden, especially when the number of users served by a base station is large. Significant efforts have been made to maximize base station throughput for multiple base stations and multiple subscriber devices in 3G networks.

  Traditionally, designs proposed for 3G base stations have multiple hardware specially designed to perform certain digital signal processing (and usually even baseband signal processing) tasks at high speed. Requires an element. However, conventional base station designs are programmed by appropriate software to perform multiple digital processing functions associated with the base station, including functions that would have been performed by multiple specially designed hardware elements. It is also possible to provide the base station with one or more fast general purpose signal processors that can be implemented. This type of base station is sometimes referred to as a soft base station. When such multiple general purpose signal processors are used in one soft base station, the multiple processors need to perform most of the base station baseband processing between them, so that the multiple processors Collectively, it is often referred to as a baseband processing resource of a soft base station.

  One object of the present invention is to provide an increase in the efficiency with which digital processing resources are used in participating devices of a wireless communication network such as a soft base station.

According to one aspect of the present invention, there is provided a wireless communication network participation apparatus, the participation apparatus comprising:
Digital signal processing means for performing a plurality of digital signal processing operations on a communication signal received at the participating device or a communication signal transmitted from the participating device;
A schedule of a sequence comprising a plurality of digital signal processing operations executed by the digital signal processing means, wherein the schedule specifies the time at which the sequence is executed;
An update list of updates that need to be applied to the schedule,
A controller for determining the content of the update,
The digital signal processing means is configured to check the update list for updates resulting from being applied to the schedule when each of the sequences is completed.

The present invention is also a method for controlling the execution of a plurality of digital signal processing operations within a participating device of a wireless communication network, the method comprising:
Accessing a schedule of sequences comprising a plurality of digital signal processing operations that need to be performed on signals received at or transmitted from the participating devices;
Executing a sequence of the plurality of digital signal processing operations that are scheduled to be executed at a current time;
At the end of the current sequence, checking the update list for updates that need to be applied to the schedule at the current time;
Updating the schedule with all updates that need to be applied at this time.

  Thus, the present invention performs updates to the schedule of multiple digital signal processing operations while reducing the interruption of the flow of multiple digital signal processing operations (which may need to be performed in real time). It can be so.

  The digital signal processing means and the controller are program codes executed on the data processing resources of the participating device, and the schedule and update list can be held in the data storage resource of the participating device. In such embodiments, the controller and digital signal processing means may be referred to as a controller task and a digital signal processing task, respectively.

  In a preferred embodiment, the participating device is a soft base station in a UMTS network.

  Hereinafter, an embodiment of the present invention will be described by way of example only with reference to the accompanying drawings.

  The UMTS soft base station 10 shown in FIG. 1 basically includes an RF unit 12 and a baseband unit 14. The purpose of the RF unit is to perform frequency conversion of signals while being transmitted between the baseband unit 14 and the antenna 16. The RF unit 12 down-converts the radio frequency (RF) signal received by the antenna 16 for processing by the baseband unit 14 and converts the baseband signal from the baseband unit 14 to the antenna. Up-convert (high frequency conversion) to an RF signal for transmission from 16. Although the base station 10 is a so-called soft base station, this means that substantially all of its baseband processing is performed in the digital domain using software. The baseband unit 14 includes a group of DSPs, a general-purpose microprocessor 22, and a memory system 24. Here, two of the group of DSPs are illustrated as 18 and 20. The purpose of the microprocessor 22 is to perform overall control over a plurality of functions of the base station. The plurality of DSPs perform a plurality of baseband signal processing operations that need to be performed on signals received from the RF unit 12 and signals sent to the RF unit 12. The types of baseband signal processing operations performed by multiple DSPs include code spreading and despreading, scrambling and descrambling, turbo coding, Viterbi coding, and so on.

  FIG. 2 illustrates how baseband signal processing is performed and controlled within the baseband unit 14 from the perspective of software running on multiple DSPs and microprocessors 22. The microprocessor 22 executes a base-band control (BBC) task 26 that is responsible for the overall control of baseband signal processing. In FIG. 2, the DSPs are represented by a DSP task 28 that is responsible for performing the required baseband digital signal processing tasks.

  The plurality of baseband digital signal processing tasks performed by the DSP task 28 are organized according to a task schedule 30 held in the memory 24. Schedule 30 includes a series of sequences, such as 32, consisting of multiple tasks of baseband digital signal processing. The schedule 30 specifies the time at which each of these sequences is to be executed. The start time of the task sequence of the schedule 30 is described as t0, t1, t2, t3, t4, t5, and t6 in FIG.

  The BBC task 26 is responsible for changing the contents of the schedule 30. The BBC task 26 maintains a list 34 of updates that need to be performed on the task schedule 30. The BBC task 26 runs on the microprocessor 22 and the microprocessor 22 can only communicate with the DSPs 18 and 20 via a simple message based interface. This makes it possible to separate asynchronous signal processing from synchronous signal processing. Therefore, the BBC task 26 cannot perform updates to the schedule 30 directly and depends on the action of the update list 34 to achieve this goal.

  Each entry in list 34 includes an update of schedule 30 and the time at which this update must be performed. A plurality of entries in the list 34 are given priority according to their designated execution times. Multiple updates in list 34 are applied to schedule 30 by DSP task 28. The DSP task 28 checks the list 34 at the end of processing for each sequence in the schedule to determine whether there are updates in the list 34 that need to be performed by the DSP task 28 at the current time. To do.

  An example of a system in operation is shown below.

  At time t0, the DSP task 28 accesses the schedule 30 as indicated by the arrow a. The DSP task 28 then proceeds to perform the baseband signal processing tasks specified in sequence 32 associated with time t0, as indicated by arrow b. After processing the last task 36 in sequence 32, DSP task 28 determines whether there is an update that needs to be performed on schedule 30 at this point, as indicated by arrow c. Then, the list 34 is checked. The update required at this point is performed as indicated by arrow d. As indicated by arrow e, the BBC task 26 adds an entry to the update list 34. The BBC task 26 is also responsible for sorting the plurality of entries in the list 34 so that priorities are given according to the time of execution assigned to the entries.

  In this way, the impact of processing that changes the schedule of multiple tasks of baseband signal processing on the performance of the tasks of baseband signal processing itself (which is often time-critical) is reduced. However, this is because changes to the schedule are performed only after a plurality of baseband signal processing tasks that need to be performed at a given time.

1 is a schematic diagram of a UMTS soft base station. FIG. It is the schematic explaining the signal processing task management method used in the base station of FIG.

Claims (6)

A wireless communication network participation device,
Digital signal processing means for performing a plurality of digital signal processing operations on a communication signal received at the participating device or a communication signal transmitted from the participating device;
A schedule of a sequence comprising a plurality of digital signal processing operations executed by the digital signal processing means, wherein the schedule specifies the time at which the sequence is executed;
An update list of updates that need to be applied to the schedule,
A controller for determining the content of the update,
The digital signal processing means is configured to check the update list for updates resulting from being applied to the schedule when each of the sequences is completed. A method for controlling execution of a plurality of digital signal processing operations within a participating device of a wireless communication network, comprising:
Accessing a schedule of sequences comprising a plurality of digital signal processing operations that need to be performed on signals received at or transmitted from the participating devices;
Executing a sequence of the plurality of digital signal processing operations that are scheduled to be executed at a current time;
At the end of the current sequence, checking the update list for updates that need to be applied to the schedule at the current time;
Updating the schedule with all updates that need to be applied at this time.   The participation apparatus according to claim 1, wherein the digital signal processing means and the controller each include software executed on a data processing resource of the participation apparatus.   The program code which makes a data processor perform the method of Claim 2.   A participating device of a wireless communication network, substantially as described herein with reference to FIGS. A method for controlling the execution of a plurality of digital signal processing operations within a participating device of a wireless communication network, substantially as described herein with reference to FIGS.

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