Method and arrangement for testing of components of a wireless communications system

The invention relates to an arrangement for testing Components of a wireless communication system having a Simulation computer and a test track.

The invention also relates to a method for testing Components of a wireless communication system, in which Data is sent and received on a test track and from the received data when compared to the transmitted data determined by a computer simulation, a test result becomes.

Components of a wireless communication system are all Software or hardware devices that connect directly to the communications are or indirectly involved. Each component thus takes Influence on the communication and regulates their quality. To the various factors of the individual components to detect in its overall function, it is necessary, this to test and evaluate the test results qualitatively.

A major part of components is arranged on the chip or in implements this, in particular in so-called on-chip systems.

In the case of chip development for communications technology through a plurality of stages, to a functional Prototype of the chip is present. The development is a lengthy process, especially with the increase of errors, not right, unpredictable cooperation of Components is fraught and so re-development cycles are necessary.

Generally, first a preliminary development in Block diagrams, the following is a simulation software. Even here occur many undetected errors. the present theoretical model follows the development of the hardware architecture and implementation to a prototype of a chip or chipset with software is present, then checked and is tested. The preparation of such a chip as Functional model is very expensive and time consuming. Hurry functional prototype are not multiple passes uncommon, resulting in a multiplication of costs.

Therefore, often prototype and demonstrator built, which with the functioning of the chip market Signal Processing Cards emulate.

Such signal processing cards, the digital Signal processors (DSP = Digital Signal Processor), or in Mixed forms with field-programmable gate arrays (FPGA = field programmable gate array) are populated can often only a represent small portion of the overall system.

win in the field of wireless communication systems Multi-antenna systems, so-called MIMO systems (MIMO = Multiple-Input Multiple-Output) becomes increasingly important. by means of such systems, it is possible the effective data throughput increasing and to minimize the bit error rate. to simulate a MIMO algorithm currently available signal processor boards, for deriving from the system Complexity, not suitable.

is a WO 03/069814 and US 2003/0236089 Simulator for mobile terminal devices (terminals) in known connection with a wireless network. there are base stations during a channel interference during Baseband processing tested. This solution is specifically designed to cellular communication networks designed, leading to an gradually developing prototypes for other wireless Communication systems unsuitable.

The invention is thus based on the object, a Ability to create, to various stages of development Components of a wireless communication system, which may also be a multi-antenna system to test realistically in order to avoid costly mistakes.

Assembly side, the object is achieved in that Test track includes a transmitter and a receiver, the constructed as electronic circuits and wirelessly are communicatively connected with each other and with Interfaces are provided that the standard computer hardware a personal computer is configured with standard interfaces and that the interface of the transmitter and the interface of are receiver connected to the standard interfaces.

With this solution, an, the simulation controlling and executable on a personal computer simulation software wireless communication systems simulation data on a Standard interface to a transmitter and a Receiver hardware transmit and receive. These are one or more connected antennas equipped and thus enabling an accurate data transmission the air. As standard interfaces, for example, USB or Firewire used.

In a particular embodiment of the invention, that the transmitter, an interface, a Signal processing unit with a memory and at least Elements for a transmit / receive channel, consisting of Digital / analogue converter, modulator, amplifier and antenna, and the receiver an interface, a signal processing unit with a memory and at least elements a Transmit / receive channel, consisting of antenna, amplifier, Demodulator and analog / digital converter comprising.

Both the transmitter and the receiver are connected to a signal processor for controlling a transmitting or Receiving channel provided that a memory connected is.

In a further embodiment of the invention it is provided that Transmitter and receiver for at least two Transmit / receive channels are formed to communicate.

A configuration of the transmitter and receiver with two or more transmit or receive channels is the ability the simulation of multi-antenna systems implemented.

In another embodiment of the invention it is provided that the signal processing unit of the transmitter and / or the Signal processing unit of the receiver a free programmable logic contains.

In another embodiment of the invention, that the signal processing unit of the transmitter and / or the signal processing unit of the receiver a digital Signal processor contains.

In a further embodiment of the invention it is provided that the signal processing unit of the transmitter and / or the Signal processing unit of the receiver a microprocessor contains.

In a further embodiment of the invention, that the signal processing unit of the transmitter and / or the signal processing unit of the receiver a (ASIC Aplication Specific Integrated Circuit) contains.

The signal processing unit of the transmitter may for example, by a user-programmable logic (FPGA Field-Programmable Gate Array), a digital signal processor (DSP = Digital Signal Processing), a microprocessor (MC = Microcontroller), an ASIC (Application Specific Integrated Circuits) or a combination of these Opportunities are formed.

In one embodiment of the invention it is provided that Transmitter and Receiver on each one or more separate PCBs are disposed.

In one embodiment of the invention it is provided that Transmitter and receiver to a common circuit board are arranged.

The hardware implementation of the transmitter and receiver module can share different on one or two isolated on PCB done. Thus, an adaptation of the Simulation hardware to different manufacturing and / or Customer requests are made.

The method, the object is achieved by the fact that the Standard computer hardware the data to be transmitted is generated and produced from these by means of a transmitter transmitting signals be that through an atmospheric transmission link sent and by a receiver as reception signals received and the standard computer hardware as received Data is passed.

For a simulation run a model of a wireless is Communication system using a simulation software, such as For example, "Matlab", "SIMULINK" or "Cocentric System Studio, "modeled. The in of the simulation software Simulation sequence data to be transmitted become a transmitted transmitter which made it distributes a broadcast signal generated. This transmitted signal may be in one or more Transmission channels, for example, for a multi-antenna system, be generated. The light emitted by the one or more antennas Transmission signal is a real transmission path (air) transmitted and of the one or more receiving antennas to a received simulation arrangement associated receiver. After a corresponding processing of the received signal in the receiver the received data of the simulation software are supplied and processed by the latter. As a result of this processing For example, a statement about the quality of Data transmission, characterized by the bit error rate to be hit.

In a particular embodiment of the invention, that the components to be tested at least partially in the Standard computer hardware can be simulated.

In a further embodiment of the invention it is provided that the components at least partially on the transmitter and / or Receiver hardware are implemented.

The inventive method enables the simulation run in various stages. In a first stage, the Simulation run only within the simulation software realized. In subsequent stages, the functions of the to create prototype step by step through the modeled flexibly scalable simulation and hardware tested. For example, in one stage of the simulation the transmission channel no longer simulated, but by a real transmitter antenna transmission line antenna receiver ready assembly and thus the later conditions corresponding simulation arrangement provided. After several simulation steps, where more and more functions be taken by the prototype hardware, thus arises a fully functional prototype.

In a further embodiment of the invention, that a personal computer as a standard computer hardware is used, the standard interfaces of the staff Computer be driven in such a way that a data exchange between transmitter and personal computers and between Receiver and personal computer through this Standard interfaces are provided.

The simulation software for the simulation of the wireless Communication system, for example, on a personal running computer. According to the prior art has this a set of standard interfaces, such as the parallele-, supports serial, USB and the Fireware interface. These interfaces may in the simulation be used to prototype hardware, for example, the transmitter, receiver and antenna assembly or Subassemblies consisting of these systems, with the staff to connect computers. Via this interface transmitted simulation data for hardware and received.

The invention provides a complete solution for the Overall system transmitter, receiver and transmission channel created. According to the invention is a complete hardware platform of flexible standard modules, so from DSPs and FPGAs, possibly also with ASICs (ASIC = Application Specific Integrated Circuit) or microcontroller or Microprocessor - if necessary - up.

With DSPs is the construction of a transmitter or receiver possible. The DSP is very flexible and programmable usable.

FPGAs have properties which those of CISP very are similar, but are similar to programmable DSPs. The implementations are often more efficient.

Transmitter and receiver consist of an analog part and a digital part. are about the interface units Transmitter and receiver with the Überstragungskanal simulated computer connected.

With hardware platform of the invention is from the beginning a hardware functional model close to reality in front. The platform has the property that it for Replica of the diverse developments in Communication technology is sufficiently flexible and Opportunities, in chip development, starting from the antenna side of the transmitter or receiver, progressively (Eg three algorithms blocks) the "safe", ideal Way completely faultless parts or blocks to a safe assigned portion of the hardware platform and this Area gradually continues to increase.

The advantages of the invention are<ul><li>a significant reduction in development time,</li><li>a substantial cost savings in the development of Communication devices,</li><li>the existence of a hardware-based model in the Hardware platform from the beginning of development and</li><li>in the possibility of a gradual development of Chips with secure, error-free subareas</li></ul>to see.

The invention will now by way of Embodiment are explained in detail. In the accompanying drawings shows<dl tsize="6"><dt>Fig. 1</dt><dd>a flow of a design flow in the design a wireless communication system according to the State of the art,</dd><dt>FIG. 2</dt><dd>a schematic representation of the preparation of Prototypes of components of wireless Communication systems using the invention,</dd><dt>Fig. 3</dt><dd>an inventive arrangement in the form of a Hardware platform,</dd><dt>Fig. 4</dt><dd>an inventive arrangement of a dual channel Card (SDCxC)</dd><dt>Fig. 5</dt><dd>an inventive arrangement of a MasterCard (SMC) and</dd><dt>Fig. 6</dt><dd>an inventive arrangement of a transmitter module (SRFC-Tx), a receiver assembly (SRFC-Rx) and a combined transmitter / receiver module (SRFC).</dd></dl>

As shown in Fig. 1, the development begins a wireless communication system in general with a Algorithm design stage, followed by a simulation software of the proposed algorithm. This allows a first estimate of the behavior under defined Test conditions.

Further steps of the design are the chip design addressed. After the prototype has been manufactured, the Examination and testing of the system are performed. This leads in most cases to a so-called re-design, when some features or requirements not achieved will. In practice, several re-designs are necessary, which to an increase in cost and in a delay in the Marketing leads.

Many redesigns resulting from defects within the first Algorithm design stage and the following simulation of the Algorithm. Such simulations are based, for example, on idealized assumptions and offer only an incomplete System view, compared with a real wireless Communication system. Thus some impacts not ideal system conditions are not or not fully be assessed. Examples for this are:<ul><li>The separate design of the baseband module and the RF module (RF module = analog RF Components) takes into account the effects of the two Assemblies nonconsecutive.</li><li>For the simulation of the signal propagation, a, from real propagation scenario deviant, channel model used. Thus, it comes at follow tests Prototype under real propagation conditions to Deviations for example in the Received signal quality and data transfer rate.</li><li>Through amendments to standards, to which Properties of the wireless communication system, For example, on the operating modes, effects, and Changes in manufacturing technology can the requirements between two design runs change.</li></ul>

The inventive method shown in Fig. 2, begins with the simulation of the wireless system and leads at the end of a working prototype. It shows the Problems already in the design phase of the algorithm and gives the designer the possibility of a prototype gradually to a flexible and scalable hardware platform to design and implement.

The first step allows the designers, simulated to transmit signals over an air interface, to these received and the simulation environment (the Simulation computer) due. This is in Fig. 2b shown. For such simulations can graph Design tools such as "Matlab" SIMULINK "or" Cocentric System Studio ", which for this application great flexibility will offer, used.

In the next step, more and more parts are the Algorithm, more and more physical layers (PHY = Physical Layer), the entire wireless system on the prototype transfer the hardware. Finally, this results in a fully working prototype. All baseband algorithms implemented on the hardware platform, as shown in Fig. 2c is shown. Thus, a comprehensive proof of concept the wireless communication system at an early phase the design process possible.

The designer can thus problems or errors which their have cause in real transmission conditions such as For example, channel transmission errors, RF impairments and impairments in real transmission channel already in recognize a very early stage of the design process and clear off.

The inventive hardware platform is as flexible as possible designed to give the system designer a large Z ahl to provide degrees of freedom available. Of the Transmitter 1 has the following parts:<ul><li>RF amplifier 4 (RF Power Amplifier (PA))</li><li>modulator 5</li><li>D / A converter 6</li><li>Digital signal processing hardware 7</li><li>Memory 8 and</li><li>Interface 9 for programming and data storage</li></ul>

The receiver 2 comprises the following parts:<ul><li>low-noise RF amplifier 10 (RF Low Noise Amplifier (LNA)) </li><li>demodulator 11</li><li>A / D converter 12</li><li>Digital signal processing hardware 7</li><li>Memory 8 and</li><li>Interface 9 for programming and data storage</li></ul>

The arrangement in the form of a hardware platform is connected to a standard computer hardware 13 connected, by simulating wireless Communication systems, in the simulation environment 3 allows. The standard interfaces 9, such as USB or Firewire, allow communication between the hardware platform and the computer simulation environment. 3

Fig. 3 shows the structure of the hardware platform together with a personal computer as a standard computer hardware 13 of the the simulation performs. The digital signal processing hardware 7 can either DSPs, FPGAs, ASICs, Microcontroller, or any combination of these elements consist.

The system architecture provides a scalable solution that the arrangement of multiple antennas at the transmitter 14 and 1 am Receiver 2 allowed.

The structure of the digital signal processing hardware 7 is varies depending on the claim or application. A advantageous solution consists in the connection of an FPGA and a DSP for signal processing. In one on this Concept coordinated programming of the simulation, the Advantages of both systems optimally utilized. These benefits consist for example in a FPGA in a high Data throughput at a bit for bit or word for word processing and a DSP in fitness for branched Algorithms and a block-processing of data.

An example of a to inventive solution consists of the Combination of a XILINX FPGAs and DSPs of a TigerSHAC Analog Devices Inc .. The parallel data processing is carried out after the SIMD principle (SIMD = Single Instruction Multiple Data) and enables a processing power of up to 4.8 GMACs / s with a core clock of 600 MHz. More Features of this solution are:<ul><li>24 Mbits of internal on-chip DRAM</li><li>14-channel DMA (Direct Memory Access) controller</li><li>integrated SDRAM controller and</li><li>Multiprocessor capability</li></ul>

Thus, such a DSP solution is very good for a suitable wireless communication hardware platform, since they sufficient processing power provides and for a Such a solution a wide range of fast Compiler tools and solutions for communications algorithms, among others, FFT, filtering tools and Viterbi decoder, for To be available.

Another reason for the use of such DSPs is its fast intercommunication and the multiprocessor ability up to four bidirectional ports and Ability in the DMA mode without derating for Processor core to work. The ports operate according to a DDR mode and extending up to 500 Mbyte / s per port and Transmission direction. The over all Connecting terminals resulting I / O bandwidth results in a, sufficient for wireless communication systems Data transfer rate of up to 4-Gbyte / s.

FPGA vendors offer solutions to integrate these Connecting terminals into their chips that fast a allow collaborations of FPGAs and DSPs.

One inventive solution is in the Figure 4, a dual Channel Card (SDCxC) shown. This card supports the Processing requirements on the physical layer of a wireless modem. All signal paths are bidirectional performed, Thus, the same card is either in the transmitter or used in the receiver part of the simulation hardware will. The capacity of the FPGA can according to the complexity of the Modems be staggered. This card allows either the Implementation of two transmitters, two receivers or Transmitter and a receiver (for bi-directional transmission). Further, an interface to an RF card (SRFC-Tx, SRFC-Rx) offered.

Another solution according to the invention is shown in FIG. 5, a Mastercard (SMC) is shown. This card provides additional Processor performance for sophisticated simulation algorithms (E.g. for MIMO systems), versions of higher layer functionalities or data Vorverarbeitungsprozessen. This is the SDCxC the link ports connected which in fast data transfer both directions permit. As well as the features of the SDCxC SMC bidirectional signal paths.

For digital to analog conversion, for analog to digital Conversion and for Hochrequenzteile (RF Transmitter / Receiver) the simulation hardware is a Combination of a transmitter assembly (SRFC-Tx = Radio Frequency Transmitter Card) and a receiver assembly (SRFC-Rx = Radio Frequency Receiver Card) used. In the contain transmitter / receiver modules shown Fig. 6 each of the A / D or D / A conversion and the Radio frequency part. The illustration in FIG. 6 shows each two transmitting and receiving channels.

The efficiency of the method of the data transfer rate between the simulation software and the simulation hardware dependent. Therefore, by the Method both rapid as to a slightly use and to-configure interface available posed. Modern assemblies such as FPGAs and DSPs can to the JTAG standard can be programmed. Therefore, the inventive signal processor card (SDCxC and SMC) with a JTAG interface equipped. Since the Data transfer rate of this interface is limited is for a fast data transfer from the personal computer to Simulation hardware and vice versa another interface 9 required. This is for example the PCI or VME parallel bus interface with a high bandwidth for the Data transfer realized.

Personal computers have standard interfaces such as 9 USB 2.0 and / or Firewire, which average at a Distance of data transfer a sufficient have data transfer speed. Therefore, the Signal processor cards invention (SDCxC and SMC) also with a USB 2.0 or FireWire interface equipped. The USB interface allows, for example, a data transfer rate up to 480 Mbit / s. The USB interface can also be the link between the Simulation Hardware and Software Simulation 3 (z. B. Matlab) manufacture.

In addition to these functions for data transmission within the simulation environment can 3 in the invention Process development tools (tools) within the Simulation with Matlab and Simulink are used. These Tools allow developers to identify and change the communication algorithms of simulation platform. So the developer can, for example, have an impact on Starting / setting options, the frequency and Time synchronization, the signal sequence-structure, the A / D and accept D / A conversion and the sampling rate in the conversion.

A growing number of standard communication algorithms also available for use on the fast simulation platform available, for example, the implementation of Standard modems. A basis for such algorithms Tools forms the "Xilinx System Generator", which the Simulate several DSP functions under Simulink and the a transmitting and shaping the structure directly corresponding FPGA chip allows. This tool is based on VHDL macros which designed for FPGA programming are and allow efficient FPGA design. At present, more and more tools for mapping DSP functionality, which are run under the Xilinx System, available.

<b>LIST OF REFERENCE NUMBERS</b>

<dl tsize="2" compact="compact"><dt>1</dt><dd>transmitter</dd><dt>2</dt><dd>receiver</dd><dt>3</dt><dd>simulation environment</dd><dt>4</dt><dd>High frequency amplifier (RF Power Amplifier (PA))</dd><dt>5</dt><dd>modulator</dd><dt>6</dt><dd>D / A converter</dd><dt>7</dt><dd>Digital signal processing hardware</dd><dt>8th</dt><dd>memory</dd><dt>9</dt><dd>interface</dd><dt>10</dt><dd>low-noise RF amplifier (RF Low Noise Amplifier (LNA))</dd><dt>11</dt><dd>demodulator</dd><dt>12</dt><dd>A / D converter</dd><dt>13</dt><dd>Standard computer hardware</dd><dt>14</dt><dd>antenna</dd></dl>