Archive : 13 May 2008 год

Atheros Communications announced a new member of its Radio-on-Chip for Mobile (ROCm) family of GPS solutions – a hardware and software GPS combination that targets mobile phones, Personal Navigation Devices (PNDs) and Personal Media Players (PMPs). The solution consists of the second-generation, single-chip GPS receiver, the AR1511, and companion ORION 3.0 software suite. This combination is suited for integrating advanced navigation functions into mobile devices, with state-of-the-art Assisted GPS (AGPS) technology, parallel search, and tracking sensitivity of -160dBm. The AGPS options speed navigation in challenging environments - indoors, in urban canyons and in other locations where broadcast satellite signals are obscured. AGPS can also accelerate the navigation process in conditions where broadcast ephemeris is available, by securing location information from non-broadcast sources, thus reducing power consumed in satellite search mode.

 Real-time ephemeris through cellular networks

Mobile networks can enable handsets with ephemeris data, satellite orbital information, more quickly than it can be downloaded directly from the satellites. The AR1511 and ORION 3.0 combo provides GSM handsets with AGPS, exceeding the industry-standard 3rd Generation Partnership Project (3GPP) specifications and the Secure User Plane for Location (SUPL) requirements, which facilitate communications between satellite location servers and GSM handsets. Bluetooth-enabled PNDs and PMPs can also access cellular-based ephemeris by connecting through a nearby handset.

 Real-time ephemeris through the Internet

 Atheros’ solution also provides conventional AGPS, access to real-time ephemeris over the Internet for PNDs, PMPs, and PCs -virtually any location-aware device that has Internet access over Wi-Fi. This allows GPS devices to have intermittent connectivity to real-time, Internet-accessed ephemeris when in the presence of a Wi-Fi access point, thus enabling accelerated location fixes, enhanced accuracy and reduced battery power.

 Extended Ephemeris when real-time access is unavailable

 Atheros’ AR1511 and ORION 3.0 combo also supports extended ephemeris, stored satellite orbital data, for any location-aware device. This feature leverages RX Networks GPStream technology to accelerate TTFF and reacquisition times with high location accuracy. Extended ephemeris can be downloaded using wired or wireless connections from Internet- or cellular-based servers. The data is stored and provides tracking ability for up to seven days, minimizing the device’s need to scan the sky or frequently access networks to obtain real-time location information. The GPStream technology delivers ephemeris in 2KB files versus solutions which employ bulky 40-50KB files.

 Further features

 The ROCm portfolio, consisting of mobile solutions for all AGPS connectivity modes, including GPS, Wi-Fi and Bluetooth, provides design and performance synergies to readily enhance the design process and user experience. The AR1511/ORION 3.0 combo features Atheros’ advanced parallel search, which utilizes eight search engines teamed with 12 highly sensitive tracking engines. This enhanced approach to search results in significant performance advantages – reducing reacquisition time by nearly half and increasing positional accuracy by more than 50 percent in challenging environments.

 The GPS solutions provide enhanced design flexibility with multiple options for either standalone or host-dependent applications. AR1511 is available in a 5mm x 5mm CSP for standalone and hosted configurations, or a 10mm x 10mm BGA package for standalone and hosted configurations on low-cost PCBs. AR1511F comes in a 7mm x 7mm BGA package with integrated DSP and stacked flash die for small form factor standalone configurations This AR1511F delivers GPS functionality without taxing the host processor and memory, and eliminates the need for dedicated Flash or fixed ROM. The chip provides significant advantages over competitive ROM-based solutions, with SDK support, selectable profiles and the ability to easily update software.

 Macronix is partnered with Atheros to provide the 1.8V, 8Mb MX29SL802CBXHI-90G flash option for standalone applications. The GPS solutions also employ worldwide satellite-based augmentation systems (SBAS). Systems supported by the ORION 3.0 software include WAAS (North America), MSAS (Japan), and EGNOS (Europe).

 Product Availability

 The AR1511 CSP package is pin-compatible to the uN3010 CSP package and provides a migration path from any existing design based on Atheros’ first-generation, single-chip GPS solution. The AR1511/ORION 3.0 will sample to customers in the second quarter of 2008.

 

For engineers requiring a PC based radar signal and antenna position capture card, the German manufacturer Spectrum provides the M2i.4038, which incorporates an ultra high speed 50 MSample/sec signal capture module coupled with a digital input module. Looking closer at the technical details, this card has three inputs available into the analogue section, these being signal input, external clock and external trigger. The card incorporates a high-resolution 14 bit A/D converter with excellent dynamic performance to ensure accurate radar signal recording. Sample clocking can be externally supplied from the users own equipment, or generated internally by the cards own clock engine utilising a low jitter on board oscillator. The trigger input connection also allows full control of the sampling window and an option to allow each trigger to be time-stamped.

 On the digital side of the M2i.4038 the azimuth encoder counter connection is very straight-forward just having 2 lines, one for the encoder pulse signal the other for a reset (North Reference Pulse). The cards pulse counter provides up to 16 bits of resolution, so with the capacity to record up to 65536 pulses on per rotation, this gives the opportunity to acquire with an exceptionally good positional accuracy. Another possibility is for the M2i.4038 to acquire data in parallel on 16 digital channels. This digital port wide capture can be used for antenna elevation as well as azimuth, though each would have to share the 16 bits. Counter input and parallel acquisition can also be individually combined by software command.

 In operation the radar card can be used in two ways. First there is the special multiple record option, where the trigger, either externally derived or from the arrival of the radar pulse, starts a recording window of finite length digitising the pulse and recording the angle positions at the end of the window. Using this mode of operation allows gaps in the recording at times when data is not required or unimportant. This reduces file sizes and bandwidth required for data transfer to the PC. Below is a timing diagram that exemplifies this: here the capture of the radar signal data occurs on the analogue channel. A second method is to run the capture continuously, with a radar pulse recorded along with angle positions on every clock pulse, which at 50 MSample/sec is a 20 nano second repeat period, (note that to suit your requirements this sampling rate may be varied).

 The card can be equipped with up to 2 GSample of on-board memory to cope with the large amounts of data. By choosing either the PCI 33/66 MHz (PCI-X) or PCI Express interface model, continuous data can be streamed to PC RAM, its potential capacity now greatly extended in the new 64 bit Windows and Linux environments. The radar card is also available in a lower cost 20 MSample/sec version, (model number M2i.4028), which still has all the features of the faster card, including the excellent support for Windows and Linux software environments (32 and 64 bit).

 The existing Spectrum drivers are used for programming the board, with the flexibility of the drivers allowing the programmer to build and design an application to exactly meet his requirements. A set of standard programming examples are provided to illustrate the boards main signal capture functions. Extensive support includes Visual C++, Borland C++, Gnu C++, Visual Basic, VB.NET, C#, J# and Delphi code. This special card comes with a 2-year manufacturer guarantee.