3G & 4G: LTE & WiMax

Plextek offers design services for the development of wireless products implementing the latest cellular communications standards. We develop terminals, test equipment and network equipment for our customers.

Now that 3G technology has achieved mainstream acceptance, the attention of product developers will move on to newer, emerging technologies. 4G is the next step in wireless communication providing an all IP based integrated system. The 4G standard includes a variety of wireless technologies including LTE, the Long Term Evolution program for 3G, and WiMax, the equivalent standard development for wireless broadband access, so flexibility in design will be important.  The challenge is that the radio channel is severely affected by signal dispersion, variable multipath delays and co-channel interference. Both LTE and WiMax use OFDMA/SCFDMA signalling, aggressive channelisation, adaptive modulation and Multiple-Input-Multiple-Output (MIMO) transceiver technology to provide a reliable service for mobile data access.

The specified  sub-carrier spacing is low and the modulation is a high order scheme. Therefore, the radio implementation must have excellent dynamic range, phase noise and adjacent channel performance: both for the transmit and receive subsystems. These factors place tough requirements on RF design, layout and integration: this is where Plextek’s long experience in all aspects of high performance radio system development can provide a complete solution.

Another challenge for cellular operators is interference management. Traditional approaches to cell planning need to adapt to the interference created by user installed pico and femtocell devices which require dynamic cell planning. Plextek can build on our experience of radio system simulation combined with real world propagation measurements to develop innovative solutions to interference management.

Building on past experience…

Plextek has considerable expertise in the design of both RF and baseband subsystems, ranging from low volume - high performance custom discrete designs to low cost - high volume solutions. Over the years we have produced designs for infrastructure, terminal equipment, technical trials and test equipment. In each case our design, layout and system integration skills help ensure robust operation and full EMC & product compliance.

Some examples include:

• High performance 400 MHz to 4GHz ‘software defined radio’ platform:
  • 400MHz to 4GHz tuning range
  • 20 MHz instantaneous BW (TX/RX)
  • High linearity (QAM, OFDM)
  • Low EVM and spectral regrowth
  • 1 Hz frequency steps
  • 0.1dB amplitude steps
• Compact portable equipment designs, where fast digital processing and a number of sensitive RF subsystems must co-exist on a single PCB.
• High capacity 16-QAM and 64-QAM DSP modems for point-point and mesh network systems.
• Propagation and coverage analysis for voice and data services – specifically impact femtocells the on macro network.
• WCDMA Layer 1 hardware/software
• WCDMA network monitoring equipment

Offering a complete solution…

Plextek’s experience of both RF and Baseband design, together with the ability to help specify detail requirements, makes us an ideal partner for anybody looking to either integrate an existing chipset solution or tackle a fully custom design. Please contact us.