OFDM (LTE and WiMAX)
OFDMA is rapidly deposing WCDMA as the modulation scheme of choice for wideband air interfaces, and has been accepted by the IEEE for both the 802.11g Wireless LAN and the 802.16 WirelessMAN (aka WiMAX) radio standards, and by ETSI in two variants (OFDMA and SC-FDMA) for the downlink and uplink of the LTE radio standard. When used in combination with advanced smart antenna and MIMO techniques, the schemes together offer increased data rates and greater protection against fading than previous comparable radio systems.
PA’s Wireless Technology Practice has for many years offered a world-class service for rapid turnaround solutions in complex mixed-architecture radio platforms, implementing radio standards that have included GSM, EDGE, UMTS, EV-DO, HSDPA, and WiMAX. PA is now positioned to offer complete services for the development of radio systems based on both the OFDMA and SC-FDMA modulation schemes.
Typically these radio systems would employ multiple antennas at the base station, and increasingly at the user equipment. Features of a typical product or demonstration system could include:
- a system architecture suitable for standard-compliance
- complete software-defined platform with optimised baseband partition between DSP and FPGA
- custom radio
- point-to-point and point-to-multipoint transmission modes
- transmit diversity and spatial multiplexing MIMO techniques
- robust algorithms suited to multi-path fading environments
- cell search and acquisition procedures
- network-initiated and user-initiated calls, based on paging or random access protocols
- time and frequency tracking of the downlink signal in the CPE
- ranging and sounding signals for maintenance of uplink channels
- BER, RSSI and CINR measurements
- channel estimation and channel equalisation processing
- convolutional and turbo channel coding and decoding techniques
- external PC-based test and control applications software
- adaptive antenna aystem to enable capacity increases through SDMA.
The projects we undertake are frequently completed in challenging timescales and successfully integrate technologies from many different sources and suppliers. More.