ChannelCore FlexThe ultimate radio receiver is capable of detecting and processing signals across all of the radio spectrum, all of the time. RF Engines Limited has taken a large step towards this goal with the introduction of an innovative and highly flexible, ultra-wideband, Channelizer IP core – the ChannelCore Flex.

ChannelCore Flex is a major breakthrough as it provides the customer with the ability to extract from a very wide input signal any number of channels simultaneously in real time. These can be any combination of different bandwidths and sampling rates with any overlap and centre frequencies. Furthermore, each channel can be individually defined and changed as required so that the system designer can tailor a solution that precisely meets the needs of the application on a single FPGA.

RFEL anticipates that the ChannelCore Flex will find widespread application in areas including Electronic Surveillance, satellite communications and future Base Station architectures, where simultaneous monitoring, detection and demodulation of a mixture of disparate communication channels, such as WiMax and GSM, using a single architecture are a definitive requirement.

“ChannelCore Flex delivers advanced features that are the culmination of over ten years of design and implementation experience and delivers the ability to do things that previously could not be done or required huge resources,” explained John Summers, RFEL’s CEO. “The pedigree of RFEL in the area of channelization means that there is a very low technical risk when embarking on a new design, so customers can be confident of being ‘up and running’ very quickly.”

Channelization is a relatively straight forward signal-processing task. For example, a Fast Fourier Transform (FFT) can efficiently process a wideband signal into over 1000 channels. However, this can only be done with limitations:
• The channels all have equal bandwidths, which is inflexible and problematic when processing different types of transmissions concurrently.
• The bandwidth of individual channels is inversely proportional to the number of channels supported.
• The centre frequencies of the channels are uniformly spaced and are not independently controllable.
• There is limited control of the frequency response of the individual channels, leading to compromised stop-band and pass-band performance.
• It cannot be readily interfaced to existing hardware due to differing sampling rates and data formats.

More advanced signal processing techniques, such as Weighted Over-Lap and Add (WOLA) pre-processing and hierarchical channelization using a Pipelined Frequency Transform (PFT), can overcome many of these limitations. RFEL has adopted these highly significant enhancements, along with other proprietary techniques, to create an ultra-wideband Channelizer that offers unrivalled performance and flexibility, enabling it to be tailored to bespoke applications while remaining very hardware efficient.

ChannelCore Flex is capable of being configured to support many thousands of channels, spanning an input bandwidth exceeding 1 GHz. Importantly, these channels can have individual bandwidths that can vary by several orders of magnitude, be overlapped to accommodate broadband transmissions, and have centre frequencies and sample rates that can be independently tuneable to sub-Hertz resolution ( 1Hz). The end result is a Channelizer architecture that can be configured to support concurrent monitoring of multiple channels, with bandwidths ranging from as large as hundreds of Megahertz, to as narrow as a few Hertz, delivering an overall aggregate channelized sample rate that can exceed 1Gs/s.

Feature Comparison Table

Feature / Requirement                                                                                  Old                                                                   RFEL 
                                                                                          FFT-based architecture                                   ChannelCore FLEX

1000s Channels     
                                                                  Yes                                                                     Yes

Individual Channel Bandwidth control                                 No                                                                     Yes

Individual Channel Bandwidth unaffected                                 No                                                                    Yes
by overall No. of channels supported

Flexibility in channel centre-frequency
                                        No                                                                   Yes

Individually controllable frequency response per channel             Very                                                 Yes 

Easy to interface to system                                              No                                                                     Yes

Unfortunately, there is no optimal, ‘one size fits all,’ Channelizer architecture, as each application places very different demands on the implementation. RFEL has resolved this problem by producing an IP core that is compile and run-time programmable from a simple set of parameters derived from the user’s technical specification. The end result is a high-performance and optimized IP core that has precisely the required level of flexibility demanded by the application, while minimising hardware cost and delivering a fast time-to-market.

Price & Availability
ChannelCore Flex is available for licensing now for implementation in a wide range of Xilinx or Altera FPGA devices. Supplied as a netlist, the IP is very compact so that low cost, medium sized FPGAs could be used. For example, a solution for a 200MHz input with 500 channels ranging from 5kHz to 5MHz would fit on a $100 device. Prices are dependent on each implementation’s specific set of requirements, but typically fall in the range of $10K - $40K.

RF Engines Ltd
RF Engines Limited (RFEL) is a leading UK-based electronic systems design company, providing high specification signal processing solutions for FPGAs, as well as supplying digital receiver and complete product solutions for the homeland security, defence, communications and instrumentation markets. Applications include communications base stations, satellite communications systems, test and measurement instrumentation, and bespoke wideband receivers/transceivers.