Ross Andrew Elliot

Partially reconfigurable TVWS transceiver for use in UK and US markets

With more and more countries opening up sections of unlicensed spectrum for use by TV White Space (TVWS) devices, the prospect of building a device capable of operating in more than one world region is appealing. The difficulty is that the locations of TVWS bands within the radio spectrum are not globally harmonised. With this problem in mind, the purpose of this paper is to present a TVWS transceiver design which is capable of being reconfigured to operate in both the UK and US spectrum. We present three different configurations: one covering the UK TVWS spectrum and the remaining two covering the various locations of the US TVWS bands.

Wideband TV White Space Transceiver Design and Implementation

For transceivers operating in television white space (TVWS), frequency agility and strict spectral mask fulfillments are vital. In the U.K., TVWS covers a 320-MHz-wide frequency band in the UHF range, and the aim of this brief is to present a wideband digital up- and downconverter for this scenario. Sampling at radio frequency (RF), a two-stage digital conversion is presented, which consists of a polyphase filter (PPF) for implicit upsampling and decimation, and a filter-bank-based multicarrier approach to resolve the 8-MHz channels within the TVWS band. We demonstrate that the up- and downconversion of 40 such channels is hardly more costly than that of a single channel. Appropriate filter design can satisfy the mandated spectral mask and control the reconstruction error. A field-programmable gate array implementation is discussed, capable of running the wideband transceiver on a single Virtex-7 device with sufficient word length to preserve the spectral mask requirements of the system.

TVWS filter bank transceiver on OMAP-L137 evaluation module

Communications devices operating in the TV white space (TVWS) spectrum will be strictly regulated, requiring compliance with spectral masks to protect incumbent users and sufficient frequency agility to allow access to numerous frequency bands at different times and locations. Therefore, future designs sampling directly at radio frequency (RF) have been proposed. The purpose of this paper is to demonstrate an implementation of such a transceiver at a scaled-down frequency implemented on the OMAP-L137 evaluation module, whereby the RF link can be replaced by the devices audio I/O, thus enabling easier observation and algorithm testing for students.