Design considerations for a filter bank based TVWS transceiver

This paper discusses the design of a filter bank based transceiver capable of simultaneously up- or downconverting the entire TV white space (TVWS) frequency band. The spectral mask requirements favour a filter bank based approach, whereby RF sampling and the use of an FPGA for digital up- and down-conversion dictates a two-stage approach. Some of the design considerations, including filter design approaches, are discussed in this contribution

Efficient TV white space filter bank transceiver

Future devices operating in the TV white space (TVWS) spectrum will require to access different bands at different locations and times in order to avoid interference to incumbent users, requiring agility and sufficient spectral masks to satisfy regulators. Further, with very high-speed ADCs and DACs becoming reality, the purpose of this paper is to present a transceiver front-end capable of simultaneously up- and downconverting a significant portion of the UHF band. The proposed approach takes a two-stage filter-bank conversion for implementation on state-of-the-art FPGAs. We present three different parameterisations, which are compatible with the 40 TVWS channels between 470 and 790MHz in Europe, and compare them in terms of complexity and latency

Digital RF multiplexing for a TVWS transceiver implementation

Future devices operating in the TV white space (TVWS) spectrum will require to access different bands at different locations and times in order to avoid interference to incumbent users, requiring agility and sufficient spectral masks to satisfy regulators. In order to realise radio devices capable of this, we briefly review design efforts on a radio transceiver capable up- and downconverting the 40 8MHz TVWS channels residing between 470MHz and 790MHz. While we briefly address the overall proposed structure, the aim of this contribution is to address the practical issues of interfacing data conversion devices sampling at RF to state-of-the-art FPGAs which can then perform the digital operations required for up- and downconversion

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 operating at radio frequency (RF) have been proposed. The purpose of this paper is to demonstrate an implementation of such a transceivers at a scale-down frequency implemented on the OMAP--L137 evaluation module, whereby the RF link can be replaced by the device's audio I/O, thus enabling easier observation and algorithm testing for students

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

Cell culture manufacturing of accelerated projects - Lessons from life in the fast lane

The possibility of promising molecules receiving Breakthrough Therapy Designation (BTD) early in their clinical lifecycle encourages accelerated development strategies to decrease approval timelines. The speed that these projects move through the pipeline has required Genentech’s manufacturing organization to push the limits of their manufacturing flexibility in order to support a streamlined approach to scale-up. Recent accelerated development product manufacturing presented several new operational, logistical and technical challenges which required creative solutions to overcome, in order to achieve tight in-process control while maintaining agility. This poster will discuss the lessons learned by the manufacturing site while executing that Cell Culture manufacturing campaign, including The benefits and challenges associated with: Process qualification with limited small scale data Operating within a narrow design space Leveraging a clinical facility for process qualification activities Supporting new strategies in an existing facilit

Wideband TV white space transceiver design and implementation

For transceivers operating in television white space (TVWS), frequency agility and strict spectral mask fulfilments are vital. In the UK, TVWS covers a 320 MHz wide frequency band in the UHF range, and the aim of this paper is to present a wideband digital up- and down converter for this scenario. Sampling at radio frequency (RF), a two stage digital conversion is presented, which consists of a polyphase filter for implicit upsampling and decimation, and a filter bank-based multicarrier approach to resolve the 8MHz channels within the TVWS band. We demonstrate that the up- and down-conversion 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. An FPGA 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

The very young resolved stellar populations around stripped-envelope supernovae

The massive star origins for Type IIP supernovae (SNe) have been established through direct detection of their red supergiants progenitors in pre-explosion observations; however, there has been limited success in the detection of the progenitors of H-deficient SNe. The final fate of more massive stars, capable of undergoing a Wolf–Rayet phase, and the origins of Type Ibc SNe remain debated, including the relative importance of single massive star progenitors or lower mass stars stripped in binaries. We present an analysis of the ages and spatial distributions of massive stars around the sites of 23 stripped-envelope SNe, as observed with the Hubble Space Telescope, to probe the possible origins of the progenitors of these events. Using a Bayesian stellar populations analysis scheme, we find characteristic ages for the populations observed within 150 pc of the target Type IIb, Ib, and Ic SNe to be log (t) = 7.20, 7.05, and 6.57, respectively. The Type Ic SNe in the sample are nearly all observed within 100 pc of young, dense stellar populations. The environment around SN 2002ap is an important exception both in terms of age and spatial properties. These findings may support the hypothesis that stars with Minit > 30 M⊙ produce a relatively large proportion of Type Ibc SNe, and that these SN subtypes arise from progressively more massive progenitors. Significantly higher extinctions are derived towards the populations hosting these SNe than previously used in analysis of constraints from pre-explosion observations. The large initial masses inferred for the progenitors are in stark contrast with the low ejecta masses estimated from SN light curves