This year, the DRM booth was much smaller than last year, DRM presentations from the DRM consortium have been reduced to just a small part of the digital radio booth. Nevertheless, several receivers were shown and could also be listened to. Under a metal roof, with another exhibition floor above and and with a huge number of interference sources like plasma and LCD TVs all around the trade fair, shortwave reception was nearly impossible without an external antenna. Thus, the DRM booth had its own active antenna on the roof and a few of the receivers were connected to this antenna.
Roberts MP-40 receiver
The now already well-known Roberts MP-40 receiver was demonstrated and seemed to deliver quite reliable reception. However, the mediumwave ferrite antenna that can be connected to the MP-40 via the lower 5 pin-connector on the left side of the receiver was not shown. The external, roof-mounted active (ie amplified) antenna was connected to the MP-40 through a 6 dB attenuator, perhaps to reduce the risk of intermodulation or to improve power sharing among the various receivers connected to the same antenna. I did not ask for a definitive release date for the MP-40.
Morphy Richards receiver
The new Morphy Richards DRM receiver was also shown. Since it doesn't come with an external antenna connector, the telescopic antenna had been removed and had been replaced by an improvised cable connection to the aforementioned external antenna. The receiver's connectors are located on the rear side. A slot accepting SD memory cards for recording and playback is also available on the receiver's left side. There seemed to be a problem with the improvised antenna connector since reception was not very reliable.
It must be noted, that it was difficult to judge audio performance of the receivers, since the acoustic noise level in the hall was rather high and it was even more increased by a band that was playing just across the aisle opposite the DRM booth.
Himalaya DRM2008 and DRM2009 receivers
Two new prototype receivers from Himalaya, a company based in Hongkong, with manufacturing in Shengzen, China, were shown. They are the DRM2008 and the DRM2009. The latter was demonstrated in two versions, a model in a black and one in a white case but with identical controls.
This photo shows all three receivers. The DRM2008 is in the centre, it is based on a design featuring an Analog Devices Blackfin (R) DSP unit. This receiver is a follow-up on the DRM2010 shown at IFA last year. DRM decoder software inside the receiver is based on code obtained from the BBC, further software development is in part carried out by a division of Analog Devices based in India. The DRM decoder is using integer arithmetics. Here is another picture of the DRM2008 receiving Deutschlandfunk on mediumwave 855 kHz. The DRM2008 is controlled via push buttons, this picture shows the display. No antenna connector is provided on any of the receivers except the Roberts MP-40, and the DRM 2009 had to be fitted with an extra, small headpone-type plug mounted provisionally in the rear of the case.
When asked for a possible release date, a representative from Himalaya would refuse to give a date due to the uncertainties involved. It was emphasised that the receivers are still in the development phase and that there are still a few points (aside from not being labeled as a receiver but a "reciever"
) where they have to be improved upon.
The other Himalaya receiver, the DRM2009, shown here in both the black and the white case with the SD card slot clearly visible on the left side of the receiver, is based on the Radioscape RS-500 module. The RS-500 module itself, which is also built into the Roberts MP-40 and the Morphy Richards DRM receiver, was also shown. It could be noticed that the F-connector for the antenna input is no longer mounted directly onto the board, which would make the module connection susceptible to breaking in case of too much force on the antenna connector. Instead, a coaxial cable ending in a coaxial connector is now provided.
All Himalaya receivers come with a nice handle which folds back nicely into the case of the receiver when not needed. This picture shows the handle folded out into carrying position. All Himalaya receivers are fitted with an SD card slot for recording received programmes and play back of this and other content eg MP3 files which may be stored on the card. A playlist is displayed during replay from the SD card. I think, I should have listened to the DRM recording from 1858.
In this picture, the DRM2009 is shown receiving a local mediumwave DRM broadcast on its built-in ferrite antenna. Also have a look at the rear side of the receiver with the battery compartment closed and opened.
Besides the SD card slot, all Himalaya receivers also come with an USB connector, an external headphone plug, an external power socket and they all feature a recessed Reset button as shown in this picture.
The largest drawback of all the receivers shown at the DRM booth is battery consumption. Battery drain on these receivers is rather high, so even alkaline batteries will last only perhaps two or three hours when a DRM station is being received.
Given the conditions inside the hall and the lack of an external antenna connection on some of the receivers, reception performance could not really be judged. However, occasional reception on shortwave was nevertheless possible even on the receivers' telescopic antennae.
The Fraunhofer concept
A major drawback of all the previously mentioned receivers and receiver prototypes is their high current consumption. Since the required mathematical operations are mostly carried out in sequence one after the other, the processor executing these functions has to run at a rather high clock speed. Well, clock speed on the specialised DSPs doesn't have to be as high as on a general-purpose PC running the DRM software or Dream but it is still remarkably high for a portable device and will result in high power consumption and high battery drain.
Developers at the Fraunhofer Institute for integrated circuits in Erlangen, Germany have therefore developed a new DRM decoder, in which the required functions are more or less carried out in parallel and where logic circuits have been hard-wired to carry out the required vector operations. Currently, this design is built using two programmable logic arrays to demodulate the OFDM signal and one ARM processor (a widely used third party processor core) to decode the DRM audio and data services.
This circuit board of the decoder contains two such programmable logic arrays (labeled XILINX) and the ARM processor (labeled ALTERA). The rest of the circuit board comprises peripheral circuits and memory chips. Everything is running at a clock speed of 10 MHz only. Since the logic circuits have been developed using state-of-the-art tools, all the logic wiring is available in a format which can easily be used as a building block library in the design of a dedicated integrated circuit using a silicon compiler. The ARM processor, widely used in mobile phones and other portable devices, is also available as such a library.
The board shown is just an experimental way of putting the circuit to work. In its final version, the whole unit will more or less occupy a few square millimetres on a silicon chip and it can be easily implemented into modern radio receiver concepts. Development is carried out as a joint effort of the Fraunhofer Institute for integrated circuits, ST Microelectronics (a world-renowned semiconductor manufacturer) and Kenwood, a car radio manufacturer. The prototype receiver shown at IFA is fed with A/D converted I/Q IF signals from a car radio using a current design based on an ST Microelectronics chipset.
Kenwood was also showing this prototype but it could not be demonstrated due to lack of an external antenna available at the Kenwood booth. The prototype is already integrated into the current user interface.
In my view, the Fraunhofer concept looks most promising and it opens a way to mass-produced cheap DRM receivers which will only consume a moderate amount of power.
Thanks for your attention and also thanks to Simone for hosting my pictures on her webserver. Copyright is retained on all pictures. Pictures from this report may only be linked to or used on other webpages if a link to this entire post is given.
Roland
Roberts MP-40 receiver
The now already well-known Roberts MP-40 receiver was demonstrated and seemed to deliver quite reliable reception. However, the mediumwave ferrite antenna that can be connected to the MP-40 via the lower 5 pin-connector on the left side of the receiver was not shown. The external, roof-mounted active (ie amplified) antenna was connected to the MP-40 through a 6 dB attenuator, perhaps to reduce the risk of intermodulation or to improve power sharing among the various receivers connected to the same antenna. I did not ask for a definitive release date for the MP-40.
Morphy Richards receiver
The new Morphy Richards DRM receiver was also shown. Since it doesn't come with an external antenna connector, the telescopic antenna had been removed and had been replaced by an improvised cable connection to the aforementioned external antenna. The receiver's connectors are located on the rear side. A slot accepting SD memory cards for recording and playback is also available on the receiver's left side. There seemed to be a problem with the improvised antenna connector since reception was not very reliable.
It must be noted, that it was difficult to judge audio performance of the receivers, since the acoustic noise level in the hall was rather high and it was even more increased by a band that was playing just across the aisle opposite the DRM booth.
Himalaya DRM2008 and DRM2009 receivers
Two new prototype receivers from Himalaya, a company based in Hongkong, with manufacturing in Shengzen, China, were shown. They are the DRM2008 and the DRM2009. The latter was demonstrated in two versions, a model in a black and one in a white case but with identical controls.
This photo shows all three receivers. The DRM2008 is in the centre, it is based on a design featuring an Analog Devices Blackfin (R) DSP unit. This receiver is a follow-up on the DRM2010 shown at IFA last year. DRM decoder software inside the receiver is based on code obtained from the BBC, further software development is in part carried out by a division of Analog Devices based in India. The DRM decoder is using integer arithmetics. Here is another picture of the DRM2008 receiving Deutschlandfunk on mediumwave 855 kHz. The DRM2008 is controlled via push buttons, this picture shows the display. No antenna connector is provided on any of the receivers except the Roberts MP-40, and the DRM 2009 had to be fitted with an extra, small headpone-type plug mounted provisionally in the rear of the case.
When asked for a possible release date, a representative from Himalaya would refuse to give a date due to the uncertainties involved. It was emphasised that the receivers are still in the development phase and that there are still a few points (aside from not being labeled as a receiver but a "reciever"
) where they have to be improved upon.The other Himalaya receiver, the DRM2009, shown here in both the black and the white case with the SD card slot clearly visible on the left side of the receiver, is based on the Radioscape RS-500 module. The RS-500 module itself, which is also built into the Roberts MP-40 and the Morphy Richards DRM receiver, was also shown. It could be noticed that the F-connector for the antenna input is no longer mounted directly onto the board, which would make the module connection susceptible to breaking in case of too much force on the antenna connector. Instead, a coaxial cable ending in a coaxial connector is now provided.
All Himalaya receivers come with a nice handle which folds back nicely into the case of the receiver when not needed. This picture shows the handle folded out into carrying position. All Himalaya receivers are fitted with an SD card slot for recording received programmes and play back of this and other content eg MP3 files which may be stored on the card. A playlist is displayed during replay from the SD card. I think, I should have listened to the DRM recording from 1858.
In this picture, the DRM2009 is shown receiving a local mediumwave DRM broadcast on its built-in ferrite antenna. Also have a look at the rear side of the receiver with the battery compartment closed and opened.
Besides the SD card slot, all Himalaya receivers also come with an USB connector, an external headphone plug, an external power socket and they all feature a recessed Reset button as shown in this picture.
The largest drawback of all the receivers shown at the DRM booth is battery consumption. Battery drain on these receivers is rather high, so even alkaline batteries will last only perhaps two or three hours when a DRM station is being received.
Given the conditions inside the hall and the lack of an external antenna connection on some of the receivers, reception performance could not really be judged. However, occasional reception on shortwave was nevertheless possible even on the receivers' telescopic antennae.
The Fraunhofer concept
A major drawback of all the previously mentioned receivers and receiver prototypes is their high current consumption. Since the required mathematical operations are mostly carried out in sequence one after the other, the processor executing these functions has to run at a rather high clock speed. Well, clock speed on the specialised DSPs doesn't have to be as high as on a general-purpose PC running the DRM software or Dream but it is still remarkably high for a portable device and will result in high power consumption and high battery drain.
Developers at the Fraunhofer Institute for integrated circuits in Erlangen, Germany have therefore developed a new DRM decoder, in which the required functions are more or less carried out in parallel and where logic circuits have been hard-wired to carry out the required vector operations. Currently, this design is built using two programmable logic arrays to demodulate the OFDM signal and one ARM processor (a widely used third party processor core) to decode the DRM audio and data services.
This circuit board of the decoder contains two such programmable logic arrays (labeled XILINX) and the ARM processor (labeled ALTERA). The rest of the circuit board comprises peripheral circuits and memory chips. Everything is running at a clock speed of 10 MHz only. Since the logic circuits have been developed using state-of-the-art tools, all the logic wiring is available in a format which can easily be used as a building block library in the design of a dedicated integrated circuit using a silicon compiler. The ARM processor, widely used in mobile phones and other portable devices, is also available as such a library.
The board shown is just an experimental way of putting the circuit to work. In its final version, the whole unit will more or less occupy a few square millimetres on a silicon chip and it can be easily implemented into modern radio receiver concepts. Development is carried out as a joint effort of the Fraunhofer Institute for integrated circuits, ST Microelectronics (a world-renowned semiconductor manufacturer) and Kenwood, a car radio manufacturer. The prototype receiver shown at IFA is fed with A/D converted I/Q IF signals from a car radio using a current design based on an ST Microelectronics chipset.
Kenwood was also showing this prototype but it could not be demonstrated due to lack of an external antenna available at the Kenwood booth. The prototype is already integrated into the current user interface.
In my view, the Fraunhofer concept looks most promising and it opens a way to mass-produced cheap DRM receivers which will only consume a moderate amount of power.
Thanks for your attention and also thanks to Simone for hosting my pictures on her webserver. Copyright is retained on all pictures. Pictures from this report may only be linked to or used on other webpages if a link to this entire post is given.
Roland
Comment