U.S. patent application number 11/321977 was filed with the patent office on 2006-10-26 for dual mode radio frequency reception device and corresponding multimedia receiver.
This patent application is currently assigned to Fahrenheit Thermoscope LLC. Invention is credited to Eric Andre, Patrick Senn.
Application Number | 20060240793 11/321977 |
Document ID | / |
Family ID | 9543658 |
Filed Date | 2006-10-26 |
United States Patent
Application |
20060240793 |
Kind Code |
A1 |
Andre; Eric ; et
al. |
October 26, 2006 |
Dual mode radio frequency reception device and corresponding
multimedia receiver
Abstract
The invention relates to a dual mode radio frequency reception
device of the type enabling the reception firstly of multi-carrier
broadcast signals in a first frequency band and secondly radio
positioning signals in a second frequency band, comprising a single
preprocessing module (21), particularly including a pass-band
antenna filter (211) in which the pass-band includes at least the
said first and second frequency bands, and outputting firstly to a
first processing system (22) to process the said multi-carrier
broadcast signals, and secondly to a second processing system (23)
to process the said radio positioning signals.
Inventors: |
Andre; Eric; (Grenoble,
FR) ; Senn; Patrick; (Grenoble, FR) |
Correspondence
Address: |
MEYERTONS, HOOD, KIVLIN, KOWERT & GOETZEL, P.C.
700 LAVACA, SUITE 800
AUSTIN
TX
78701
US
|
Assignee: |
Fahrenheit Thermoscope LLC
|
Family ID: |
9543658 |
Appl. No.: |
11/321977 |
Filed: |
December 29, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
09511330 |
Feb 23, 2000 |
6999716 |
|
|
11321977 |
Dec 29, 2005 |
|
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Current U.S.
Class: |
455/207 ;
455/205 |
Current CPC
Class: |
H04H 2201/20 20130101;
H04H 40/18 20130101; G01S 19/36 20130101 |
Class at
Publication: |
455/207 ;
455/205 |
International
Class: |
H04B 1/16 20060101
H04B001/16 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 23, 1999 |
FR |
99 03769 |
Claims
1-9. (canceled)
10. A dual mode radio frequency reception device comprising: a
single preprocessing module configured to receive digital audio
broadcast (DAB) signals in a first frequency band, and global
positioning system (GPS) signals in a second frequency band,
wherein the preprocessing module includes a pass-band antenna
filter having a pass-band that includes at least the first and the
second frequency bands; wherein the preprocessing module is
configured to substantially simultaneously output the DAB signals,
and the GPS signals; a first processing system coupled to the
preprocessing module and configured to process the DAB signals; and
a second processing system coupled to the preprocessing module and
configured to process the GPS signals substantially simultaneously
as the processing of the DAB signals.
11. The device as recited in claim 10, wherein the single
preprocessing module includes: a first low noise amplifier coupled
to receive the DAB signals and the GPS signals; a first
transposition stage coupled to the first low noise amplifier and
configured to generate a first intermediate frequency, by
multiplying by a first transposition frequency.
12. The device as recited in claim 11, wherein the first processing
system includes a second transposition stage coupled to receive the
DAB signals and to generate a second intermediate frequency by
multiplying by a second transposition frequency.
13. The device as recited in claim 12, wherein the second
processing system includes a third transposition stage coupled to
receive the GPS signals and to generate a third intermediate
frequency by multiplying by a third transposition frequency.
14. The device as recited in claim 13, further comprising a
frequency synthesizer coupled to the preprocessing module, the
first processing system, and the second processing system, wherein
the frequency synthesizer is configured to generate from a
reference frequency, a plurality of frequencies comprising: an
analog-digital conversion frequency; the first transposition
frequency; the second transposition frequency; and the third
transposition frequency.
15. The device as recited in claim 14, wherein the first processing
system comprises a first digitization means and the second
processing system comprises a second digitization means, wherein
the first and the second digitization means are each controlled by
the analog-digital conversion frequency.
16. The device as recited in claim 15, wherein the first
digitization means includes a delta-sigma pass-band modulator.
17. The device as recited in claim 15, wherein the second
digitization means includes a "1-bit" quantifier.
18. The device as recited in claim 10, wherein the first frequency
band comprises the range of frequencies between 1452.192 MHz and
1491.392 MHz, and the second frequency band comprises the range of
frequencies between 1574.42 MHz and 1576.42 MHz.
19. The device as recited in claim 10, wherein the DAB signals
comprise audio, video, and text.
20. A multimedia receiver system comprising: a display unit; and a
dual mode radio frequency receiver configured to receive digital
audio broadcast (DAB) signals and global positioning system (GPS)
signals, wherein the dual mode radio frequency receiver includes: a
single preprocessing module configured to receive the DAB signals
in a first frequency band, and the GPS signals in a second
frequency band, wherein the preprocessing module includes a
pass-band antenna filter having a pass-band that includes at least
the first and the second frequency bands; wherein the preprocessing
module is configured to substantially simultaneously output signals
corresponding to the DAB signals, and the GPS signals; a first
processing system coupled to the preprocessing module and
configured to process signals corresponding to the DAB signals; and
a second processing system coupled to the preprocessing module and
configured to process signals corresponding to the GPS signals
substantially simultaneously as the processing of signals
corresponding to the DAB signals; wherein the display unit is
configured to display a geographic map generated from information
received via the DAB signals, wherein the map includes an
indication corresponding to a current geographic location of a user
operating the multimedia receiver system, wherein the indication is
generated from the GPS signals.
21. A method comprising: receiving via a single preprocessing
module including a pass-band antenna filter having a pass-band that
includes at least a first frequency band and a second frequency
band, digital audio broadcast (DAB) signals in the first frequency
band, and global positioning system (GPS) signals in the second
frequency band; substantially simultaneously outputting the DAB
signals, and the GPS signals; processing the DAB signals; and
processing the GPS signals substantially simultaneously as the
processing of the DAB signals.
22. The method as recited in claim 21, further comprising receiving
the DAB signals and the GPS signals via a first low noise amplifier
of the single preprocessing module; and generating at a first
transposition stage a first intermediate frequency, by multiplying
the DAB signals and the GPS signals by a first transposition
frequency.
23. The method as recited in claim 22, further comprising receiving
the first intermediate frequency including the DAB signals and
generating at a second transposition stage a second intermediate
frequency by multiplying the first intermediate frequency by a
second transposition frequency.
24. The method as recited in claim 23, further comprising receiving
the first intermediate frequency including the GPS signals and
generating a third intermediate frequency at a third transposition
stage by multiplying the first intermediate frequency by a third
transposition frequency.
25. The method as recited in claim 21, wherein the first frequency
band comprises the range of frequencies between 1452.192 MHz and
1491.392 MHz, and the second frequency band comprises the range of
frequencies between 1574.42 MHz and 1576.42 MHz.
26. The method as recited in claim 21, wherein the DAB signals
comprise audio, video, and text.
Description
[0001] The domain of this invention is multimedia receivers, and
particularly portable receivers. More precisely, the invention
relates to receivers capable of receiving firstly multi-carrier
broadcast signals, and secondly radio positioning signals.
[0002] This type of multimedia receiver has been developed
particularly within the framework of the European MEDEA A222
"Components for portable multimedia systems" project. This type of
receiver is planned to include firstly DAB (Digital Audio
Broadcasting) signal reception means, and secondly GPS (Global
Positioning System) signal reception means.
[0003] The DAB system is a digital data broadcasting system, the
first purpose of which was to replace the current FM radio. One of
the objectives was then to offer improved sound quality, referred
to as "digital" and accompanied by text information.
[0004] The DAB system uses COFDM modulation. According to the
standard currently used, its spectrum occupies 23 channels
distributed on a 39.2 MHz frequency band. The width of a DAB
channel is 1.536 MHz, and the spacing between channels is 176 kHz.
The reception level varies between -90 dBm and +8 dBm.
[0005] Each DAB channel is surrounded by adjacent channels, the
level of which may be 40 dB above the useful channel, or even 70 dB
for remote channels (I/C=40 dB to 70 dB). The range of the input
signal, and the presence of adjacent channels, make the use of
controlled gain amplifiers (CGA) and selective filters necessary.
An analog-digital converter with a sufficiently wide range could
reduce the constraints on the first two parameters through the use
of digital filters and CGAs that are easier to make. The receiver
must be sufficiently selective to extract the useful signal, and
the range must be sufficiently wide to accept variations in the
reception signal.
[0006] In particular, the following documents describe examples of
DAB receivers: [0007] Ward Titus, Rosa Croughwell, Chris Schiller,
Larry DeVito, "A Si BJT Dual Band Receiver IC for DAB", Radio
Frequency Integrated Circuits Symposium, 1998, pp. 297-300; [0008]
Marc Goldfarb, Rosa Croughwell, Chris Schiller, Darell Livezey,
George Heiter, "A Si BJT IF Down Converter/AGC IC for DAB", Radio
Frequency Integrated Circuits Symposium, 1998, pp. 305-308; [0009]
M. Bolle, K. Gieske, F. Hoffmann, T. Mlasko, G.
[0010] Spreitz, "D-FIRE: A DAB Receiver System on a Chip",
Proceedings of ESSCIRC'98, 1998, pp. 360-363.
[0011] A DAB receiver can receive audio, video and/or text type
data, such that it performs the functions of a multimedia
terminal.
[0012] The addition of other services such as the GPS system makes
it possible to develop other interesting applications.
[0013] Thus, reception of a GPS signal in order to precisely
determine the location of the receiver, is a means of directly
developing navigation assistance applications, with the multimedia
terminal informing the user of his position on a geographic map
downloaded through the DAB channel. Within the framework of an
automobile application, the DAB broadcast can provide information
about traffic jams and accidents. Positioning using GPS is a means
of determining a new route.
[0014] It should be noted that the GPS signal uses spectrum
spreading modulation.
[0015] Two types of GPS signals are emitted on two channels at
different frequencies, L1=1575.42 MHz and L2=1227.6 MHz. The L2
channel broadcasts a signal used for military purposes (P code) and
occupies a 20 MHz band. The L1 channel emits a signal for civil
applications (C/A code) that occupies a 2 MHz band.
[0016] Therefore, multimedia receivers only use this L1 channel.
The reception level of the GPS signal for this channel is about
-130 dBm, which is 19 dB below the thermal noise (about -111 dBm on
a 2 MHz band).
[0017] After correlating the GPS signal with the spreading sequence
(despreading), the GPS signal occupies a 50 Hz band with a 43 dB
gain. Since the correlation operation is made within the digital
range, the analog-digital conversion is not a very sensitive point.
In general, a single 1-bit ADC is used in order to eliminate the
need for a controlled gain amplifier (CGA).
[0018] The overriding problem is the noise level added in the band
after quantification of the signal. If a single 1-bit quantifier is
used, the range of its input signal must be sufficiently low so
that the quantification noise is not too high. This aspect requires
appropriate filtering of disturbing sources and/or oversampling of
the very low level signal, and a high gain (about 100 dB) so that
the ADC can process the GPS signal level.
[0019] The following documents describe examples of GPS receivers:
[0020] Anna M. Murphy, Shinichi Tsutsumi, Peter Gaussen, "A Low
Power, Low-Cost Bipolar GPS Receiver Chip", IEEE Journal of
Solid-State Circuits, vol. 32, No. 4, April 1997, pp. 587-591;
[0021] Arvin R. Shahani, Derek K., Shaeffer, Thomas H. Lee, "A
12-mW Wide Dynamic Range CMOS Front-End for a Portable GPS
Receiver", IEEE Journal of Solid State Circuits, vol. 32, No. 12,
December 1997, pp. 2061-2070; [0022] Francesco Piazza, Qiuting,
Huang, A 1.75-GHz RF Front-End for Triple Conversion GPS Receiver",
IEEE Journal of Solid-State Circuits, vol. 33, No. 2, February
1998, pp. 202-209; [0023] D. Shaeffer, A. Shahani, S. Mohan, H.
Samavati, H. Rategh, M. Hershenson, M. Xu, C. Yue, D. Eddleman, T.
Lee, "A 115 mW CMOS GPS Receiver", Proceedings of ISSCC'98, Session
8, February 1998, pp. 122-123.
[0024] At the present time in known multimedia reicevers, each
proposed service (DAB and GPS) has its own radio frequency
reception system. Therefore two radio frequency reception systems
are simply placed side by side in the same casing, possibly sharing
a common power supply. Obviously, this means increased complexity
and consumption.
[0025] In particular, the purpose of the invention is to overcome
this disadvantage in prior art.
[0026] More precisely, one purpose of the invention is to provide a
dual mode reception device enabling reception firstly of
multi-carrier broadcast signals (for example DAB) and secondly
radio positioning signals (for example GPS) under optimum
conditions, particularly for consumption, size and complexity of
the means used.
[0027] Thus, one particular purpose of the invention is to provide
this type of device that has a sufficiently low consumption so that
it can be implemented in the form of a portable multimedia
receiver.
[0028] Obviously, another purpose of the invention is to provide
such a reception device at a low cost price compared with known
receivers, as a result of its lower technical complexity.
[0029] Another purpose of the invention is to provide this type of
reception device with good reception qualities despite the
cohabitation of two radio frequency systems.
[0030] These purposes, and others that will become clear later, are
achieved using a dual mode radio frequency reception device of the
type enabling reception firstly of multi-carrier broadcast signals
in a first frequency band, and secondly radio positioning signals
in a second frequency band.
[0031] According to the invention, this device comprises a single
preprocessing module, particularly including a pass-band antenna
filter in which the pass-band includes at least the said first and
second frequency bands, and outputting firstly to a first
processing system for the said multi-carrier broadcast signals, and
secondly to a second system for processing the said radio
positioning signals.
[0032] Therefore, the invention is based on sharing some resources
(preprocessing) which obviously leads to a reduction in the cost,
size and complexity, and electricity consumption. Therefore, this
enables high integration of the receiver on silicon.
[0033] Therefore, the invention proposes an innovative radio
frequency architecture that can include the reception of DAB and
GPS signals, for example about 1.5 GHz, advantageously up to the
generation of the I and Q digital channels.
[0034] Thus, the said single preprocessing module also
advantageously comprises at least one of the elements belonging to
the group comprising: [0035] a first low noise amplifier; [0036] a
first transposition stage to a first intermediate frequency, by
multiplying by a first transposition frequency; [0037] a second
amplifier.
[0038] In other words, the invention offers a major saving by
offering resource sharing (particularly the first transposition
stage).
[0039] Still with the objective of reducing the complexity, the
invention proposes optimized implementation of the different
frequencies used.
[0040] Thus, preferably a single analog-digital conversion
frequency is implemented to control the first digitization means in
the first processing system, and the second digitization means in
the second reception system.
[0041] For example, the said first digitization means may include a
delta-sigma pass-band modulator. The second digitization means may
comprise a "1-bit" quantifier.
[0042] Preferably, the reception device according to the invention
also comprises a frequency synthesizer outputting to the said first
and second processing systems, capable of generating at least two
of the frequencies belonging to the group comprising: [0043] the
said first transposition frequency; [0044] the said analog-digital
conversion frequency, [0045] a second transposition frequency
(first system) used by a second transposition stage to a second
intermediate frequency included in the said first processing
system; [0046] a second transposition frequency (second system)
used by a second transposition stage to a second intermediate
frequency included in the said second processing system.
[0047] As described in the preamble, and without being restrictive,
the said first processing system can advantageously be used for the
reception of DAB signals and the said second processing system for
the reception of GPS signals.
[0048] For example, the said first frequency band may be between
about 1452.192 MHz and 1491.392 MHz, and the said second frequency
band may be between about 1574.42 MHz and 1576.42 MHz.
[0049] The reception device according to the invention can be used
for applications in many domains. For example, it can be put into a
"car radio/radio navigation" unit for a car. Due to its low
consumption, it can also-very advantageously be used in portable
multimedia receivers. One advantageous application for this type of
device could be cooperation between broadcasting of geographic maps
by the DAB system and precise positioning on these maps by the GPS
system.
[0050] Other characteristics and advantages of the invention will
become clearer after reading the following description of a
particular embodiment of the invention given simply as illustrative
and non-restrictive examples, and the attached figures in
which:
[0051] FIG. 1 shows the frequency of the DAB and GPS channels used
by a dual mode receiver according to the invention;
[0052] FIG. 2 is a block diagram showing an embodiment of a
receiver according to the invention designed to receive and process
the signals in FIG. 1;
[0053] FIG. 3 shows a block diagram illustrating an advantageous
technique for synthesizing frequencies for the receiver in FIG.
2.
[0054] As described above, the proposed radio frequency
architecture according to the invention takes account of the
proximity of reception frequencies of the DAB and GPS signals to
optimize the receiver. FIG. 1 illustrates the frequency
distribution of these signals.
[0055] The DAB signals (L band) are organized into 23 channels and
are distributed on a 39.2 MHz band 11 between 1452.192 MHz and
1491.392 MHz.
[0056] The GPS system is based on two channels: [0057] a GPS1
channel 12 covering a 20 MHz band between 1217.6 MHz and 1237.6
MHz, corresponding to the P code; [0058] a GPS2 channel 13, with a
2 MHz frequency band between 1574.42 MHz and 1576.42 MHz. This is
the L1 channel corresponding to the C/A code.
[0059] The receiver according to the invention only processes the
L1 channel 13, for GPS aspects. Consequently, the receiver
according to the invention must cover at least the frequency band
14 with a band width of 124.228 MHz extending from 1452.192 MHz to
1576.42 MHz, so as to encompass the 23 DAB channels and the GPS2
channel (L1).
[0060] Unlike known systems, the DAB/GPS dual mode architecture
according to the invention can reduce the complexity and
consumption of the radio frequency receiver by sharing hardware
resources, as can be seen clearly in FIG. 2.
[0061] The receiver can be broken down into three main modules:
[0062] a pre-processing or "input" module 21 of the radio frequency
receiver which is common to the DAB and GPS channels; [0063] a
specific DAB processing module 22; [0064] a specific GPS processing
module 23.
[0065] Note that although these two processing modules 22 and 23
are independent, they preferably use the same frequencies, or
frequencies output from the same frequencies synthesizer, as will
become clearer in the following.
[0066] Therefore the input 21 of the radio frequency receiver is
common to the DAB and GPS channels. In particular it comprises:
[0067] an antenna filter 211; [0068] a low noise amplifier (LNA),
which is easier to manufacture than known systems that require
narrower bands due to the low quality factor (wide band); [0069] a
first intermediate frequency transposition stage 213 controlled by
a frequency F.sub.OL1=1179.648 MHz; [0070] a gain stage 214.
[0071] The two channels are processed independently to enable
simultaneous reception of the DAB and GPS signals. In other words,
the signal 215 output by the gain stage 214 is input into
processing modules 22 and 23 simultaneously.
[0072] For the DAB channel, the processing module 22 comprises
means of transposition to a second intermediate frequency
comprising a filter 221, an amplifier 222 and a mixer 223. The
frequency F.sub.OL3 controlling the filter 221 and the mixer 222 is
between 232, 352 and 270.016 MHz depending on which DAB channel is
selected. The signal obtained at the output is centered on 40.96
MHz. It is input to a filter 224 and then a controlled gain
amplifier (CGA) 225. A .DELTA..SIGMA. pass-band modulator 226
sub-samples the signal before digitizing it and then generating the
digital I and Q channels. I/Q demodulation and digital filtering
means 227 output data 228 on the I and Q channels.
[0073] The GPS processing module 23 comprises a filter 231 centered
on 395.772 MHz followed by a 20 dB amplifier 232 and a second
intermediate frequency transposition stage 233 controlled by
frequency F.sub.OL2=393.216 MHz. An LPF filter 234 and then a 40 dB
amplifier 235 is input into a 1-bit quantifier 236 that eliminates
the need for a controlled gain amplifier. A digital decorrelation
and filter module 237 outputs the GPS signals 229 onto the I and Q
channels.
[0074] The structure of this dual mode receiver also has the
advantage that it can share the same frequency synthesizer
illustrated in FIG. 3. With this technique, the number of
frequencies to be generated is reduced by two thirds.
[0075] The following frequencies are obtained starting from a
reference frequency F.sub.REF=32.768 MHz: [0076]
F.sub.ADC=F.sub.REF=32.768 MHz, which is input firstly to the
.DELTA..SIGMA. modulator 226 in the DAB processing module, and
secondly to the 1-bit quantifier 236 of the GPS processing module;
[0077] the frequency F.sub.OL1=36.F.sub.REF=1 179.648 MHz,
controlling the first transposition stage 213; [0078] the frequency
F.sub.OL2=12.F.sub.REF=393.216 MHz, controlling the second
transposition stage 233 of the GPS processing module; [0079] the
frequency F.sub.OL3=(107.n +14 522).F.sub.REF/2 048=232.352 . . .
270.016 MHz, controlling the second transposition stage 223 of the
DAB processing module (where n varies from 0 to 22 depending on
which DAB channel is selected).
[0080] These various frequencies can be obtained because the
frequency synthesis module comprises a transposition multiplier 31
that outputs into a voltage controlled oscillator (VCO) 32, and is
controlled by a frequency divider by 36 (33). The signal output
from oscillator 32 provides the frequency F.sub.OL1 and outputs it
into the divider by 36 (33). The frequency F.sub.OL1 is also
divided by 3 (divider 34) to obtain the frequency F.sub.OL2.
Furthermore, frequency F.sub.REF is output into a divider by 2048
(=2.sup.11) module 35 that outputs into a transposition multiplier
36 that outputs the frequency F.sub.OL3 through a voltage
controlled oscillator (VCO) (37). This frequency is looped back
onto a P/P+1 module (38) (corresponding to selection of the DAB
channel that is simultaneously input to a divider by 14 522 (39)
and a divider by 107 (310) that control the transposition
multiplier 36).
[0081] Thus the invention proposes a radio frequency architecture
optimized for the reception of DAB and GPS signals. In particular,
it enables the manufacture of portable multimedia receivers and,
for example, can be used in applications providing assistance for
individual navigation, to show a person his position (GPS) on a
downloaded map (DAB).
[0082] The reduction in cost and consumption of this type of
terminal makes it possible to consider large scale integration of
the receiver on silicon. Dual mode reception is optimized due to
sharing of hardware and frequency resources, largely because the
reception frequencies of the GPS and DAB channels (in the L band)
are close together.
* * * * *