DD300141A5 - DEVICE FOR RECEIVING RADIO SIGNALS - Google Patents

Abstract

The reception apparatus according to the invention comprises a receiving antenna (1), a fixed-gain preamplifying element (2), an amplifying element (8) having a series of output lines (13) with fixed amplification levels connected to a common conversion element (20) by way of a sampling element (17), the conversion element (20) being associated with a storage element (21) and with a stored signals selection means (22) for transmitting to a digital processing unit (23) those of the stored signals having the amplification level best matched to the digital processing unit (23). <IMAGE>

Description

For this 1 page drawings

This invention relates to an apparatus for receiving radio signals, and more particularly, though not exclusively, to a receiving apparatus for a station of a radio telephone network.

There are radio communication devices, in particular time division multiplexed radio communication devices, known in which the signals to be transmitted are organized in the form of packets which are transmitted successively on a radio channel. The receiving devices of such signals generally have a receiving antenna, a variable gain preamplifier connected to the receiving antenna, a filter element connected to the preamplifier, a variable gain amplifier, df s, connected to the output of the filter element An analog-to-digital conversion device having an input connected to the amplifying device and an output connected to a sensing element of the converted signals and to a digital processing unit, the sensing element of the converted signals in turn having a gain control device with an output connected to the Vorverstärkungsorgan and is connected to the reinforcing member is connected. The gain control means is adapted to match the gain of the preamplification and amplification means to the power of the received signal. Thus, if the received signal has been insufficiently amplified, the energy of the converted signal will not suffice for appropriate processing by the digital processing unit, whereas if the received signal has been over-amplified, it will be limited by the translator, which will no longer be its role can fulfill. In order for the gain control chain to function properly, there must be a sufficient number of bits in the transmission to allow measurement of the received level and automatic gain correction. Thus, when significant bits reach the gain chain, the gain is appropriately matched to the power of the signal and proper processing of that signal is ensured by the digital processing unit. Although the response times of the automatic gain control chains are very short, these timing chains are not adapted to receiving signals which do not have a sufficient number of bits that can be lost during the measurement and automatic gain control process. In this case, there is a risk that the gain is very badly adapted and that data is lost.

An object of this invention is to propose a device for receiving radio signals adapted to the processing of signals in which sufficient time is not available for gain correction. To achieve this aim, according to the invention, a device with a receiving antenna, a Vorverstärkungs- and filter member, which is connected to the receiving antenna, a gain element, which is connected to the output of the Vorverstärkungs- and filter member, an analog-to-digital conversion member, with the Output of the amplifying member is connected, and a digital processing unit, which is connected to the conversion member, is provided, in which the amplifying member has parallel-connected gain elements with fixed gain and in which the device between the conversion member and the digital processing unit means for storing signals with different Gain levels, means for connecting these signals, selecting a gain level adapted to the digital processing unit, and transmitting the signals stored at that gain level.

Thus, a received signal is stored simultaneously with different gain levels, so that the reading of the Memory, selecting one of the stored signals corresponding to the most suitable gain level, and

the transmission of this signal to the digital processing unit after reception, if a relatively large processing time is available. It should also be noted that the most appropriate signal

Gain level is selected for each received packet. The device according to the invention thus ensures a Transmission of each received packet at a significantly constant level to the digital processing unit, even if

the power level of the received signal at the receiving antenna varies with time, while automatic gain control devices can adapt only gradually to such changes.

According to an advantageous variant of the invention, the receiving device has one for a plurality of reinforcing elements

common transfer member, said common transfer member is connected to the associated reinforcing elements via a controlled connecting member, so that cyclically a connection between a reinforcing element and the common transfer member can be produced.

Thus, one and the same translator will sample the received signal at different ones Ensures gain levels. According to a preferred embodiment of the invention, the reinforcing member has a plurality of series connected Reinforcement stages, wherein in each stage reinforcing elements connected in parallel according to a general pyramid structure Thus, when limiting the gain of each stage, a high pre-reinforcement quality results. Other features and advantages of the invention will become apparent upon reading the following description of a particular

not limiting embodiment of the invention in conjunction with the accompanying drawings, in which

Fig. 1 is a block diagram of one embodiment of the apparatus of the invention; Fig. 2 is a more detailed block diagram of a portion of the apparatus of Fig. 1;

With reference to the figures, the apparatus according to the invention for receiving radio signals has a Receiving antenna 1, which is connected to a Vorverstärkungs- and filter element 2. Thus, as can be seen on Fipur 2, the preamplification and filter element has a preamplification element with fixed gain 3,

whose output is connected to a bandpass filter 4.

The output of the bandpass filter 4 is connected to an input of a mixer 5, from which another input with a Local oscillator 6 is connected. A centered on the frequency of the local oscillator 6 filter 7, whose bandwidth is the same

is the signal to be processed, is connected to the output of the mixer 5.

The output of Vorverstärkungs- and filter element 2 is connected to a reinforcing member 8, the (see Figure 2) a

first gain stage with two parallel amplifiers with fixed gain has. In the illustrated

Embodiment, one of the amplifiers 9 has a gain g corresponding to the strongest signal received by the system

is adapted while the other amplifier 9 has a gain g plus 4OdB. Behind the amplifiers *? follow mixer 10 with a first input connected to one of the amplifiers 9 and a second input, the mi ', a

Local oscillator 11 is connected, whose function is to vorzunehmer a frequency conversion, the signal on

center the frequency Fb / 2, where Fb is the bit frequency of the signal. Behind the mixers 10 is followed by a filter element 12 for

Elimination of the leftovers. The output of each mixer 12 is connected in parallel with 4 output lines 13. At every group of Output lines 13 has one of the lines no amplifier, a second line has an amplifier 14 with a 1OdB gain, a third line, an amplifier 15 with 2OdB gain, and a fourth line one Amplifier 16 with a gain of 3OdB, which represent a second gain stage of the reinforcing member 8. Have so

the output lines 13 gain levels, which are between 0 and 7OdB gain over the input signal of the

Reinforcing member 8 are staggered. The output lines 13 of the amplifying member 8 are connected to the input of a scanner 17, which is a series of

connected in parallel switching means 18 which are controlled by a control member 19 to cyclically establish a connection between a line 13 and a common analog-to-digital conversion device 20. In the described

Embodiment in which the conversion element is the same for all gain levels, the sampling frequency is 2 Fb

for each line 13. i. 16Fb for the scanner to achieve significant sampling of the received signals.

The output of the conversion device 20 is connected to an input of storage means 21, one of which Input is connected to the control member 19, to each scan obtained by the translation device 20 has an address in To be able to match the match with the memory 13 associated with the stored sample. The saliva center! 21

are connected to means for selecting stored signals 22 representing the total sample tone of a stored signal

Read packets for each gain level and a selection of the best matched gain level in dependence

of criteria entered in the selection means, such as mean energy level or number of

Limitations. Incidentally, the storage means 21 and the means for selecting stored sigrides 22 are digital Processing unit 23 is connected so that after the gain level has been determined, the packet received at the

is best adapted, the means for selecting stored signals, the information about this gain level to the digital

Transfer processing unit and at the same time the transmission of the entire with the gain level detected Scans of the storage means 21 to the digital processing unit 23 cause. It should be noted that for each packet, the selection of the gain level after storing the entire bits of a Package is done. The selection is thus made not only on the non-significant bits of a packet, but also on the

significant bits, so the choice is of very high quality.

Moreover, as the selection is made on every parcel received, it is specially adapted, even if the level of the

received signal is very different between the individual packets.

Of course, the invention is not limited to the described embodiment, and it can be Implementation changes are made without departing from the scope of the invention. In particular,

Although the invention has been described with a reinforcing member 8 having eight staggered output lines per 10 dB, the

Number of gain levels in each system adapted to the range of levels at which a signal is received

must become.

Although the receiving device according to the invention with a common conversion member, with a Abtastorgan

can also be provided to provide each gain level with a separate converter or to combine a plurality of converters, each associated with a plurality of amplification lines.

Although amplification of the entire Fb / 2 centered signal has been provided to the gain member 8, in the

are also provided to decompose the received signal via a phase shifter in the components I and Q, then doubles the number of gain elements of the second gain stage, while the sampling frequency is divided on each line 13 over the illustrated embodiment by two.

Claims (3)

A device for receiving radio signals having a receiving antenna (1), a Vorverstärkungs- and filter member (2) which is connected to the receiving antenna, a gain element (9) which is connected to the output of the Vorverstärkungs- and filter member, an analog Digital translation device (20) connected to the output of the amplifying member and a digital processing technique (23) connected to the translation element, characterized in that the amplifying member has solid gain amplification elements (9, 14, 15) connected in parallel , 16), and in that the device between the actuator (20) and the digital processing unit (23) has means for storing signals of different gain levels, means (22) for connecting these signals, for selecting one adapted to the digital processing unit Gain levels and to transmit the signals stored at that gain level. 2. Device forwards. Receiving the radio signals according to claim 1, characterized in that it comprises a transfer element (20) common to several reinforcing elements, said common transfer element having the associated reinforcing elements via a controlled start-up member (17) for cyclically establishing a connection between a support element and the common transfer member (17). 20) is connected. 3. Vorrittitung for receiving radio signals according to claim 1 or claim 2, characterized in that the reinforcing member (8) in series a plurality of gain stages, wherein in each stage reinforcing elements (9; 13,14,15) are connected in parallel according to a general pyramid structure ,