Method and system for radio transmission of digital signals
AssigneeSiemens Aktiengesellschaft
InventorsPaul-Walter Baier, Markus Nasshan, Bernd Steiner
Life of this patent
Estimating the term…
Abstract
In a radio system which operates using code division multiplex (CDMA) the interference in the training sequences, for example interblock sequences, of all the K subscribers in the received signal is overcome before data detection at the receiving end. The interference in the training sequences of all K subscribers is modeled using the estimated channel pulse responses and, finally, is subtracted from the received signal. The method and apparatus can be used in CDMA mobile radio systems, in particular with joint detection.
Claims20
A method for simultaneously transmitting digital signals from a transmitting end to a receiving end, via channels which are different at the receiving end before detection of the digital signals, comprising the steps of:
- estimating pulse responses of received digital signals;
- transmitting each of the digital signals at discrete times in the form of successive bursts, each burst is composed of a specific training sequence for channel estimation at the receiving end and of at least one of data block which is transmitted after the training sequence, said one data block having the digital signals in the form of data symbols;
- assigning a spread code to the bursts, the spread code being applied linearly in order to achieve a code division multiple access mode;
- for overcoming interference in the training sequence with the data blocks at the receiving end before the actual signal detection, modeling said interference using the estimated pulse response per channel and subtracting the modeled interference from the received signal.
A method for simultaneously transmitting digital signals from a transmitting location to a receiving location, via channels, which are different at the receiving end, before detection of the digital signals, comprising the steps of:
- estimating pulse responses of received digital signals;
- transmitting each of the digital signals at discrete times in the form of successive bursts, each burst being composed of a specific training sequence for channel estimation at the receiving end and of at least one of data block which is transmitted after the training sequence, said one data block having the digital signals in the form of data symbols;
- assigning a spread code to the bursts, the spread code being applied linearly in order to achieve a code division multiple access mode;
- for overcoming interference in the training sequence with the data blocks at the receiving end before the actual signal detection, modeling said interference using the estimated pulse response per channel and subtracting the modeled interference from the received signal;
- providing a radio system of cellular construction having a plurality of subscribers and having one base station per radio cell, transmission of the signals in a radio cell being carried out using a JD-CDMA method;
- handling in parallel a multiplicity of wanted connections in a common RF frequency band, each of wanted signals being spread by a specific factor on the frequency axis at the transmitting location using a different spread code;
- decoding the spread wanted signals at the receiving location using said spread code;
- and
- using a JD-CDMA specific signal detection unit for signal detection in the receiving devices.
A system for radio transmission of digital signals from a transmitting end to a receiving end, via channels which are different at the receiving end before detection of the digital signals, comprising:
- each of the digital signals being transmitted at discrete times in the form of successive bursts, each burst is composed of a specific training sequence for channel estimation at the receiving end and of at least one of data block which is transmitted after the training sequence, said one data block having the digital signals in the form of data symbols;
- a spread code assigned to the bursts, the spread code being applied linearly in order to achieve a code division multiple access mode;
- for overcoming interference in the training sequence with the data blocks at the receiving end before the actual signal detection, said interference is modeled using an estimated pulse response per channel and subtracting the modeled interference from the received signal;
- a digital signal processor at the receiving end to overcome any interference in the training sequence before actual signal detection;
- and
- said interference being modeled using the estimated pulse response per channel and the modeled interference is subtracted from the received signal.
A method for simultaneously transmitting digital signals from a transmitting location to a receiving location, via channels, which are different at the receiving end, before detection of the digital signals, comprising the steps of:
- estimating pulse responses of received digital signals;
- transmitting each of the digital signals at discrete times in the form of successive bursts, each burst being composed of a specific training sequence for channel estimation at the receiving end and of at least one of data block which is transmitted after the training sequence, said one data block having the digital signals in the form of data symbols;
- assigning a spread code to the bursts, the spread code being applied linearly in order to achieve a code division multiple access mode;
- for overcoming interference in the training sequence with the data blocks at the receiving end before the actual signal detection, modeling said interference using the estimated pulse response per channel and subtracting the modeled interference from the received signal;
- providing a radio system of cellular construction having a plurality of subscribers and having one base station per radio cell, transmission of the signals in a radio cell being carried out using a JD-CDMA method;
- handling in parallel a multiplicity of wanted connections in a common RF frequency band, each of wanted signals being spread by a specific factor on the frequency axis at the transmitting location using a different spread code;
- decoding the spread wanted signals at the receiving location using said spread code;
- using a JD-CDMA specific signal detection unit for signal detection in the receiving devices;
- providing a linear data block equalizer with a downstream quantization stage for data detection, continuous-value estimated values of the data symbols being determined in the block equalizer and being combined to form vectors;
- and
- obtaining discrete-value estimated values of the data symbols in the quantization stage by quantization of the continuous value estimated values.
Dependencies are inferred from the claim text.