Method and device for calculating bit error rate of received signal
AssigneeTelefonaktiebolaget L M Ericsson (publ)
InventorDignus-Jan Moelker
Life of this patent
Estimating the term…
Abstract
System and method of estimating radio channel bit error rate (BER) in a digital radio telecommunications system wherein the soft output of the turbo decoder is used as pointer or index to look-up-tables containing the bit-wise BER of a certain bit in the data field of the received frame. A quantizer quantizes the received data frame and the quantized bit operates on a switch which selects the appropriate look-up-table. By means of accumulation and scaling the average BER of a certain amount of bits are calculated. Decoding bit-errors may occur but as they are submitted to posterior probability estimation, systematic errors which normally happen at low SNR are avoided.
Claims18
A system for determining a bit error rate in a digital communication system, comprising:
- a transmitting station;
- a receiving station having a decoder;
- the transmitting station arranged for transmitting a bit sequence to a receiving station;
- the receiving station arranged for receiving the bit sequence;
- the decoder arranged for decoding one or more bits out of the received bit sequence;
- a plurality of look-up tables arranged for containing predetermined bit error rates related to ranges of soft output values;
- a quantizer being arranged for quantizing the received bit;
- a switch being arranged for selecting an output, representing a Bit error Rate contribution, of one of the look up tables out of the plurality of look up tables, the selection being based on the quantized bit;
- a soft-output of the decoder being arranged as an index to the plurality of look up tables for retrieving a bit-wise bit error rate contribution to the bit error rate of a received bit sequence;
- and
- a summing and scaling device being arranged for accumulating and averaging the bit-wise BER.
A receiving station system arranged for determining a bit error rate in transmitted bit sequence, comprising:
- a decoder arranged for decoding one or more bits out of the received bit sequence;
- a plurality of look-up tables arranged for containing predetermined bit error rates related to ranges of soft output values;
- a quantizer being arranged for quantizing the received bit;
- a switch being arranged for selecting an output representing a Bit Error Rate contribution, of one of the plurality of look up tables, the selection being based on the quantized bit;
- a soft-output of the decoder being arranged as an index to the plurality of look up tables for retrieving a bit-wise bit error rate contribution to the bit error rate of a received bit sequence;
- a summing and scaling device being arranged for accumulating and averaging the bit-wise BER.
A method for determining a bit error rate in a digital communication system comprising a transmitting station and a receiving station having a decoder comprising the steps of:
- transmitting a bit sequence to the receiving station by the transmitting station;
- receiving the bit sequence by the receiving station;
- decoding a bit out of the received bit sequence by the decoder;
- quantizing the received bit by a quantizer;
- selecting an output of a look up table, the look up table being one of a plurality of look up tables, the selection being based on the quantized bit;
- indexing the selected look up table, for obtaining a bit-wise bit error rate of the received bit sequence, by the soft-output of the decoder;
- accumulating and averaging the bit-wise BER of the received bit sequence by a summing and scaling device, resulting in the estimated average BER.
Dependencies are inferred from the claim text.