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EP-4020858-B1 - BLUETOOTH RECEIVER, ELECTRONIC DEVICE AND METHOD FOR A BLUETOOTH RECEIVER

EP4020858B1EP 4020858 B1EP4020858 B1EP 4020858B1EP-4020858-B1

Inventors

  • FRIEDMAN, AVISHAY
  • REGEV, YARDEN
  • LEE, JINYONG
  • GUREVITZ, ASSAF

Dates

Publication Date
20260506
Application Date
20201223

Claims (15)

  1. A Bluetooth receiver (30), comprising: interface circuitry (36) configured to receive a receive packet; physical layer processing circuitry (34) configured to: demodulate the receive packet into a bit stream representing a sequence of data symbols; determine a number of bits in the bit stream having a highest likelihood of being erroneous as weak-bits; and determine locations of the identified weak-bits in the bit stream; medium access control layer processing circuitry (32) configured to: receive the bit stream and information about the determined locations of the identified weak-bits from the physical layer processing circuitry (34): flip one of the weak-bits and a sequential bit in the bit stream in order to generate a modified bit stream, the sequential bit immediately follows the flipped weak-bit in the bit stream; run a respective cyclic redundancy check on the bit stream and the modified bit stream; and compare results of the cyclic redundancy checks on the bit stream and on the modified bit stream.
  2. The Bluetooth receiver (30) according to claim 1, wherein the physical layer processing circuitry (34) is configured to: demodulate the receive packet by soft decision demodulation into the bit stream, determine soft information indicating the respective likelihood of being erroneous for the bits in the bit stream, and identify the number of weak-bits based on the soft information.
  3. The Bluetooth receiver (30) according to any of the preceding claims, wherein the physical layer processing circuitry (34) is further configured to sort the weak-bits in the bit stream in an order of the likelihood of being erroneous; and wherein the medium access control layer processing circuitry (32) is further configured to flip one of the weak-bits and the sequential bit in the bit stream based on the order of the likelihood of being erroneous.
  4. The Bluetooth receiver (30) according to claim 1, wherein the interface circuitry (36) is further configured to receive a retransmission packet; and the physical layer processing circuitry (34) is further configured to: demodulate the retransmission packet into a second bit stream; apply a bitwise exclusive or operation on the bit stream and the second bit stream in order to generate a third bit stream; and determine the number of weak-bits based on the third bit stream.
  5. The Bluetooth receiver (30) according to any of the preceding claims, wherein each demodulated data symbol in the sequence of demodulated data symbols is represented by at least two bits in the bit stream; the one of the weak-bits belongs to a first demodulated data symbol in the sequence of demodulated data symbols; and the sequential bit belongs to a second demodulated data symbol in the sequence of demodulated data symbols that immediately follows the first demodulated data symbol in the sequence of demodulated data symbols.
  6. The Bluetooth receiver (30) according to claim 5, wherein the physical layer processing circuitry (34) is further configured to determine a bit among the bits belonging to the second demodulated data symbol with the highest likelihood for being erroneous based on a least significant bit and a most significant bit among the bits belonging to the second demodulated data symbol.
  7. The Bluetooth receiver (30) according to any one of claims 5 - 6, wherein the physical layer processing circuitry (34) is further configured to apply a bitwise exclusive or operation on bits belonging to the first demodulated data symbol to determine a bit with the highest likelihood of being erroneous in the sequential symbol.
  8. The Bluetooth receiver (30) according to any one of the preceding claims, wherein if the bit stream fails its cyclic redundancy check and the modified bit stream passes its cyclic redundancy check, the medium access control layer processing circuitry (32) is further configured to further process only the modified bit stream among the bit stream and the modified bit stream.
  9. The Bluetooth receiver (30) according to any one of claims 1 - 7, wherein if the bit stream and the modified bit stream fails its cyclic redundancy check, the medium access control layer processing circuitry (32) is further configured to perform the following iterative processing in i-th iterations with 1 < i, wherein i is a number of weak-bit permutations with one flip of a weak-bit at a time: flip one weak-bit and a sequential bit in a bit stream of the (i-1)-th iteration in order to generate a bit stream of the i-th iteration with an unused permutation of weak-bits, wherein the modified bit stream is used as the bit stream of the (i-1)-th iteration for the first iteration; run the cyclic redundancy check on the bit stream of the i-th iteration; and determine whether one of the following stop conditions is fulfilled: a) the bit stream of the i-th iteration passes the cyclic redundancy check or b) all permutations of weak-bit are used to generate a bit stream of the (i)-th iteration; and stop the iterative processing if one of the stop conditions is fulfilled.
  10. The Bluetooth receiver (30) according to claim 9, wherein the medium access control layer processing circuitry (32) is further configured to further process only the modified bit stream of the i-th iteration among the bit stream and the modified bit streams if stop condition a) is fulfilled.
  11. The Bluetooth receiver (30) according to claim 9, wherein the medium access control layer processing circuitry (32) is further configured to reject the bit stream if stop condition b) is fulfilled.
  12. The Bluetooth receiver (30) according to any one of claims 1 - 7, wherein if the bit stream and the modified bit stream pass the respective cyclic redundancy check, the medium access control layer processing circuitry (32) is further configured to reject the bit stream.
  13. The Bluetooth receiver (30) according to any one of claims 1 - 7, wherein if the bit stream passes its cyclic redundancy check and the modified bit stream fails its cyclic redundancy check, the medium access control layer processing circuitry (32) is further configured to perform the following iterative processing in i-th iterations with 1 < i, wherein i is a number of weak-bit permutation with one flip of a weak-bit at a time: flip one weak-bit and a sequential bit in a bit stream of the (i-1)-th iteration in order to generate a bit stream of the i-th iteration with an unused permutation of weak-bits, wherein the modified bit stream is used as the bit stream of the (i-1)-th iteration for the first iteration; run the cyclic redundancy check on the bit stream of the i-th iteration; and determine whether one of the following stop conditions is fulfilled: a) the bit stream of the i-th iteration passes the cyclic redundancy check or b) all permutations of weak-bit are used to generate a bit stream of the (i)-th iteration; and stop the iterative processing if one of the stop conditions is fulfilled.
  14. Electronic device (90) comprising a Bluetooth receiver (30) according to any one of the preceding claims.
  15. A method (200) for a Bluetooth receiver (30), comprising receiving (210) a receive packet by physical layer processing circuitry (34); demodulating (220), by the physical layer processing circuitry (34), the receive packet into a bit stream representing a sequence of data symbols; determining (230), by the physical layer processing circuitry (34), a number of bits in the bit stream having a highest likelihood of being erroneous as weak-bits; determining (240), by the physical layer processing circuitry (34), locations of the identified weak-bits in the bit stream; transmitting (250) the bit stream and information about the determined locations of the identified weak-bits from the physical layer processing circuitry (34) to a medium access layer processing circuitry (34); flipping (260), by the medium access layer processing circuitry (34), one of the weak-bits and a sequential bit in the bit stream in order to generate a modified bit stream, the sequential bit immediately follows the flipped weak-bit in the bit stream; running (270), by the medium access layer processing circuitry (34), a respective cyclic redundancy check on the bit stream and on the modified bit stream; and comparing (280), by the medium access layer processing circuitry (34), results of the cyclic redundancy checks on the bit stream and on the modified bit stream.

Description

Field The present disclosure relates to packet management for Bluetooth receivers. In particular, examples relate to Bluetooth receivers, an electronic device and methods for a Bluetooth receiver. Background Conceptual models for Bluetooth (BT) receiver implementation separate communication in the BT receiver into different layers such as physical layer (PHY), medium access control (MAC) etc. The PHY is responsible for proper decoding of the received bits while the MAC is responsible for link level management. This separation may lead to a decrease in performance at the BT receiver. However, separation of the PHY and the MAC may be desired because they may have different stacks and run on different system-on-chips (SOCs). Thus, a BT receiver with improved performance may be desired. US 2011 / 209 029 A1 discloses a method comprising passing a signal sequence to a bit error identification circuitry, that is operative to identify, by processing bits and/or symbols of a signal sequence, error locations therein. In accordance with performing error correction based on CRC, one approach involves performing bit flipping of the corresponding bits of the received signal sequence that are in the identified bit-error locations. The receiving communication device could successively flip one-bit at a time and correspondingly re-compute the remainder for each of the possible modified signal sequences. If the current bit position does contain the actual error, then the received signal sequence of stream will equal the original stream and the remainder will be zero. In such an instance, the bit-error location is then known, and the bit-error can be corrected. US 2015/236717 A1 discloses a method of decoding a signal comprising receiving a signal to be decoded, where the signal includes at least one symbol, decoding the signal in stages, where each at least one symbol of the signal is decoded into at least one bit per stage. A Log-Likelihood Ratio (LLR) and a path metric are determined for each possible path for each at least one bit at each stage. The method further comprises determining the magnitudes of the LLRs, identifying K bits of the signal with the smallest corresponding LLR magnitudes and identifying, for each of the K bits, L possible paths with the largest path metrics at each decoder stage for a user- definable number of decoder stages. Further, the method comprises performing forward and backward traces, for each of the L possible paths, to determine candidate codewords, performing a Cyclic Redundancy Check (CRC) on the candidate codewords and stopping after a first candidate codeword passes the CRC. Brief description of the Figures Some examples of apparatuses and/or methods will be described in the following by way of example only, and with reference to the accompanying figures, in which Fig. 1 shows a block schema of an example of a BT receiver;Fig. 2 shows a flow-chart of an example of a method for a BT receiver;Fig. 3 shows a flow-chart of another example of a method for a BT receiver;Fig. 4 shows a flow-chart of another example of a method for a BT receiver;Fig. 5 shows exemplary courses of a bit error rate as a function of a signal to noise ratio for different BT receivers;Fig. 6 shows different logic circuits for determining the sequential bit;Fig. 7 shows a logic circuit for performing a cyclic redundancy check based on lookup tables with syndromes;Fig. 8 shows a block diagram of circuitry for soft decoding; andFig. 9 shows a block diagram of an example of a wireless communication device. Detailed Description Various examples will now be described more fully with reference to the accompanying drawings in which some examples are illustrated. In the figures, the thicknesses of lines, layers and/or regions may be exaggerated for clarity. Accordingly, while further examples are capable of various modifications and alternative forms, some particular examples thereof are shown in the figures and will subsequently be described in detail. However, this detailed description does not limit further examples to the particular forms described. Further, examples may cover all modifications, equivalents, and alternatives falling within the scope of the disclosure. Like numbers refer to like or similar elements throughout the description of the figures, which may be implemented identically or in modified form when compared to one another while providing for the same or a similar functionality. It will be understood that when an element is referred to as being "connected" or "coupled" to another element, the elements may be directly connected or coupled or via one or more intervening elements. If two elements A and B are combined using an "or", this is to be understood to disclose all possible combinations, i.e. only A, only B as well as A and B. An alternative wording for the same combinations is "at least one of the group A and B". The same applies for combinations of more than 2 Elements. The terminology used herei