Systems and methods for communicating using ask or qam with uneven symbol constellation

Abstract

Systems and methods of performing ASK or QAM modulation with uneven distance between symbols are provided. These are used to provide differing BER performances among bits sent from a transmitter to a receiver.

1 . A transmitter comprising:
 a UASK (amplitude shift keying with uneven distance) modulator or UQAM (quadrature amplitude modulation with uneven distance) modulator that generates symbols from input bits.   
     
     
         2 . The transmitter of  claim 1  further comprising:
 a parameter adaptor that determines a constellation to be used by the UASK modulator or the UQAM modulator. 
 
     
     
         3 . The transmitter of  claim 2  further comprising:
 the parameter adaptor determines the constellation to be used by the UASK modulator or the UQAM modulator by determining at least one parameter reflective of unevenness in the constellation used by the UASK modulator or the UQAM modulator. 
 
     
     
         4 . The transmitter of  claim 2  wherein the parameter adaptor is configured to determine the constellation taking into account at least one adaptation input. 
     
     
         5 . The transmitter of  claim 4  wherein the at least one adaptation input comprises at least one of: required SNR (signal to noise ratio) or SINR (signal-to-interference plus noise ratio) for a targeted service quality, measured SNR or SINR, RSSI (received signal strength indication), BER, BLER (block error rate), Mean BEP (bit error rate probability), CV BEP (coefficient of variance for BEP), FER (frame error rate), advanced receiver Capabilities (for example DARP Phase I, DARP Phase II), MCS (modulation and coding scheme). 
     
     
         6 . The transmitter of  claim 2  wherein:
 the parameter adaptor is configured to determine the constellation by taking into account a target BER performance for different bit positions of the input bits. 
 
     
     
         7 . The transmitter of  claim 2  wherein:
 the parameter adaptor is configured to determine the constellation by taking into account a target differentiated BER performance for different bit positions of the input bits that are for receipt by a common receiver. 
 
     
     
         8 . The transmitter of  claim 2  further comprising:
 a bit stream mapper that determines how bits will be mapped to symbols. 
 
     
     
         9 . The transmitter of  claim 1  further configured to transmit an indication of the constellation used by the UASK modulator or the UQAM modulator. 
     
     
         10 . The transmitter of  claim 9  wherein the transmitter is configured to transmit the indication of the constellation by at least one of:
 transmitting a training sequence within which is embedded the indication; 
 transmitting an initial indication of the constellation; 
 transmitting the indication as signalling on an ongoing basis. 
 
     
     
         11 . The transmitter of  claim 1  further comprising:
 a codec that processes a first set of bits to produce bits of a codec output; 
 a bit stream mapper that sequences bits of the codec output to produce the input bits to the UASK modulator or UQAM modulator such that at of higher importance is mapped to a strong bit position in the uneven constellation. 
 
     
     
         12 . The transmitter of  claim 1  wherein:
 a codec that processes a first set of bits to produce bits of a codec output; 
 a bit stream mapper that sequences bits of the codec output to produce the input bits to the UASK modulator or UQAM modulator the sequencing performed by the bit stream mapper sequences the bits of the codec output such that at least one bit that is of less importance is mapped to a weak bit position in the uneven constellation. 
 
     
     
         13 . The transmitter of  claim 11  wherein the sequencing performed by the bit stream mapper sequences the bits of the codec output such that at least one bit that is least important is mapped to a weak bit position in the uneven constellation. 
     
     
         14 . The transmitter of  claim 11  further configured to adapting the constellation unevenness dynamically in response to changing channel conditions to preserve voice quality. 
     
     
         15 . The transmitter of  claim 11  further comprising:
 a bit puncturer that punctures bits to reduce the overall transmitted bit stream. 
 
     
     
         16 . The transmitter of  claim 11  further configured to adapt the value and degree of variance of the constellation unevenness in line with changes in a mode of the codec. 
     
     
         17 . The transmitter of  claim 11  wherein the bits of the codec output are classified into a plurality of classes, and wherein the sequencer maps relatively more important class(es) to stronger bit positions and maps relatively less important class(es) to weaker bit positions. 
     
     
         18 . A method comprising: generating UASK (amplitude shift keying with uneven distance) symbols or UQAM (quadrature amplitude modulation with uneven distance) symbols from input bits; transmitting a signal containing the symbols. 
     
     
         19 . The method of  claim 18  further comprising: determining a constellation to be used when performing UASK modulation or the UQAM modulation. 
     
     
         20 . The method of  claim 19  wherein: determining the constellation to be used when performing UASK modulation or UQAM modulation comprises determining at least one parameter reflective of unevenness in the constellation. 
     
     
         21 . The method of  claim 19  wherein determining a constellation comprises taking into account at least one adaptation input. 
     
     
         22 . The method of  claim 19  wherein: determining a constellation comprises taking into account a target BER performance for different bit positions of the input bits. 
     
     
         23 . The method of  claim 19  wherein: determining a constellation comprises taking into account a target differentiated BER performance for different bit positions of the input bits that are for receipt by a common receiver. 
     
     
         24 . The method of  claim 19  further comprising: performing sequencing on bits that determines which bits are mapped to which bit positions for bit-to-symbol mapping. 
     
     
         25 . The method of  claim 24  further comprising: transmitting an indication which bits are mapped to which bit positions for bit-to-symbol mapping. 
     
     
         26 . The method of  claim 18  further comprising: transmitting an indication of the constellation used in performing UASK modulation or UQAM modulation. 
     
     
         27 . The method of  claim 18  further comprising: performing a codec operation on a first set of bits to produce bits of a codec output; sequencing bits of the codec output to produce the input bits to the UASK modulator or UQAM modulator such that at least one bit that is of higher importance is mapped to a strong bit position in the uneven constellation. 
     
     
         28 . The method of  claim 27  wherein: the sequencing sequences the bits of the codec output such that at least one bit that is less important is mapped to a weak bit position in the uneven constellation. 
     
     
         29 . The method of  claim 27  further comprising: adapting the constellation unevenness dynamically in response to changing channel conditions to preserve voice quality. 
     
     
         30 . The method of  claim 27  further comprising: classifying the bits of the codec output are classified into a plurality of classes; wherein the sequencing maps relatively more important class(s) to stronger bit positions and maps relatively less important class(s) to weaker bit positions. 
     
     
         31 . A receiver comprising: a UASK (amplitude shift keying with uneven distance) demodulator or UQAM (quadrature amplitude modulation with uneven distance) demodulator that produces bits from received symbols. 
     
     
         32 . The receiver of  claim 31  wherein all of the bits produced from the received symbols are for the receiver. 
     
     
         33 . The receiver of  claim 31  further comprising: a parameter adaptor that determines a constellation to be used by the UASK demodulator or the UQAM demodulator. 
     
     
         34 . The receiver of  claim 31  further configured to extract at least one parameter reflective of unevenness in the constellation from the signal or elsewhere. 
     
     
         35 . The receiver of  claim 31  further configured to extract an indication of which bits were mapped to which bit positions when bit-to-symbol mapping was performed. 
     
     
         36 . The receiver of  claim 31  further comprising a bit stream demapper, wherein the bits are received using a UQAM or UASK constellation that sequences through a predetermined set of different constellation unevennesses, and wherein the bit stream mapper undoes a mapping of the bits of a block of bits to a respective position in constellations having the predetermined set of different constellations unevennesses. 
     
     
         37 . The receiver of  claim 36  further configured to receive an indication of an update in the predetermined set of different constellation unevennesses. 
     
     
         38 . A method comprising: receiving a signal containing symbols; performing UASK (uneven amplitude shift keying) demodulation or performing UQAM (uneven quadrature amplitude modulation) demodulation to produce bits from the symbols. 
     
     
         39 . The method of  claim 38  further comprising: determining a constellation to be used in performing UASK demodulation or UQAM demodulation. 
     
     
         40 . The method of  claim 39  wherein determining a constellation to be used in performing UASK demodulation or UQAM demodulation comprises extracting at least one parameter reflective of unevenness in the constellation from the signal or elsewhere. 
     
     
         41 . The method of  claim 38  further comprising: performing bit de-mapping to reverse a bit stream mapping operation that mapped bits to bit positions for modulation. 
     
     
         42 . The method of  claim 18  wherein the UASK symbols or UQAM symbols are UASK symbols. 
     
     
         43 . The method of  claim 18  wherein the UASK symbols or UQAM symbols are UQAM symbols. 
     
     
         44 . The receiver of  claim 31  wherein the UASK demodulator or UQAM demodulator is a UASK demodulator. 
     
     
         45 . The receiver of  claim 31  wherein the UASK demodulator or UQAM demodulator is a UQAM demodulator.