Interference Mitigation in HighSpeed Communications The Multipath Effect

1
Interference Mitigation in High-Speed
CommunicationsThe Multipath Effect
Real measurements obtained in an office
environment Transmitted signal BPSK at 2Msps
Recorded received signal (after demodulation)
Spectrum of the transmitted signal
2
Interference Mitigation in High-Speed
CommunicationsThe Multipath Effect
Real measurements obtained in an office
environment Transmitted signal BPSK at 10 Msps
Recorded received signal (after demodulation)
Notice the effect of the channel
Spectrum of the transmitted signal
3
Interference Mitigation in High-Speed
CommunicationsThe Multipath Effect
Real measurements obtained in an office
environment Transmitted signal BPSK at 25 Msps
Recorded received signal (after demodulation)
Spectrum of the transmitted signal
Spectrum of the rceived signal
4
Interference Mitigation in High-Speed
CommunicationsThe Multipath Effect
16-QAM 10 Msps
16-QAM 25 Msps
Spectrum of the transmitted signal
Recorded received signal
5
Conclusion

• To overcome the rate limitation imposed by the
  channel, wireless access techniques need to be
  closely integrated with interference mitigation
  techniques, such as
• Channel equalization
• Multicarrier transmission
• Smart antenna array