Her Majesty the Queen in Right of Canada as Represented by the Minister of Industry Through the Communications Research Centre Canada

Nortel Networks Corporation

Colin Brown

Philip Vigneron

Daniel Boudreau

Christian Dubuc

The invention relates to a method of non-coherent decoding an encoded CPM signal received by a wireless receiver, and a CPM decoder implementing the method, wherein the signal is generated by a transmitter using a serial concatenation of an outer encoder, an interleaver and an M-ary CPM modulator, and may have a frequency-hopping RF carrier. In a preferred embodiment, the method includes iteratively decoding the received signal by first recursively finding a sub-set of dominant sequences of CPM symbols that maximize a path metric for one hop interval using a non-coherent CPM detector, determining on the basis of this sub-set a sequence of soft inner bits, decoding these soft inner bits with an outer decoder, and using extrinsic information for the soft inner bits provided by the outer decoder to iteratively update the sub-set of dominant sequences of CPM symbols in the inner CPM detector.

Iterative non-coherent CPM decoder

The invention provides an adaptive frequency hopping spread-spectrum (FHSS) transmission system and method, which efficiently utilizes available transmission bandwidth, whilst providing robustness to jamming techniques in wireless communication systems. The proposed technique operates by transmitting a wide-band signal over multiple, single-carrier, parallel transmission subbands, which may occupy non-contiguous frequency regions. The proposed scheme exhibits significant gain in error rate performance, as compared to a data rate equivalent single-subband system in the presence of signal jamming and/or interference without a reduction in the transmission data rate nor an increase in transmitter power. In addition, the proposed system and method are adaptive and enable more efficient use of the available bandwidth for communicating, thus increasing the overall bandwidth utilization of the system.

Frequency hopping communication system

The present invention divides the available sub-carriers in an OFDM symbol window into N groups of sub-carriers wherein each group will be associated with sub-bands. In one embodiment, the sub-carriers in a group are spread throughout the range of sub-carriers to improve frequency diversity, and the sub-carriers assigned to any one group are separated by a constant offset. The sub-carriers in the group may be offset by an integer power of two. Within each group, sub-bands are defined using frequency hopping patterns among sub-carriers in the group from one OFDM symbol window to another. A pseudo-random pattern may be employed for sub-carrier mapping from one OFDM symbol window to the next to effectively distribute the sub-bands across the selected band of sub-carriers for the group.

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Ottawa, Canada

Colin Brown